ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (853,657)
  • Elsevier  (501,725)
  • American Chemical Society  (185,155)
  • American Physical Society  (82,843)
  • Springer Nature  (80,356)
  • Annual Reviews
  • 2020-2024  (2)
  • 2010-2014  (419,998)
  • 2005-2009  (347,080)
  • 1985-1989
  • 1980-1984  (79,260)
  • 1970-1974
  • 1930-1934  (7,321)
  • 2014  (223,254)
  • 2012  (196,746)
  • 2008  (176,499)
  • 2007  (170,583)
  • 1984  (79,260)
  • 1931  (7,321)
Collection
Source
Keywords
Publisher
Years
Year
Journal
Topic
  • 1
    facet.materialart.
    Unknown
    An expanded non-Arrhenian model for silicate melt viscosity: A treatment for metaluminous, peraluminous and peralkaline liquids (2007)
    Elsevier
    Details
    Publication Date: 2020-10-29
    Description: We present new viscosity measurements for melts spanning a wide range of anhydrous compositions including: rhyolite, trachyte, moldavite, andesite, latite, pantellerite, basalt and basanite. Micropenetration and concentric cylinder viscometry measurements cover a viscosity range of 10−1 to 1012 Pas and a temperature range from 700 to 1650 °C. These new measurements, combined with other published data, provide a high-quality database comprising ∼800 experimental data on 44 well-characterized melt compositions. This database is used to recalibrate the model proposed by Giordano and Dingwell [Giordano, D., Dingwell, D. B., 2003a. Non-Arrhenian multicomponent melt viscosity: a model. Earth Planet. Sci. Lett. 208, 337–349] for predicting the viscosity of natural silicate melts. The present contribution clearly shows that: (1) the viscosity (η)–temperature relationship of natural silicate liquids is very well represented by the VFT equation [log η=A+B/ (T−C)] over the full range of viscosity considered here, (2) the use of a constant high-T limiting value of melt viscosity (e.g., A) is fully consistent with the experimental data, (3) there are 3 different compositional suites (peralkaline, metaluminous and peraluminous) that exhibit different patterns in viscosity, (4) the viscosity of metaluminous liquids is well described by a simple mathematical expression involving the compositional parameter (SM) but the compositional dependence of viscosity for peralkaline and peraluminous melts is not fully controlled by SM. For these extreme compositions we refitted the model using a temperature-dependent parameter based on the excess of alkalies relative to alumina (e.g., AE/SM). The recalibrated model reproduces the entire database to within 5% relative error (e.g., RMSE of 0.45 logunits).
    Description: Published
    Description: 42–56
    Description: reserved
    Keywords: Viscosity ; Model ; Silicate melts ; Metaluminous ; Peraluminous ; Peralkaline ; 04. Solid Earth::04.01. Earth Interior::04.01.05. Rheology ; 04. Solid Earth::04.04. Geology::04.04.05. Mineralogy and petrology ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 717294 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    Experimental solidification of anhydrous latitic and trachytic melts at different cooling rates: the role of nucleation kinetics (2008)
    Elsevier
    Details
    Publication Date: 2020-10-29
    Description: Two sets of cooling experiments were run at atmospheric conditions for two anhydrous starting latitic and trachytic melts: 1) five cooling rates (25, 12.5, 3, 0.5, and 0.125 °C/min) between 1300° and 800 °C, and 2) a 11 0.5 °C/min cooling rate from 1300 °C with quench temperatures at 1200°, 1100°, 1000° and 900 °C. Trachytic run-products are invariably glassy. Nucleation is also suppressed in the latitic run-products at the three highest 13 cooling rates. Conversely, in the 0.5 and 0.125 °C/min runs, latites have a crystal content of 90 vol.%. The 14 phases are: plagioclase, clinopyroxene, glass and iron-bearing oxide (in order of abundance). The variable 15 quench temperatures, investigated by coupling experiments with Pt-wire and Pt- capsule sample containers inset 2,again did not produce crystallization of trachyte, whereas latitic samples are characterized by 10 vol.% of oxides, pyroxenes and plagioclase (in order of appearance), at temperature b1000 °C. Effects of (preferential) heterogeneous nucleation on sample holders, of superheating degree, and chemical species loss during cooling are absent for both melt compositions. The difference of solidification paths between these two silicate melts can be ascribed only to their small chemical differences. In comparison with calculated equilibrium conditions all the experimental latitic and trachytic run-products revealed strong kinetic effects, interpretable in the light of the nucleation theory. The glass- forming ability (GFA) of trachyte is higher, whereas their critical cooling rate (Rc) is lower (b0.125 °C/min), in comparison to latitic melts (RcN0.5 °C/min). The experimental results carried out in this study can be applied to lava flows and domes; trachytic lavas are able to flow for longer period with respect to latitic ones in a metastable condition. Glass-rich terrestrial lavas, i.e. obsidians, can be the result of sluggish nucleation kinetics due to the relative high polymerisation of evolved silicate melts.
    Description: Published
    Description: 91-101
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: crystallization ; lava flows ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Electrical conductivity of a phonotephrite from Mt. Vesuvius: the importance of chemical composition on the lectrical conductivity of silicate melts (2008)
    Elsevier
    Details
    Publication Date: 2020-10-29
    Description: The bulk electrical conductivity of the phonotephritic lava from the 1944 eruption of Mt Vesuvius was measured using complex impedance spectroscopy in a multianvil apparatus at 1 GPa and temperatures up to 700 °C. Melting experiments prior to the electrical measurements were also performed on this sample in a piston cylinder apparatus in order to gauge how bulk conductivity varies as a function of its melt fraction. Unlike the behaviour found in basaltic rocks in which conductivity increases with increasing melt fraction, we observe a conductivity decrease of the order of a factor of ten for samples at 700 °C ranging in melt fraction from 32 vol.% to completely molten.We attribute this anomalous behaviour to the progressive loss of highly conductive leucite upon melting. The addition of potassium to the melt phase, however, does not result in an increase of the total alkali concentration due to the melting of other mineral components. We also present an empirical model to predict the electrical conductivity of fully molten silicate liquids as a function of temperature and chemical composition, based on conductivity data for natural silicate liquids found in the literature. The inclusion of compositional terms reduces the error by more than a factor of four with respect to a composition independent, temperature-only parameterization.
    Description: Published
    Description: 192-201
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: JCR Journal
    Description: reserved
    Keywords: Electrical conductivity ; silicate melts ; partial melting ; Mt. Vesuvius ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    Extensional tectonics in the Amantea basin (Calabria, Italy): a comparison between structural and magnetic anisotropy data (2008)
    Elsevier
    Details
    Publication Date: 2020-11-19
    Description: We report on structural and anisotropy of magnetic susceptibility (AMS) results from the Upper Miocene sediments of the Amantea basin, located on the Tyrrhenian coast of the Calabrian Arc (Southern Italy). The stratigraphic succession of the basin is organized in three depositional sequences, separated by two major angular unconformities. Detailed geologica1 mapping and structural analysis demonstrate that the stratigraphic evolution of the Amantea basin is strongly controlled by a synsedimentary extensional tectonic regime. Severa1 NNE-SSW-trending norma1 fault arrays with large scatter in inclination values have been interpreted as due to a domino faulting mechanism, consistent with a WNW-ESE stretching direction. AMS data have been obtained for 13 sites, both in the not constrained in age first depositional sequence (3 sites), and in the upper Tortonian-lower Messinian clays from the second depositional sequence (10 sites). Al1 the sites show a strong magnetic foliation parallel to the bedding planes, and a well defined magnetic lineation subparallel to the local bedding dip directions. The magnetic lineations cluster around a WNW-ESE trend and are parallel to the stretching directions inferred by fault-slip analysis and basin architecture. These new data then confirm the possibility to use the magnetic lineation to map the strain trajectory in weakly deformed extensional sedimentary basins. Paleomagnetic data (from previous studies) show that the whole Calabrian block underwent a 15°-20° clockwise rotation probably in the Pleistocene, postdating the extensional tectonic events which controlled the Amantea basin geometry. Therefore we suggest for the Amantea basin an original E-W-oriented stretching direction, which may be considered as the older extensional direction characterizing the Late Miocene evolution of the southern Tyrrhenian Sea domain.
    Description: Published
    Description: 33-49
    Description: JCR Journal
    Description: reserved
    Keywords: magnetic fabric ; extentional tectonics ; Miocene ; Calabrian Arc ; Italy ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    Mechanisms for ground-surface fracturing and incipient slope failure associated with the 2001 eruption of Mt. Etna, Italy: analysis of ephemeral field data (2008)
    Elsevier
    Details
    Publication Date: 2020-11-26
    Description: During the July^August 2001 eruption of Mt. Etna development of extensional fractures/faults and grabens accompanied magma intrusion and subsequent volcanic activity. During the first days of the eruption, we performed an analysis of attitude, displacement and propagation of fractures and faults exposed on the ground surface in two sites, Torre del Filosofo and Valle del Leone, located along the same fracture system in the region surrounding the Valle del Bove depression on the eastern flank of Mt. Etna. Fractures and faults formed as the consequence of a shallow intruding dyke system that fed the several volcanic centres developed along the fracture system. The investigated sites differ in slope attitude and in geometrical relationships between fractures and slopes. In particular, the fracture system propagated parallel to the gentle slope (67‡ dip) in the Torre del Filosofo area, and perpendicular to the steep slope (V25‡ dip) in the Valle del Leone area. In the Torre del Filosofo area, slight graben subsidence and horizontal extension of the ground surface by about 3 m were recorded. In the Valle del Leone area, extensional faulting forming a larger and deeper graben with horizontal extension of the ground surface by about 10 m was recorded. For the Valle del Leone area, we assessed a downhill dip of 14‡ for the graben master fault at the structural level beneath the graben where the fault dip shallows. These results suggest that dyke intrusion at Mount Etna, and particularly in the region surrounding the Valle del Bove depression, may be at the origin of slope failure and subsequent slumps where boundary conditions, i.e. geometry of dyke, slope dip and initial shear stress, amongst others, favour incipient failures.
    Description: Published
    Description: 281-294
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: 3.2. Tettonica attiva
    Description: 3.5. Geologia e storia dei sistemi vulcanici
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: dykes ; extensional fractures ; grabens ; slope failures ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 6
    facet.materialart.
    Unknown
    P wave seismic velocity and Vp/Vs ratio beneath the Italian peninsula from local earthquake tomography (2008)
    Elsevier
    Details
    Publication Date: 2020-11-17
    Description: We investigate the P wave velocity structure and the Vp/Vs ratio beneath the Italian peninsula down to 100 and 60 km depth respectively by seismic travel time tomography. We invert data provided by the International Seismological Centre (ISC) (1997–2005), making use of some alternative strategies for the travel time approach in a well constrained and worldwide adopted code (SIMULPS). Resolution for the different layers is discussed and sensitivity analyses are performed through test inversions to explore the resolution characteristics of the model at different spatial scales. The resulting tomographic images provide a detailed sketch of the P wave anomalies, clearly showing, among the other features, the shape of the Ivrea body in the Western Alps, the upwelling of the oceanic crust in the Ligurian Sea and the slab under the Calabrian arc. They are less informative for the Vp/Vs ratio. Nevertheless, some features are very interesting and deserve further investigation like the anomalous decrease of the Vp/Vs ratio under the Ligurian Sea or the variations of the Vp/Vs ratio calculated in the first 10 km depth of the Apenninic region with respect to the lower values of the Alpine region at the same depth. The tomographic cross sections reveal a continuous superposition of two kinds of crusts (transitional over Adriatic) all along the peninsula but do not show any slab, intended as a clear, vertical downgoing high velocity material in either the northern or central Apennines.
    Description: Published
    Description: 1-23
    Description: 4T. Sismicità dell'Italia
    Description: JCR Journal
    Description: reserved
    Keywords: Seismic tomography ; Lithospheric structure ; Vp/Vs ratio ; 04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 7
    facet.materialart.
    Unknown
    Variability in the vertical structure of the water column and paleoproductivity reconstruction in the central-western Mediterranean during the Late Pleistocene (2008)
    Elsevier
    Details
    Publication Date: 2020-12-21
    Description: A sedimentary sequence spanning Marine Isotope Stage (MIS) 6 to MIS 2 in core LC07, recovered in the central Mediterranean, has been investigated in order to produce a high-resolution paleoceanographic reconstruction. The changes in productivity deduced from calcareous plankton relative abundances and independently confirmed by the BaXS fluctuations are linked to the stability of the water column which is mainly controlled by the water mass temperature. During glacial intervals, productivity was generally enhanced. Oligotrophic and warmer water masses with a deepened seasonal thermocline can be inferred for most of MIS5. The magnetic properties of the sediment show increased occurrences of North Africa dust in the central Mediterranean during cold phases, likely as a consequence of a more efficient erosive process triggered by southward displacement of the intertropical convergence zone. Although increases in both productivity and Saharan dust occurred during cold periods, the atmospheric inputs do not seem to contribute significantly to the fertilization of primary producers. A Shannon Index curve has been used to tentatively synthesize the variations of calcareous nannofossil assemblages through the last 150 kyr. The assemblage diversity sharply increased coincident with the transition from the penultimate glacial to the last interglacial, subsequently low diversity was gradually reached again in the last glacial.
    Description: Published
    Description: 26-41
    Description: 2.2. Laboratorio di paleomagnetismo
    Description: JCR Journal
    Description: reserved
    Keywords: calcareous nannofossils ; foraminifera ; paleoproductivity ; Late Pleistocene ; central mediterranean ; 03. Hydrosphere::03.01. General::03.01.06. Paleoceanography and paleoclimatology ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 04. Solid Earth::04.05. Geomagnetism::04.05.07. Rock magnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    The late Pleistocene pyroclastic deposits of the Campanian Plain: New insights into the explosive activity of Neapolitan volcanoes (2008)
    Elsevier
    Details
    Publication Date: 2020-12-21
    Description: The lithological and compositional characteristics of eighteen different pyroclastic deposits of Campanian origin, dated between 125 cal ky BP and 22 cal ky BP, were described. The pyroclastic deposits were correlated among different outcrops mainly located on the Apennine slopes that border the southern Campanian Plain. They were grouped in two main stratigraphic and chronologic intervals of regional significance: a) between Pomici di Base (22.03 cal ky BP; Somma–Vesuvius) and Campanian Ignimbrite (39 cal ky BP; Campi Flegrei) eruptions; and b) older than Campanian Ignimbrite eruption. Three new 14C AMS datings support the proposed correlations. Six eruptions were attributed to the Pomici di Base- Campanian Ignimbrite stratigraphic interval, while twelve eruptions are older than Campanian Ignimbrite. Of the studied deposits two originated from Ischia island, five are related to Campi Flegrei, and three to Somma– Vesuvius. Two eruptions have an uncertain correlation with Somma–Vesuvius or Campi Flegrei, while six eruptions remain of uncertain source. Minimum volumes of five eruptions were assessed, ranging between 0.5 km3 and 4 km3. Two of the studied deposits were correlated with Y-3 and X-5 tephra layers, which are widely dispersed in the central Mediterranean area. The new stratigraphic and chronologic data provide an upgraded chrono-stratigraphy for the explosive activity of Neapolitan volcanoes in the period between 125 and 22 cal ky BP.
    Description: Published
    Description: 19–48
    Description: 3.5. Geologia e storia dei sistemi vulcanici
    Description: JCR Journal
    Description: reserved
    Keywords: Neapolitan volcanoes ; late Pleistocene ; explosive eruptions ; Somma–Vesuvius ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 9
    facet.materialart.
    Unknown
    Carbon dioxide degassing from Tuscany and Northern Latium (Italy) (2008)
    Elsevier
    Details
    Publication Date: 2021-01-07
    Description: The CO2 degassing process from a large area on the Tyrrhenian side of central Italy, probably related to the input into the upper crust of mantle fluids, was investigated in detail through the geochemical study of gas emissions and groundwater. Mass-balance calculations and carbon isotopes show that over 50% of the inorganic carbon in regional groundwater is derived from a deep source highlighting gas−liquid separation processes at depth. The deep carbonate−evaporite regional aquifer acts as the main CO2 reservoir and when total pressure of the reservoir fluid exceeds hydrostatic pressure, a free gas phase separates from the parent liquid and escapes toward the surface generating gas emissions which characterise the study area. The distribution of the CO2 flux anomalies and the location of high PCO2 springs and gas emissions suggest that the storage and the expulsion of the CO2 toward the atmosphere are controlled by the geological and structural setting of the shallow crust. The average CO2 flux and the total amount of CO2 discharged by the study area were computed using surface heat flow, enthalpy and CO2 molality of the liquid phase circulating in the deep carbonate−evaporite aquifer. The results show that the CO2 flux varies from 1×104 mol y−1 km−2 to 5×107 mol y−1 km−2, with an average value of 4.8×106 mol y−1 km−2, about five times higher than the value of 1×106 mol y−1 derived by Kerrick et al. [Kerrick, D.M., McKibben, M.A., Seward, T.M., Caldeira, K., 1995. Convective hydrothermal CO2 emission from high heat flow regions. Chem. Geol. 121, 285–293] as baseline for terrestrial CO2 emissions. The total CO2 discharged from the study area is 0.9×1011 mol y−1, confirming that Earth degassing from Tyrrhenian central Italy is a globally relevant carbon source
    Description: Published
    Description: 89–102
    Description: 2.4. TTC - Laboratori di geochimica dei fluidi
    Description: 4.5. Degassamento naturale
    Description: JCR Journal
    Description: reserved
    Keywords: Earth degassing ; carbon dioxide ; CO2 flux ; groundwater ; 04. Solid Earth::04.02. Exploration geophysics::04.02.01. Geochemical exploration ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 10
    facet.materialart.
    Unknown
    Extensional tectonics on Sardinia (Italy): insights into the arc–back-arc transitional regime (2008)
    Elsevier
    Details
    Publication Date: 2021-05-12
    Description: Although the tectonic features and stress regime typical for accretionary complexes and back-arc domains have been widely documented so far, few are known on the transitional zone separating these two systems. Here we report on structural analysis and anisotropy of magnetic susceptibility (AMS) results from Eocene–Pliocene sediments exposed in western Sardinia. From late Oligocene to middle Miocene, the studied area was located between the Alpine–Apennine wedge to the east, which was undergoing shortening and accretion, and the Liguro–Provenc al basin, undergoing extension and spreading. We find that, prior to the formation of the Liguro–Provenc al basin, the middle Eocene–lower Oligocene sediments cropping out at the southwesternmost edge of Sardinia were subjected to NE–SW shortening (in present-day coordinates), in agreement with recently reported geological information. Conversely, the upper Oligocene–Pliocene sedimentary sequences record a different evolutionary stage of extensional processes. Upper Oligocene–middle–upper Burdigalian sediments clearly show a N–S-oriented magnetic lineation that can be related to extensional direction along the prevalent E–W-oriented normal faults. On the other hand, no magnetic lineation has been detected in upper Burdigalian–Serravallian sediments, which mark the end of the first rifting process in Sardinia, which likely coincides with the rift-to-drift transition at the core of the Liguro–Provençal basin. Finally, a NE–SW extension is observed in two Tortonian–Pliocene sites at the northwestern margin of the NNW–SSE-oriented Campidano graben. Our study confirms that AMS may represent a valuable strain-trajectory proxy and significantly help to unravel the characters of temporally superimposed tectonic events.
    Description: Published
    Description: 213-232
    Description: 3.4. Geomagnetismo
    Description: JCR Journal
    Description: reserved
    Keywords: Back-arc basin ; Magnetic anisotropy susceptibility (AMS) ; Sardinia ; Mediterranean area ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 11
    facet.materialart.
    Unknown
    Comparison of a new expert elicitation model with the Classical Model, equal weights and single experts, using a cross-validation technique (2012)
    Elsevier
    Details
    Publication Date: 2021-05-17
    Description: The problem of ranking and weighting experts' performances when quantitative judgments are being elicited for decision support is considered. A new scoring model, the Expected Relative Frequency model, is presented, based on the closeness between central values provided by the expert and known values used for calibration. Using responses from experts in five different elicitation datasets, a cross-validation technique is used to compare this new approach with the Cooke Classical Model, the Equal Weights model, and individual experts. The analysis is performed using alternative reward schemes designed to capture proficiency either in quantifying uncertainty, or in estimating true central values. Results show that although there is only a limited probability that one approach is consistently better than another, the Cooke Classical Model is generally the most suitable for assessing uncertainties, whereas the new ERF model should be preferred if the goal is central value estimation accuracy.
    Description: Published
    Description: 1292-1310
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: JCR Journal
    Description: reserved
    Keywords: Expert elicitation ; Expert judgement ; Subjective probability ; Cross-validation ; Cooke Classical Model ; Expected Relative Frequency model ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 05. General::05.01. Computational geophysics::05.01.04. Statistical analysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 12
    facet.materialart.
    Unknown
    A major change in the sedimentation regime in the Crotone Basin (Southern Italy) around 3.7-3.6 Ma (2014)
    Elsevier
    Details
    Publication Date: 2021-05-17
    Description: The Lower Pliocene succession of the Crotone Basin (Calabrian Arc, Southern Italy) is mainly comprised of blue-grey marly clay with good magnetic properties. Here the bio-magnetostratigraphic data indicate a mean sedimentation rate of about 12–15 cm/kyr. Around 3.7–3.6 Ma a major change in the sedimentation regime occurred: the blue-grey hemipelagic marls grade rapidly into silty marls with a significant increase in the terrigenous fraction and with abundant siliceous remains throughout the whole interval. Magnetic properties of these sediments are very poor, but an integrated calcareous plankton biostratigraphy (foraminifera and nannofossils) infers a high average sedimentation rate (about 50–60 cm/kyr). The abrupt onset of this sedimentation regime in the Crotone Basin is contemporaneous with a major unconformity already recognized in the northern sector of the basin, part of amajor reorganization phase in the whole Apenninic–Maghrebid Chain known as “Globorotalia puncticulata event”. Reports of coeval siliceous sediments in other marginal basins of the Apennines (Southern Calabria, Southern and Northern Apennines) suggest that this “siliceous event” might have been regionally extensive, having important palaeoceanographical implications.We infer that the “siliceous event” is characterized by a combined tectonic- and climate-induced change in palaeoceanographic conditions. The tectonic triggering factors may have been linked to two synchronous events in the Tyrrhenian–Apennine system: 1) the shortening event also known as “G. puncticulata event”, and 2) the coeval opening of the Vavilov Basin in the Tyrrhenian Sea which yielded profound influences in terms of physiography and characteristics of the Crotone Basin. The consequent uplift of the Southern Apennines would have increased sediment supply and availability of silica, resulting in eutrophication and enhanced silica preservation. Strong winter mixing and possibly upwelling conditions could have increased primary productivity during heavy isotope stages Gi4, Gi2 and MG8, at the onset of the “siliceous event”. This important event, lasting from ca. 3.6 Ma to ca. 3.2 Ma, would have recorded a peculiar transitional period before further climatic deterioration and more drastic palaeoceanographic changes occurred around 3.1 Ma, leading to cyclic sapropel deposition in the whole of the Mediterranean sea.
    Description: Published
    Description: 398-410
    Description: 1A. Geomagnetismo e Paleomagnetismo
    Description: JCR Journal
    Description: restricted
    Keywords: Biostratigraphy ; Magnetostratigraphy ; Pliocene ; Calabrian Arc ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 13
    facet.materialart.
    Unknown
    Pegaso: an ultra-light long duration stratospheric payload for polar regions flights (2012)
    Elsevier
    Details
    Publication Date: 2021-06-21
    Description: Stratospheric balloons are powerful and affordable tools for a wide spectrum of scientific investigations that are carried out at the stratosphere level. They are less expensive compared to satellite projects and have the capability to lift payloads from a few kilograms to a couple of tons or more, well above the troposphere, for more than a month. Another interesting feature of these balloons, which is not viable in satellites, is the short turnaround time, which enables frequent flights. We introduce the PEGASO (Polar Explorer for Geomagnetism And other Scientific Observations) project, a stratospheric payload designed and developed by the INGV (Istituto Nazionale di Geofisica e Vulcanologia), Rome and La Sapienza University, Rome. The project was sponsored by the PNRA (Progetto Nazionale di Ricerche in Antartide), Italy (Peterzen et al., 2003). This light payload (10 kg) was used by the Italian Space Agency (ASI) and Andoya Rocket Range (ARR) for five different scientific missions. PEGASO carries a 3-component flux-gate magnetometer, uses a solar cell array as the power source and has a GPS location system. The bi-directional telemetry system for data transfer and the remote control system were IRIDIUM based
    Description: INGV, PNRA, ASI, ARR, CNR, La Sapienza
    Description: Published
    Description: Beijing, China
    Description: 1.10. TTC - Telerilevamento
    Description: open
    Keywords: LDB ; Polar areas ; Magnetometer ; Stratosphere ; 05. General::05.04. Instrumentation and techniques of general interest::05.04.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Conference paper
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 14
    facet.materialart.
    Unknown
    Enhanced rainfall in the Western Mediterranean during deposition of sapropel S1: stalagmite evidence from Corchia cave (Central Italy) (2007)
    Elsevier
    Details
    Publication Date: 2021-06-16
    Description: A stable isotope record from a stalagmite collected from Antro del Corchia cave (Apuan Alps, Central Italy), supported by 17 uranium-series ages, indicates enhanced regional rainfall between ca 8.9 and 7.3 kyr cal. BP at the time of sapropel S1 deposition. Within this phase, the highest rainfall occurred between 7.9 and 7.4 kyr cal. BP. Comparison with different marine and lake records, and in particular with the Soreq Cave record (Israel), suggests substantial in-phase occurrence of enhanced rainfall between the Western and Eastern Mediterranean basins. There is no convincing evidence for major climatic change at the time of the “8.2 kyr event”.
    Description: Published
    Description: 279-286
    Description: 3.8. Geofisica per l'ambiente
    Description: JCR Journal
    Description: reserved
    Keywords: climatic change ; olocene ; sapropel S1 ; stalagmite ; 03. Hydrosphere::03.01. General::03.01.06. Paleoceanography and paleoclimatology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 15
    facet.materialart.
    Unknown
    Shear-Wave Velocity Models and Seismic Sources in Campanian volcanic areas:Vesuvio and Campi Flegrei (2007)
    Elsevier
    Details
    Publication Date: 2020-09-29
    Description: This chapter summarizes a comparative study of shear-wave velocity models and seismic sources in the Campanian volcanic areas of Vesuvius and Phlegraean Fields. These velocity models were obtained through the nonlinear inversion of surfacewave tomography data, using as a priori constraints the relevant information available in the literature. Local group velocity data were obtained by means of the frequency–time analysis for the time period between 0.3 and 2 s and were combined with the group velocity data for the time period between 10 and 35 s from the regional events located in the Italian peninsula and bordering areas and two station phase velocity data corresponding to the time period between 25 and 100 s. In order to invert Rayleigh wave dispersion curves, we applied the nonlinear inversion method called hedgehog and retrieved average models for the first 30–35km of the lithosphere, with the lower part of the upper mantle being kept fixed on the basis of existing regional models. A feature that is common to the two volcanic areas is a low shear velocity layer which is centered at the depth of about 10 km, while on the outside of the cone and along a path in the northeastern part of the Vesuvius area this layer is absent. This low velocity can be associated with the presence of partial melting and, therefore, may represent a quite diffused crustal magma reservoir which is fed by a deeper one that is regional in character and located in the uppermost mantle. The study of seismic source in terms of the moment tensor is suitable for an investigation of physical processes within a volcano; indeed, its components, double couple, compensated linear vector dipole, and volumetric, can be related to the movements of magma and fluids within the volcanic system. Although for many recent earthquake events the percentage of double couple component is high, our results also show the presence of significant non-double couple components in both volcanic areas.
    Description: Published
    Description: 287-309
    Description: reserved
    Keywords: NONE ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
    Format: 8247786 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 16
    facet.materialart.
    Unknown
    The effect of H2O on the viscosity of K-trachytic melts at magmatic temperatures (2007)
    Elsevier
    Details
    Publication Date: 2020-10-29
    Description: Viscosity of hydrous trachytes from the Agnano Monte Spina eruption (Phlegrean Fields, Italy) has been determined at 1.0 GPa and temperatures between 1200 and 1400 °C using the falling sphere method in a piston cylinder apparatus. The H2O content in the melts ranged from 0.18 to 5.81 wt.%. These high-temperature hydrous viscosities, along with previous ones determined at low-temperature (anhydrous and hydrous) and at high-temperature (anhydrous), at 1 atm on the same melt composition, represent the only complete viscosity data set available for K-trachyticmelts, frommagmatic to volcanic conditions.Viscosity decreases with increasing temperature andwater content in the melt.At constant temperature, viscosity appears to significantly decreasewhen the first wt.% ofH2Ois added.At H2O content higher than 3 wt.% the effect of temperature on viscosity is slight. Moreover, the deviation from Arrhenian behaviour towards greater “fragility” occurs with increasing water content. We combined low- and high-temperature viscosities (also from literature) and parameterized themby the use of a modified Vogel–Fulcher–Tamman equation, which accommodates the non-Arrhenian temperature dependence ofmelt viscosity.Moreover, in order to explore the extent to which the improved knowledge of Agnano Monte Spina trachyte viscosity may affect simulation of volcanic eruption at Phlegrean Fields, we included our viscosity models in numerical simulations of magma flow and fragmentation along volcanic conduits. These simulations show that the new parameterizations (and hence the new equations) give stronger predictions in the temperature interval relevant for magmatic and eruptive processes.
    Description: Published
    Description: 124-137
    Description: JCR Journal
    Description: reserved
    Keywords: Viscosity ; Trachyte ; Falling sphere method ; Vogel–Fulcher–Tamman equation ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 17
    facet.materialart.
    Unknown
    Monitoring ash emission episodes at Mt. Etna: the 16 November 2006 case study (2008)
    Elsevier
    Details
    Publication Date: 2020-11-17
    Description: Mt. Etna in Sicily (Italy) is one of the best monitored basaltic volcanoes in the world due to the frequent eruptions from its summit and flanks. Routine monitoring carried out by the Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, for surveillance purposes permits following the evolution of volcanic events. In this paper, a description of the ash monitoring system as occurred during the August-December 2006 summit eruption at the Southeast Crater (SEC) is shown. This eruption was characterized by lava flow effusions and vigorous Strombolian activity. Eighteen paroxysmal episodes occurred up to the end of November, forming weak ash plumes accompanied by moderate tephra fallout over Etna’s slopes. During these events, we applied a multidisciplinary approach to promptly monitor the paroxysmal activity and the associated tephra fallout, through analysis from seismic tremor and observation from live-cameras, sampling operations, mapping and analysis of the deposit. During the most significant episodes, we carried out textural and grain-size analysis on tephra samples and evaluated the whole grain-size deposit and the erupted volume, while numerical simulations of tephra dispersal allowed better understanding eruptive dynamics. An example of this methodology is applied to the 16 November episode, during which seismic tremor furnished important constraints on the chronology. This paroxysmal eruption produced light fallout on the north-east sector of the volcano for about ten hours and a number of debris-avalanches over the slopes of the SEC cone. The erupted deposit was composed for the most part of lithic components and characterized by a whole grain-size distribution centered on 2.2 , while its total mass was evaluated 7 x 106 kg. On the whole, such integrated studies help to obtain information on magma fragmentation and eruptive mechanisms, to characterize the explosive styles shown by Etna and finally, to better approach the monitoring of imminent eruptions.
    Description: FIRB Italian project “Sviluppo Nuove Tecnologie per la Protezione e Difesa del Territorio dai Rischi Naturali” funded by Italian Minister of University and Research
    Description: Published
    Description: 123-134
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: JCR Journal
    Description: open
    Keywords: Mt. Etna ; volcanic ash monitoring ; tephra deposit ; 2006 eruption ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 18
    facet.materialart.
    Unknown
    Carbonate-derived CO2 purging magma at depth: Influence on the eruptive activity of Somma-Vesuvius, Italy (2012)
    Elsevier
    Details
    Publication Date: 2020-11-30
    Description: Mafic phenocrysts from selected products of the last 4 ka volcanic activity at Mt. Vesuvius were investigated for their chemical and O-isotope composition, as a proxy for primary magmas feeding the system. 18O/16O ratios of studied Mg-rich olivines suggest that near-primary shoshonitic to tephritic melts experienced a flux of sedimentary carbonate-derived CO2, representing the early process of magma contamination in the roots of the volcanic structure. Bulk carbonate assimilation (physical digestion) mainly occurred in the shallow crust, strongly influencing magma chamber evolution. On a petrological and geochemical basis the effects of bulk sedimentary carbonate digestion on the chemical composition of the near-primary melts are resolved from those of carbonate-released CO2 fluxed into magma. An important outcome of this process lies in the effect of external CO2 in changing the overall volatile solubility of the magma, enhancing the ability of Vesuvius mafic magmas to rapidly rise and explosively erupt at the surface.
    Description: Published
    Description: 84-95
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: JCR Journal
    Description: reserved
    Keywords: stable-isotope ; magma geochemistry ; CO2-degassing ; Vesuvius ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 19
    facet.materialart.
    Unknown
    The viscosity of shoshonitic melts (Vulcanello Peninsula, Aeolian Islands, Italy): insight on the magma ascent in dikes (2007)
    Elsevier
    Details
    Publication Date: 2021-01-14
    Description: The viscosity of shoshonitic melts from Vulcanello Peninsula (Vulcano Island, Italy) is experimentally determined at temperatures between 733 K and 1673 K. The water content of the melts varies from 0.03 to 4.75 wt% H2O. The micropenetration technique is employed at ambient pressure in the high viscosity range (109-1012 Pa·s). Falling sphere(s) experiments are performed at 500 and 2000 MPa in the low viscosity range (100.5-103 Pa·s). Results show a decrease of about 2 orders of magnitude in viscosity if ~ 3 wt% of water is added to the dry melt at 1300 K. At high temperature the viscosity of Vulcanello melts is intermediate between that of andesitic and basaltic melts. In contrast, at low temperatures (≤1050 K), the shoshonitic melt is characterized by a lower viscosity with respect to the two previous melts. Based on our new data set, a calculation model is proposed to predict the viscosity of the shoshonitic melts as a function of temperature and water content. The viscosity data are used to constrain the ascent velocity of shoshonitic magmas from Vulcanello within dikes. Using petrological data (temperature and crystal content of the magma) and volcanological information (geometrical parameters of the eruptive fissure and depth of magma storage), we estimate the time scale for the ascent of magma from the main reservoir to the surface. Results show time scales in the order of hours to few days. We conclude that the rapid ascent of poorly evolved melts from Moho depths should be taken into account for the hazard assessment of Vulcano Island.
    Description: Published
    Description: 89-102
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: JCR Journal
    Description: open
    Keywords: dikes ; ascent velocity ; 04. Solid Earth::04.01. Earth Interior::04.01.05. Rheology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 20
    facet.materialart.
    Unknown
    Viscosity of andesite melts and its implication for magma mixing prior to Unzen 1991-1995 eruption (2008)
    Elsevier
    Details
    Publication Date: 2021-01-14
    Description: The viscosity of an iron-bearing melt with composition similar to Unzen andesite was determined experimentally in the high (109-1010.5 Pa·s) and low (5-1000 Pa·s) viscosity range using a parallel plate viscometer and the falling sphere method, respectively. Falling sphere experiments were carried out in an internally heated argon pressure vessel and in a piston cylinder apparatus at 1323 to 1573 K and 200 to 2000 MPa. Creep experiments were performed in the temperature range of 747 - 845 K at 300 MPa. The water content of the melt varies from nominally dry to 6.2 wt% H2O. The Fe2+/Fetot ratio was determined for each sample in the quenched glass using a colorimetric method. Pressure has minor influence on the viscosity compared with the effect of temperature, water content (main compositional parameter controlling the viscosity) or with the Fe2+/Fetot ratio (especially important at low water content of the melt). Based on our new viscosity data and literature data with measured Fe2+/Fetot ratio we propose a new empirical equation to estimate the viscosity η (in Pa·s) of andesitic melts as a function of temperature T (in K), water content w (in wt%) and Fe2+/Fetot ratio. The derived relationship reproduces the experimental data (87 in total) in the viscosity range from 100.5 to 1013 Pa·s with a 1σ standard deviation of 0.17 log units. However, application of this calculation model is limited to Fe2+/Fetot〉0.3 and to temperatures above Tg. Moreover, in the high viscosity range the variation of viscosity with water content is constrained only by few experimental data and needs verification by additional measurements. The viscosity data are used to interpret mixing processes in the Unzen magma chamber prior to 1991-1995 eruption. We demonstrate that the viscosities of the rhyolite and andesite melts from the two end-member magmas are nearly identical prior and during mixing, enabling efficient magma mixing.
    Description: Published
    Description: 208-217
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: JCR Journal
    Description: open
    Keywords: viscosity ; andesite melt ; dissolved water ; redox state of iron ; Unzen ; magma mixing ; 04. Solid Earth::04.04. Geology::04.04.07. Rock geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 21
    facet.materialart.
    Unknown
    Validation of the FALL3D ash dispersion model using observations of the 2010 Eyjafjallajökull volcanic ash clouds (2012)
    Elsevier
    Details
    Publication Date: 2021-05-17
    Description: During AprileMay 2010 volcanic ash clouds from the Icelandic Eyjafjallajökull volcano reached Europe causing an unprecedented disruption of the EUR/NAT region airspace. Civil aviation authorities banned all flight operations because of the threat posed by volcanic ash to modern turbine aircraft. New quantitative airborne ash mass concentration thresholds, still under discussion, were adopted for discerning regions contaminated by ash. This has implications for ash dispersal models routinely used to forecast the evolution of ash clouds. In this new context, quantitative model validation and assessment of the accuracies of current state-of-the-art models is of paramount importance. The passage of volcanic ash clouds over central Europe, a territory hosting a dense network of meteorological and air quality observatories, generated a quantity of observations unusual for volcanic clouds. From the ground, the cloud was observed by aerosol lidars, lidar ceilometers, sun photometers, other remote-sensing instruments and in-situ collectors. From the air, sondes and multiple aircraft measurements also took extremely valuable in-situ and remote-sensing measurements. These measurements constitute an excellent database for model validation. Here we validate the FALL3D ash dispersal model by comparing model results with ground and airplane-based measurements obtained during the initial 14e23 April 2010 Eyjafjallajökull explosive phase. We run the model at high spatial resolution using as input hourlyaveraged observed heights of the eruption column and the total grain size distribution reconstructed from field observations. Model results are then compared against remote ground-based and in-situ aircraft-based measurements, including lidar ceilometers from the German Meteorological Service, aerosol lidars and sun photometers from EARLINET and AERONET networks, and flight missions of the German DLR Falcon aircraft. We find good quantitative agreement, with an error similar to the spread in the observations (however depending on the method used to estimate mass eruption rate) for both airborne and ground mass concentration. Such verification results help us understand and constrain the accuracy and reliability of ash transport models and it is of enormous relevance for designing future operational mitigation strategies at Volcanic Ash Advisory Centers.
    Description: Published
    Description: 165-183
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: JCR Journal
    Description: restricted
    Keywords: Volcanic ash dispersion ; Numerical model ; Model validation ; 2010 Eyjafjallajökull eruption ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 22
    facet.materialart.
    Unknown
    Engineering ground motion record selection in the ITalian ACcelerometric Archive (2012)
    Elsevier
    Details
    Publication Date: 2021-06-21
    Description: This paper introduces REXELite, an internet version of REXEL, a software for automatic selection of ground motion suites for nonlinear dynamic analysis of structures. REXELite was developed with the aim of integrating an advanced earthquake records’ repository, such as the ITalianACcelerometricArchive (ITACA), with a tool to define seismic input for engineering seismic analysis according to international standards (with priority to Europe). In fact, REXELite allows to define target design spectra according either to Eurocode 8 or to the Italian building code, and to search ITACA for suitable sets of seven records (comprised of one or two horizontal ground motion components) matching such target spectra: on average, in a user-specified period range, and with the desired tolerance. The records in the set also have, individually and according to some criteria, the most similar spectral shape with respect to that of the code. Selection options include magnitude, source-to-site distance, soil conditions and, if desired, linear scaling of records to reduce further record-to-record variability of the selected suite.This paper introduces REXELite, an internet version of REXEL, a software for automatic selection of ground motion suites for nonlinear dynamic analysis of structures. REXELite was developed with the aim of integrating an advanced earthquake records’ repository, such as the ITalianACcelerometricArchive (ITACA), with a tool to define seismic input for engineering seismic analysis according to international standards (with priority to Europe). In fact, REXELite allows to define target design spectra according either to Eurocode 8 or to the Italian building code, and to search ITACA for suitable sets of seven records (comprised of one or two horizontal ground motion components) matching such target spectra: on average, in a user-specified period range, and with the desired tolerance. The records in the set also have, individually and according to some criteria, the most similar spectral shape with respect to that of the code. Selection options include magnitude, source-to-site distance, soil conditions and, if desired, linear scaling of records to reduce further record-to-record variability of the selected suite.
    Description: Published
    Description: 1761-1778
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: reserved
    Keywords: Response spectrum matching ; ITACA ; 04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 23
    facet.materialart.
    Unknown
    Relationships between magmatism and tectonics in a continental rift: The Pantelleria Island region (Sicily Channel, Italy) (2008)
    Elsevier
    Details
    Publication Date: 2021-07-14
    Description: Field geological data of the Pantelleria Island, a large Late Quaternary volcano located in the Sicily Channel rift zone, integrated with offshore geophysical information, are used to derive the structural setting of the Island and the surrounding region, and to analyse the relationships between tectonics and magmatism. Field work shows that the principal faults exposed on the Island fall into two systems trending NNE–SSW and NW–SE. Mapped faults from offshore multichannel seismic profiles show similar trends, and some of them represent the offshore extension of the Pantelleria Island structures. The NW–SE faults bound the Pantelleria Graben, one of the three main depressions formed since the Late Miocene–Early Pliocene within the African continental platform, which compose the Sicily Channel rift zone. A 3-D Moho depth geometry, derived from inversion of Bouguer gravity data, shows a significant uplift of the discontinuity up to 16–17 km beneath the westernmost part of the Pantelleria Graben and beneath the Pantelleria Island; it lows rapidly to 24–25 km away from the graben northeastward and south-westward. The Moho uplift could explain the presence of a shallow magma chamber in the southern part of the Island, where processes of magmatic differentiation are documented. Geological and geophysical data suggest that the northwestern part of the Sicily Channel is presently dominated by a roughly E–W directed extensional regime. Crustal cracking feeding the Quaternary volcanism could be also related to this extensional field that would be further responsible for the development of the N–S trending volcanic belt that extends in the Sicily Channel from Lampedusa Island to the Graham Bank. This mode of deformation is confirmed also by geodetic data. This implies that in the northwestern part of the Sicily Channel, the E–W extension replaced the NE–SW crustal stretching that originated the NW-trending tectonic depressions constituting the rift zone. © 2008 Elsevier B.V. All rights reserved.
    Description: Published
    Description: 32-46
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: reserved
    Keywords: Pantelleria Island ; Channel rift zone ; structural analysis ; Quaternary volcanism ; gravity modelling ; tectonic extension ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 24
    facet.materialart.
    Unknown
    Forecasting Lava Flow Hazard during the 2006 Etna Eruption: Using the Magflow Cellular Automata Model (2008)
    Elsevier
    Details
    Publication Date: 2020-11-16
    Description: The MAGFLOW cellular automata model was able to fairly accurately reproduce the time of the lava flow advance during the 2006 Etna eruption leading to very plausible flow predictions. MAGFLOW is intended for use in emergency response situations during an eruption to quickly forecast the lava flow path over some time interval from the immediate future to a long-time forecast. Major discrepancies between the observed and simulated paths occurred in the early phase of the 2006 eruption due to an underestimation of the initial flow rate, and at the time of the overlapping with the 2004-2005 lava flow. Very good representations of the areas likely to be inundated by lava flows were obtained when we adopt a time-varying effusion rate and include the 2004-2005 lava flow field in the Digital Elevation Model (DEM) of topography.
    Description: Published
    Description: 1050-1060
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: JCR Journal
    Description: open
    Keywords: Lava Flow ; Etna volcano ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.01. Computational geophysics::05.01.02. Cellular automata, fuzzy logic, genetic alghoritms, neural networks ; 05. General::05.01. Computational geophysics::05.01.05. Algorithms and implementation
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 25
    facet.materialart.
    Unknown
    Proximal tephra hazards: Recent eruption studies applied to volcanic risk in the Auckland volcanic field, New Zealand (2007)
    Elsevier
    Details
    Publication Date: 2020-11-30
    Description: Auckland, New Zealand is unique in being a metropolitan area built on an active volcanic field. Despite the small size and intensity of Auckland eruptions, the risk from tephra fall is high because of the high density of buildings and lifelines. The nature of this threat can be evaluated by comparisons with historical Strombolian and Hawaiian eruptions, which have occurred in non-populated areas. Cone-building phases of such eruptions are typically protracted, i.e., weeks to months in duration, prolonging the period during which emergency managers will have to fine tune mitigation for numerous parameters such as fluctuations in intensity and wind shifts. Rapid cone growth during future eruptions will define a region of some 30 to 100 ha where complete destruction will occur on a time scale of hours. The cost of this destruction is likely to range between NZ$200M and NZ$1.4B (ca. US$130M to US$900M). Beyond this, we have modeled the cumulative long-term effect of the build-up of a downwind blanket of lapilli and ash by estimating accumulation rates for three phases of the 1959 Kīlauea Iki eruption in Hawaii. The effect of changing wind direction was evaluated using low-level wind data from Auckland. These results show that intervals between 4 and 100 h will lapse before onset of significant damage to buildings.
    Description: Published
    Description: 138-149
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: JCR Journal
    Description: reserved
    Keywords: tephra hazard ; Auckland volcanic field ; cone growth ; tephra fall ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 26
    facet.materialart.
    Unknown
    Contemporary crustal extension in the Umbria–Marche Apennines from regional CGPS networks and comparison between geodetic and seismic deformation (2008)
    Elsevier
    Details
    Publication Date: 2020-11-16
    Description: Here we report the results of the analysis of a GPS velocity field in the Umbria–Marche Apennines (central Italy) obtained from the integration of diverse geodetic networks. The velocity field obtained shows a high degree of consistency both spatially and in terms of comparison with independent information, despite the limited time span of some GPS stations. Starting from the velocity field we derive a continuous strain rate field applying a spline interpolation technique which provide a smooth estimate of the deformation field. The main feature of the resulting strain rate field is a continuous high (N50 nanostrain/year) strain rate belt coincident with the area of largest historical and instrumental seismic release. The model directions of the principal axes agree with geological and seismological information indicating NE–SW extension. We transform the strain rate field into geodetic moment rate using the Kostrov formula to evaluate the potential seismic activity of the region and compare it with actual seismic release in the last 720 years from MwN5.5 earthquakes. This comparison highlights a large possible deficit in the seismic release with respect to the overall potential seismic activity, particularly concentrated in the northern part of the study area. This discrepancy can be resolved with either a large amount of seismicity to be released in the near future or significant aseismic slip and deformation.
    Description: Published
    Description: 3-12
    Description: 2T. Deformazione crostale attiva
    Description: JCR Journal
    Description: reserved
    Keywords: GPS ; crustal deformation ; Northen Apennines ; 04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 27
    facet.materialart.
    Unknown
    Trench investigation on the main strand of the Boconó fault in its central section, at Mesa del Caballo, Mérida Andes, Venezuela (2008)
    Elsevier
    Details
    Publication Date: 2020-11-25
    Description: The Mesa del Caballo trench assessment confirms the Holocene activity of the main strand of the Boconó fault at the Apartaderos pull-apart basin. Fifteen earthquakes, of which fourteen have been radiocarbon dated, have been recognized, spanning the last 20,500 yr. Recurrence intervals of these ≥7 magnitude events are variable. The dominant mode of recurrence is 400–450 yr, and the second one is 900 yr. Eventually some events are 1400–1800 yr apart. We suspect that our seismic record may be incomplete. This could be easily justified by several conditions: most of the earthquake recognitions is based on open-crack filling and they superpose spatially (eventually masking or destroying older fills), trenching may miss some events because the fault is made of en echelon Riedel shears, and a short return period may lead to faint differences between paleosoils few hundreds years of age apart. This trench also images an older activity of the fault, as evidenced by plentiful earthquake-triggered liquefaction features, as well as slumping and rotational sliding. By comparing paleoseismic results between the Morro de Los Hoyos and Mesa del Caballo trenches, it appears that both fault strands bounding the Apartaderos pull-apart basin move simultaneously. Besides, the main strand also coseismically slips twice in between those common events. In other words, the seismic scenario could be that the northern strand recurs every 1200–1350 yr while the southern does every 400– 450 yr. This is also in agreement with a respective slip share of 25 and 75% of the 9–10 mm/yr average slip of the Boconó fault in the Mérida Andes central sector.
    Description: Published
    Description: 38-53
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: reserved
    Keywords: Active faults ; South America ; Paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 28
    facet.materialart.
    Unknown
    Paleomagnetic analysis of curved thrust belts reproduced by physical models (2008)
    Elsevier
    Details
    Publication Date: 2020-12-14
    Description: This paper presents a new methodology for studying the evolution of curved mountain belts by means of paleomagnetic analyses performed on analogue models. Eleven models were designed aimed at reproducing various tectonic settings in thin-skinned tectonics. Our models analyze in particular those features reported in the literature as possible causes for peculiar rotational patterns in the outermost as well as in the more internal fronts. In all the models the sedimentary cover was reproduced by frictional low-cohesion materials (sand and glass micro-beads), which detached either on frictional or on viscous layers. These latter were reproduced in the models by silicone. The sand forming the models has been previously mixed with magnetite-dominated powder. Before deformation, the models were magnetized by means of two permanent magnets generating within each model a quasi-linear magnetic field of intensity variable between 20 and 100 mT. After deformation, the models were cut into closely spaced vertical sections and sampled by means of 1x1-cm Plexiglas cylinders at several locations along curved fronts. Care was taken to collect paleomagnetic samples only within virtually undeformed thrust sheets, avoiding zones affected by pervasive shear. Afterwards, the natural remanent magnetization of these samples was measured, and alternating field demagnetization was used to isolate the principal components. The characteristic components of magnetization isolated were used to estimate the vertical-axis rotations occurring during model deformation. We find that indenters pushing into deforming belts from behind form non-rotational curved outer fronts. The more internal fronts show oroclinal-type rotations of a smaller magnitude than that expected for a perfect orocline. Lateral symmetrical obstacles in the foreland colliding with forward propagating belts produce non-rotational outer curved fronts as well, whereas in between and inside the obstacles a perfect orocline forms only when the ratio between obstacles’ distance and thickness of the cover is greater than 10. Finally, when a belt collides with an obstacle in the foreland oblique to the shortening direction the outer front displays rotations opposite in sign to oroclinal-type rotations, whereas the internal fronts seem to assume an "oroclinal type" rotational pattern. Furthermore rotation is easier in laterally unconfined models, i.e. when the wedge can "escape" laterally. The results from our models may be useful when compared to paleomagnetic rotations detected in natural arcs. In these cases, our results may allow for better understanding the tectonic setting controlling the genesis of curved mountain fronts, as is the case of the Gela Nappe of Sicily we compare with some of our models.
    Description: Published
    Description: 633-654
    Description: JCR Journal
    Description: reserved
    Keywords: paleomagnetism ; tectonic rotations ; physical models ; arcuate belts ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 29
    facet.materialart.
    Unknown
    Distribution of volatile organic compounds in Sicilian groundwaters analysed by head space-solid phase micro extraction coupled with gas chromatography mass spectrometry (SPME/GC/MS) (2008)
    Elsevier
    Details
    Publication Date: 2020-12-09
    Description: This work presents the results of an assessment of the existence and concentration of 13 volatile organic compounds (VOCs) in groundwaters from 14 hydrological basins in Sicily (25,710 km2). On the basis of hydrological, hydrogeochemical and geological studies, 324 sampling points were selected. All groundwater sampled were collected twice, from October to December 2004 and from February to May 2005, and were analysed to determine the concentration and spatial distribution of the VOCs in the aquifers. The need to analyze a large number of samples in a short space of time so as to obtain quantitative analyses in trace concentration levels spurred us to create a new analytical method, both simple and sensitive, based on HS-SPME/GC/MS. The concentrations of VOCs measured in industrial and intensive agricultural unconfined aquifers were greater than those found in other aquifers. Tetrachloroethylene, chloroform, trichloroethylene and 1,2-dichloropropane were the most frequently detected VOCs. However, they exceeded the guideline values proposed by the EU in only three aquifers located near to industrial and intense agricultural areas.
    Description: Published
    Description: 3563-3577
    Description: 4.4. Scenari e mitigazione del rischio ambientale
    Description: JCR Journal
    Description: reserved
    Keywords: groundwater pollution ; VOCs ; aliphatic compounds ; groundwater monitoring ; 03. Hydrosphere::03.02. Hydrology::03.02.03. Groundwater processes
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 30
    facet.materialart.
    Unknown
    Non-Newtonian rheology of crystal-bearing magmas and implications for magma ascent dynamics (2007)
    Elsevier
    Details
    Publication Date: 2021-01-27
    Description: The eruptive dynamics of volcanic systems are largely controlled by the viscosity of deforming magma. Here we report the results of a series of high-temperature, high-pressure experiments at conditions relevant for volcanic conduits (250 MPa confining pressure and temperature between 500 °C and 900 °C) that were undertaken to investigate the rheology of magma with crystal fractions varying between 0.5 and 0.8 (50 to 80 wt.%) at different strain-rate conditions. The experiments demonstrate that the presence of crystals increases the relative viscosity (ratio between the viscosity of the mixture and the viscosity of the melt phase) of magmas and additionally induces a decrease of the relative viscosity with increasing strain-rate (shear thinning, non-Newtonian behavior). The experimental results, combined with existing data at low crystal fractions (0–0.3), were used to develop a semi-empirical parameterization that describes the variations of relative viscosity for crystal fractions between 0 and 0.8 and accounts for the complex non-Newtonian rheology of crystal-bearing magmas. The new parameterization, included into numerical models simulating the magma ascent dynamics, reveals that strain-rate-dependent rheology significantly modifies the dynamic behavior inside volcanic conduits, particularly affecting the magma fragmentation conditions.
    Description: Published
    Description: 402-419
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: partially_open
    Keywords: magma rheology ; experimental deformation ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 31
    facet.materialart.
    Unknown
    Chemical evolution of thermal waters and changes in the hydrothermal system of Papandayan volcano (West Java, Indonesia) after the November 2002 eruption (2008)
    Elsevier
    Details
    Publication Date: 2021-05-17
    Description: Papandayan is a stratovolcano situated in West Java, Indonesia. Since the last magmatic eruption in 1772,only few hydrothermal explosions have occurred. An explosive eruption occurred in November 2002 and ejected ash and altered rocks. The altered rocks show that an advanced argillic alteration took place in the hydrothermal system by interaction between acid fluids and rocks. Four zones of alteration have been defined and are limited in extension and shape along faults or across permeable structures at different levels beneath the active crater of the volcano. At the present time, the activity is centered in the northeast crater with discharge of low temperature fumaroles and acid hot springs. Two types of acid fluids are emitted in the crater of Papandayan volcano: (1) acid sulfate-chloride waters with pH between 1.6 and 4.6 and (2) acid sulfate waters with pH between 1.2 and 2.5. The water samples collected after the eruption on January 2003 reveal an increase in the SO4/Cl and Mg/Cl ratios. This evolution is likely explained by an increase in the neutralization of acid fluids and tends to show that water–rock interactions were more significant after the eruption. The evolution in the chemistry observed since 2003 is the consequence of the opening of new fractures at depth where unaltered (or less altered) volcanic rocks were in contact with the ascending acid waters. The high δ34S values (9–17‰) observed in acid sulfatechloride waters before the November 2002 eruption suggest that a significant fraction of dissolved sulfates was formed by the disproportionation of magmatic SO2. On the other hand, the low δ34S (−0.3–7‰) observed in hot spring waters sampled after the eruption suggest that the hydrothermal contribution (i.e. the surficial oxidation of hydrogen sulfide) has increased.
    Description: Published
    Description: 276-286
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: 2.4. TTC - Laboratori di geochimica dei fluidi
    Description: JCR Journal
    Description: reserved
    Keywords: Papandayan volcano ; Indonesia ; phreatic eruption ; hydrothermal system ; fluid geochemistry ; advanced argillic alteration ; gas geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 32
    facet.materialart.
    Unknown
    Stable isotope composition of Late Pleistocene-Holocene Eobania vermiculata (Müller, 1774) (Pulmonata, Stylommatophora) shells from the Central Mediterranean basin: Data from Grotta d’Oriente (Favignana, Sicily) (2012)
    Elsevier
    Details
    Publication Date: 2021-04-07
    Description: This paper presents stable isotopic results (oxygen and carbon) from both modern and Late Pleistocene-Holocene shells of the land snail Eobania vermiculata (Müller, 1774) from Favignana Island (Sicily). It aims to contribute to the understanding of climate and vegetation history of this region during formation of Upper Palaeolithic, Mesolithic and Meso-Neolithic deposits of Grotta d’Oriente (ORT). Results from both an evaporative model (FBM) and an empirical regional isotopic model (i.e. linear relation between oxygen isotopic composition of shells (δ18Os) and those of local precipitation (δ18Op)) indicate that the δ18Os values of modern specimens are mainly controlled by local temperature, relative humidity and δ18Op at the time of snail activity. Data also suggest that the modern snails are nocturnally active almost all-year round in the study area. The carbon isotopic compositions of shells (δ13Cs) of the same specimens indicate a diet prevalently (or exclusively) composed of C3 vegetation. The δ18Os values of Late Pleistocene specimens suggest that climate conditions at ∼14.2 ka cal BP were similar to the present day, in agreement with additional δ18Os records from southern Italy. By contrast, early-middle Holocene shells are notably 18O-depleted and suggest wetter conditions, possibly combined with a decrease in isotopic composition of precipitation source, compared to the present day. When compared with regional palaeoclimatic records a large-scale isotopic response to millennial-scale changes in atmospheric and hydrological conditions (e.g. enhanced rainfall) in the central-eastern Mediterranean is observed during the early-middle Holocene. The δ13Cs of Late Pleistocene and Holocene specimens are consistently higher than those of modern ones. For the Late Pleistocene, this could be reasonably explained in terms of water-stressed vegetation. On the other hand, this seems to be less valid for Holocene counterparts when the climate was wetter. Probably δ13Cs values result from the combination of distinct competing factors, involving atmospheric CO2 concentration, seasonal water budget, vegetation type-cover and other carbon sources. Results reveal coherent relationships between regional δ18Os and δ13Cs, demonstrating that Late Pleistocene-Holocene land snail shell remains from archaeological sites may provide useful snapshots of past seasonal climate conditions.
    Description: Published
    Description: 76-87
    Description: 3.7. Dinamica del clima e dell'oceano
    Description: JCR Journal
    Description: reserved
    Keywords: Landsnail ; paleoclimate ; stable isotopes ; 03. Hydrosphere::03.01. General::03.01.06. Paleoceanography and paleoclimatology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 33
    facet.materialart.
    Unknown
    A geologic contribution to the evaluation of the seismic potential of the Kahrizak fault (Tehran, Iran) (2008)
    Elsevier
    Details
    Publication Date: 2021-06-16
    Description: In this paper we present the results of preliminary geomorphic and trenching investigations along the Kahrizak fault. This fault is located south of the highly populated metropolis of Tehran and represents one of the main structures in the area containing important seismic potential. The Kahrizak fault has a very clear expression at the surface where it forms a prominent 35-km-long, 15-m-high scarp on Holocene alluvial deposits. The fault strikes N70°-80°W and dips to the north. Movement is prevalently right-lateral with the northern side of the fault up. Trench excavations exposed a sequence of weathered, massive, alluvial deposits which are dated, by means of radiometric methods, to the Holocene. In the trenches the sequence is intensely deformed by north-dipping, high- and low-angle faults within a 30-m-wide zone. On the basis of stratigraphic and structural relations, some evidence for individual Holocene earthquakes is found; however, we were not able to reconstruct the seismic history of the fault nor to evaluate the size of deformation produced by each event. Because of the possible ~10 m offset of ancient linear hydraulic artifacts (qanáts), that cross the fault, we hypothesize that the most recent event may have occurred in historical times (more recent than 5000 yr B.P.) and it may be one of those reported in this area by the current catalogues of seismicity. Based on these preliminary investigations we estimate an elapsed time between 5000 and 800 years, a maximum slip per event dmax of ~10 m, a minimum Holocene vertical slip rate of ~1 mm/yr versus a horizontal slip rate of ~3.5 mm/yr, a maximum of ~3000 years for the average recurrence time, and an expected Mw = 7.0 to 7.4. These can be considered as a first-hand reference for the activity on this fault.
    Description: Published
    Description: 187-199
    Description: 3.2. Tettonica attiva
    Description: N/A or not JCR
    Description: reserved
    Keywords: Iran ; paleoseismicity ; geomorphology ; seismic hazard assessment ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 34
    facet.materialart.
    Unknown
    High-temperature viscosity measurements of hydrous albite liquid using in-situ falling sphere viscometry at 2.5 GPa (2007)
    Elsevier
    Details
    Publication Date: 2020-10-29
    Description: In-situ falling-sphere viscometry using shadow radiography in a multianvil apparatus was conducted on a series of samples along the NaAlSi3O8–H2O join up to 2.8 wt.% H2O at the Spring-8 synchrotron radiation facility (Hyogo, Japan). This allowed us to determine viscosities normally too low to be measured at ambient pressure for hydrous silicate melts at high temperatures due to rapid devolatilization. Pressure was fixed at 2.5 GPa for all experiments allowing us to gauge the effect of chemical composition on viscosity. In particular, the series of samples allowed us to vary the melt's degree of polymerization while maintaining a constant Al to Si ratio. Our results show that, for all samples, viscosity decreases as a function of pressure between 1 atm and 2.5 GPa at 1550 °C, indicating that the pressure anomaly can still be observed as depolymerization of the melt increases from nominally 0 (dry albite liquid) to NBO/T=0.8 (assuming water speciation entirely as hydroxyl groups at experimental conditions). We also find that the magnitude of the decrease in viscosity over this pressure interval does not appear to be dependent on the amount of water in the melt (i.e., NBO/T). An explanation for this behavior might be that the molar volume, at least over this limited compositional range, is nearly constant and the effects of compression of these melts, though different in degree of polymerization, are similar.
    Description: Published
    Description: 2-9
    Description: JCR Journal
    Description: reserved
    Keywords: Viscosity ; Silicate melts ; High pressure ; 04. Solid Earth::04.01. Earth Interior::04.01.05. Rheology ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 35
    facet.materialart.
    Unknown
    Quaternary climatic control of biogenic magnetite production and eolian dust input in cores from the Mediterranean Sea (2008)
    Elsevier
    Details
    Publication Date: 2020-10-29
    Description: We report high-resolution magnetic measurements from two Mediterranean piston cores: LC07 (Sicily Strait) and LC10 (Ionian Sea). Magnetostratigraphic results and δ18O data provide age constraints for core LC07, where we investigate magnetic property variations for two age intervals (0-600 kyr and 660-1020 kyr). For core LC10, rock magnetic parameters appear to be climatically controlled and are used to derive an astronomically tuned age model for the interval between 780 and 1200 kyr. In core LC07, the dominant control on the magnetic properties appears to be glacial-interglacial variations in the concentration of biogenic magnetite. In addition, an increased contribution from high coercivity minerals (e.g. hematite and/or goethite) probably reflects an enhanced eolian input during glacial periods. Climatic control of magnetotactic bacterial populations has been previously suggested in other environments, but this is the first such report from the Mediterranean. In contrast, the rock magnetic response to Quaternary climatic variability in core LC10 seems to be better expressed by variations in the concentration of high coercivity magnetic minerals. The contrast between a dominantly detrital/eolian flux and a dominantly biogenic flux at the same time for the two Mediterranean settings might relate to the presence of an active current regime in the Sicily Strait, which might decrease delivery of an eolian component to the seafloor compared to the deep Ionian Sea.
    Description: Published
    Description: 195-209
    Description: 2.2. Laboratorio di paleomagnetismo
    Description: 3.8. Geofisica per l'ambiente
    Description: JCR Journal
    Description: reserved
    Keywords: environmental magnetism ; biogenic magnetite ; eolian dust ; glacial-interglacial cycles ; Mediterranean Sea ; 04. Solid Earth::04.05. Geomagnetism::04.05.07. Rock magnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 36
    facet.materialart.
    Unknown
    Physical properties of tuffs from a scientific borehole at Alban hills volcanic district (central Italy) (2008)
    Elsevier
    Details
    Publication Date: 2020-11-17
    Description: Recent seismic swarms and hydrothermal activity suggest that the Quaternary volcanic complex of the Alban Hills may pose a threat to the city of Rome. A 350m scientific borehole was therefore drilled into this volcanic area to elucidate its inner structure for the first time. Wire-line logs were run in the borehole in order to characterize the physical properties of the rocks and their variations with depth. In particular, a detailed sonic log was run to measure the P-wave velocity from the well-head down to 110 m. To further investigate velocity changes, we carried out laboratory measurements of P and S elastic wave velocities and fluid permeability at effective pressures up to 70 MPa during both increasing and decreasing pressure cycles on selected core samples representative of the main volcanic units. Specifically, we studied samples from two pyroclastic units representative of two classes of volcanic deposits that are representative of the whole succession: (i) a coarse-grained, well-lithified facies (Pozzolane Rosse unit), containing abundant mm-to-cm lava clasts and crystals; and (ii) a fine-grained, matrix-supported pyroclastic deposit (Tufo Pisolitico di Trigoria unit), with rare lithic lava clasts and sparse pumice. Elastic wave velocities reveal significant differences between units and indicate how, within the same lithology, the different degree of lithification and presence of clasts can affect significantly physical property values. The mean laboratory value of the Pwave velocity for Pozzolane Rosse and Tufo Pisolitico di Trigoria units is respectively of 3.75 and 3.2 km/s at an effective pressure equivalent to that at the depth at which the sonic velocity was measured. Under increasing effective pressure a profound influence on the transport properties is observed. Permeability ranges from the order of 10−18 m2 for the Pozzolane Rosse unit to the order of 10−15 m2 for the Tufo Pisolitico di Trigoria unit, in good agreement with the shallow aquifer circulating in the shallower units.
    Description: Published
    Description: 161-169
    Description: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici
    Description: JCR Journal
    Description: reserved
    Keywords: Scientific borehole ; Volcanic rocks ; Physical properties ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 37
    facet.materialart.
    Unknown
    The evolution of elastic moduli with increasing crack damage during cyclic stressing of a basalt from Mt. Etna volcano (2008)
    Elsevier
    Details
    Publication Date: 2020-11-16
    Description: Volcanic edifices, such as Mt. Etna (Italy), are commonly subject to repeated cycles of stress over time due to the combination of magma emplacement from deep reservoirs to shallow depths and superimposed tectonic stresses. Such repeated stress cycles lead to anisotropic deformation and an increase in the level of crack damage within the rocks of the edifice and hence changes to their elastic moduli, which are a key parameter for reliable modelling of deformation sources. We therefore report results of changes in elastic moduli measured during increasing amplitude cyclic stressing experiments on dry and water-saturated samples of Etna basalt. In all experiments, the Young’s modulus decreased by approximately 30% over the total sequence of loading cycles, and the Poisson’s ratio increased by a factor of approximately 3 ± 0.5. Microseismicity, in terms of acoustic emission (AE) output, was also recorded throughout each experiment. Our results demonstrate that AE output only re-commences during any loading cycle when the level of stress where AE ceased during the unloading portion of the previous cycle is exceeded; a manifestation of the Kaiser stress-memory effect. In cycles where no AE output is generated, we also observe no change in elastic moduli. This result is observed for both mechanical and thermal stressing. Our results are interpreted in relation to measurements of volcano-tectonic seismicity and deformation at Mt. Etna volcano.
    Description: Published
    Description: 153-160
    Description: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici
    Description: JCR Journal
    Description: reserved
    Keywords: rock mechanics, elastic moduli, Etna basalt ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 38
    facet.materialart.
    Unknown
    TWODEE-2: A shallow layer model for dense gas dispersion on complex topography (2008)
    Elsevier
    Details
    Publication Date: 2020-11-17
    Description: TWODEE-2 is a FORTRAN 90 code based on previous code (TWODEE). It is designed to solve the shallow water equations for fluid depth, depth-averaged horizontal velocities and depth-averaged fluid density. The shallow layer approach used by TWODEE-2 is a compromise between the complexity of CFD models and the simpler integral models. It can be used for forecasting gas dispersion near the ground and/or for hazard assessment over complex terrains. The inputs to the model are topography, terrain roughness, wind measurements from meteorological stations and gas flow rate from the ground sources. Optionally the model can be coupled with the output of a meteorological processor which generates a zero-divergence wind field incorporating terrain effects. Model outputs are gas concentration, depth-averaged velocity, averaged cloud thickness and dose. The model can be a useful tool for gas hazard assessment by evaluating where and when lethal concentrations for humans and animals can be reached.
    Description: Published
    Description: 667-674
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Description: JCR Journal
    Description: reserved
    Keywords: Dense gas transport ; Fortran code ; Gas hazard ; Computational model ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 05. General::05.01. Computational geophysics::05.01.99. General or miscellaneous ; 05. General::05.08. Risk::05.08.01. Environmental risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 39
    facet.materialart.
    Unknown
    Science Rational for MIERS/IRI Collaboration (2007)
    Elsevier
    Details
    Publication Date: 2020-12-01
    Description: In this paper, we will shortly highlight some of the aspects that COST Action 296 on Mitigation of Ionospheric Effects on Radio Systems (MIERS) and International Reference Ionosphere (IRI) have in common in an attempt to define science rationale for collaboration between these two international projects.
    Description: Published
    Description: 1621-1623
    Description: 2A. Fisica dell'alta atmosfera
    Description: JCR Journal
    Description: open
    Keywords: COST296 Action MIERS ; IRI ; ionospheric monitoring and modelling ; 01. Atmosphere::01.02. Ionosphere::01.02.99. General or miscellaneous ; 05. General::05.07. Space and Planetary sciences::05.07.02. Space weather
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 40
    facet.materialart.
    Unknown
    Magnetic fabric of Plio-Pleistocene sediments from the Crotone fore-arc basin: Insights on the recent tectonic evolution of the Calabrian Arc (Italy) (2014)
    Elsevier
    Details
    Publication Date: 2020-12-07
    Description: Low-field anisotropy of magnetic susceptibility (AMS) analyses were performed on 532 samples col-lected in 36 (mostly lower Pliocene to lower Pleistocene) marine clay sites from the Crotone basin, afore-arc basin located on top of the external Calabrian accretionary wedge. The Crotone basin formedsince mid-late Miocene under a predominant extensional tectonic regime, but it was influenced there-after by complex interactions with NW–SE left-lateral strike-faults bounding the basin, which also yieldedpost-1.2 Ma ~30◦counterclockwise block rotations. The basin is filled by continental to marine sedimentsyielding one of the thickest and best-exposed Neogene succession available worldwide. The deep-marinefacies – represented by blue-grey marly clays gave the best results, as they both preserved a clear mag-netic fabric, and provided accurate chronology based on previously published magnetostratigraphy andcalcareous plankton (i.e. foraminifers and nannofossils) biostratigraphy. Magnetic susceptibility rangeand rock magnetic analyses both indicate that AMS reflects paramagnetic clay matrix crystal arrange-ment. The fabric is predominantly oblate to triaxial, the anisotropy degree low (〈1.06), and the magneticfoliation mostly subparallel to bedding. Magnetic lineation is defined in 30 out of 36 sites (where thee12 angle is 〈35◦). By also considering local structural analysis data, we find that magnetic fabric wasgenerally acquired during the first tectonic phases occurring after sediment deposition, thus validatingits use as temporally dependent strain proxy. Although most of the magnetic lineations trend NW–SE andare orthogonal to normal faults (as observed elsewhere in Calabria), few NE–SW compressive lineationsshow that the Neogene extensional regime of the Crotone basin was punctuated by compressive episodes.Finally, compressive lineations (prolate magnetic fabric) documented along the strike-slip fault boundingthe basin to the south support the significance of Pleistocene strike-slip tectonics. Thus the Crotone basinshows a markedly different tectonics with respect to other internal and western basins of Calabria, asit yields a magnetic fabric still dominated by extensional tectonics but also revealing arc-normal short-ening episodes and recent strike-slip fault activity. The tectonics documented in the Crotone basin iscompatible with a continuous upper crustal structural reorganization occurring during the SE-migrationof the Calabria terrane above the Ionian subduction system.
    Description: Published
    Description: 67-79
    Description: 1A. Geomagnetismo e Paleomagnetismo
    Description: JCR Journal
    Description: restricted
    Keywords: Calabrian Arc, Anisotropy of magnetic susceptibility, Structural analysis, Fore-arc region ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism ; 04. Solid Earth::04.05. Geomagnetism::04.05.07. Rock magnetism ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 41
    facet.materialart.
    Unknown
    Mid-distal occurrences of the Albano Maar pyroclastic deposits and their relevance for reassessing the eruptive scenarios of the most recent activity at the Colli Albani Volcanic District, Central Italy (2007)
    Elsevier
    Details
    Publication Date: 2021-01-25
    Description: The Late Pleistocene Albano Maar hosted the most recent volcanic activity of the Colli Albani Volcanic District, represented at nearvent sections by a thick pyroclastic succession of seven units clustered in two main eruptive cycles dated at around 70–68 and 41–36 ka B.P., respectively. Recent stratigraphic investigations allowed us to recognise a pyroclastic succession comprising four eruptive units widely spread in the northeastern sectors of the Colli Albani volcano, up to 15km eastward from the Albano Maar. Integrated tephrostratigraphic, morpho-pedostratigraphic, archaeological, petrological and geochemical analyses enable us to recognise them as distal deposits of the first, third, fifth and seventh Albano Maar eruptions, enlarging significantly their previously supposed dispersion area. Further tephrostratigraphic studies in central Apennine area, allowed us to identify the Albano Maar products in Late Pleistocene deposits of several intermountain basins, extending still further the dispersion area of distal ash fallout as far as 100–120km from the vent. On the basis of the identification and the study of these previously unrecognised mid-distal Albano Maar deposits, a reappraisal of the eruptive scenarios and related energetic parameters is proposed.
    Description: Published
    Description: 160–178
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: JCR Journal
    Description: reserved
    Keywords: Colli Albani ; Albano ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 42
    facet.materialart.
    Unknown
    Temporal trends and matrix-dependent behaviors of trace elements closed to a geothermal hot-spot source (Aeolian Archipelago, Italy) (2012)
    Elsevier
    Details
    Publication Date: 2021-04-07
    Description: Degassing activity from marine shallow-water hydrothermal vents represents a natural important source of trace elements of particular ecotoxicological concern, such as Hg, Cd, Pb, and As. In 2002, on November 3rd, a submarine area of the Aeolian Archipelago (Italy) was affected by an exceptional hydrothermal activity, presumably associated to a significant trace element release. This study developed in the highest impacted area, was focused on different environmental matrices (water, sediment, primary producers, and fishes) with the aim to evaluate on a statistical basis temporal dynamics involving trace elements closed to the emission source. Results evidenced that this event produced significant changes in water column, modifying the general assessment of the chemical descriptors selected (Na, K, Mg, Ca, Cl, Br, SO4 2-, HCO3 -). Furthermore, the degassing activity represents a significant input of Hg, Cd, Pb, and As for all of the sampled matrices, being it responsible of the higher levels observed in the study area compared to controls. Concentrations measured in sediments and biota (Cystoseira compressa, Serranus cabrilla) at temporal intervals of ten months distanced, supported the occurrence of different time scale dynamics which are both element and matrix-dependent. In particular, levels of Cd and As measured in liver tissues of S. cabrilla evidenced a significant trend to increase with the time, allowing to exclude a quick recovery of the study area. Measured values in edible fishes tissues are, also, notably higher than risk limits proposed by the 2001/22/CE Directive for human consumption, so, local-based caught have to be accurately regulated to avoid the occurrence of diet over-exposure.
    Description: Published
    Description: 10-28
    Description: 1.8. Osservazioni di geofisica ambientale
    Description: N/A or not JCR
    Description: restricted
    Keywords: trace elements ; hydrothermal vents ; 03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 43
    facet.materialart.
    Unknown
    Prediction of response spectra via real-time earthquake measurements (2007)
    Elsevier
    Details
    Publication Date: 2021-06-21
    Description: The development and implementation of an earthquake early warning system (EEWS), both in regional or on-site configurations can help to mitigate the losses due to the occurrence of moderate-to-large earthquakes in densely populated and/or industrialized areas. The capability of an EEWS to provide real-time estimates of source parameters (location and magnitude) can be used to take some countermeasures during the earthquake occurrence and before the arriving of the most destructive waves at the site of interest. However, some critical issues are peculiar of EEWS and need further investigation: (1) the uncertainties on earthquake magnitude and location estimates based on the measurements of some observed quantities in the very early portion of the recorded signals; (2) the selection of the most appropriate parameter to be used to predict the ground motion amplitude both in near-and far-source ranges; (3) the use of the estimates provided by the EEWS for structural engineering and risk mitigation applications. In the present study, the issues above are discussed using the Campania–Lucania region (Southern Apennines) in Italy, as test-site area. In this region a prototype system for earthquake early warning, and more generally for seismic alert management, is under development. The system is based on a dense, wide dynamic accelerometric network deployed in the area where the moderate-to-large earthquake causative fault systems are located. The uncertainty analysis is performed through a real-time probabilistic seismic hazard analysis by using two different approaches. The first is the Bayesian approach that implicitly integrate both the time evolving estimate of earthquake parameters, the probability density functions and the variability of ground motion propagation providing the most complete information. The second is a classical point estimate approach which does not account for the probability density function of the magnitude and only uses the average of the estimates performed at each seismic station. Both the approaches are applied to two main towns located in the area of interest, Napoli and Avellino, for which a missed and false alarm analysis is presented by means of a scenario earthquake: an M 7.0 seismic event located at the centre of the seismic network. Concerning the ground motion prediction, attention is focused on the response spectra as the most appropriate function to characterize the ground motion for earthquake engineering applications of EEWS.
    Description: Published
    Description: On line First
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: reserved
    Keywords: Earthquake early-warning ; Real-time seismology ; Bayesian analysis ; Missed and false alarm ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics ; 04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 44
    facet.materialart.
    Unknown
    Crustal residence times of explosive phonolite magmas: U–Th ages of magmatic Ca-Garnets of Mt. Somma-Vesuvius (Italy) (2008)
    Elsevier
    Details
    Publication Date: 2021-06-16
    Description: Assessing the residence times of phonolite magmas in the shallow crust contributes to the understanding of explosive volcanic systems. Estimations of that by dating the residence time of a mineral in a melt was difficult in the past, because e.g. of the lack of evidence for the co-genetic character of the crystals dated. Here we present an estimate for the residence time of a phonolite magma feeding the Pomici di Mercato Plinian eruption (8890±90 cal years BP) of Mt. Somma-Vesuvius (Southern Italy), employing U–Th disequilibrium dating of unzoned Ca-rich phenocrystic magmatic garnets. Based on combined textural, geochemical, and Sr- O isotope evidence, these garnets can be identified as co-genetic with their host phonolites. Furthermore, experimental and petrological data suggest that Ca-garnets can be a liquidus phase in highly differentiated phonolite magmas of Mercato. A whole-rock–glass–garnet U–Th isochron gives a crystallisation age for the Ca-rich garnets of 14,400±1100 a (2σ). This implies a Ca-garnet residence time of 5510±1100 years (2σ) in the Mercato phonolite melt prior to eruption and provides one of the first robust estimates of how long explosive phonolite magma has resided in the shallow crust before eruption. Calculations of magma cooling rates and settling velocities of the Ca-garnets confirm that garnet-bearing phonolite can remain liquid and the garnets remain suspended in a magma chamber for as long as 5510 years before the time of eruption. Processes which may have disturbed the U–Th isotope systematic of the samples, such as assimilation, recharge or surface alteration can be ruled out.
    Description: Published
    Description: 293-301
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: 3.5. Geologia e storia dei sistemi vulcanici
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: Uranium ; Thorium ; U–Th isotopes ; Somma-Vesuvius ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 45
    facet.materialart.
    Unknown
    Cyanobacteria in Scandinavian coastal waters — A potential source for biofuels and fatty acids? (2014)
    Elsevier
    In:  EPIC3Algal Research, Elsevier, 5, pp. 42-51, ISSN: 2211-9264
    Details
    Publication Date: 2014-06-24
    Description: Since land-based biofuel production competes with conventional food production, a water-based biomass and biofuel production from cyanobacteria offers large potential. This study investigates the application potential of cyanobacteria for fuel production and by-products by mimicking nutrient depleted environmental conditions. Three Baltic cyanobacteria strains (Aphanizomenon flos-aquae, Dolichospermum lemmermannii and Nodularia spumigena) were inoculated in full nutrient levels, as well as phosphorus and nitrogen depleted medium, before being monitored for 14 days. For screening reasons, multiple parameters such as fatty acids, photosynthetic pigments including phycobilins, biovolume, photosynthetic activity, inorganic nutrients, particulate organic carbon, nitrogen and phosphorous were investigated every seven days. We observed a strong negative relationship between lipid content, growth and nutrient availability, resulting in high lipid and pigment production in combination with a limited growth rate in nutrient depleted treatments. Our results suggest that cultivation and harvest of bloom-forming cyanobacteria for fuel and by-product production are feasible in Scandinavia, but strongly depends on the desired compounds and biomass. Each cyanobacteria species originally has a species-specific chemical fingerprint that may be modified by rearing conditions and harvesting period to meet the needs of the consumer. This leads to important conclusions regarding future culturing conditions and biomass production of the desired compounds.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 46
    facet.materialart.
    Unknown
    Biological validation of physical coastal waters classification along the NE Atlantic region based on rocky macroalgae distribution (2014)
    Elsevier
    In:  EPIC3Estuarine, Coastal and Shelf Science, Elsevier, 147, pp. 103-112, ISSN: 0272-7714
    Details
    Publication Date: 2014-06-30
    Description: A methodology to classify rocky shores along the North East Atlantic (NEA) region was developed. Previously, biotypes and the variability of environmental conditions within these were recognized based on abiotic data. A biological validation was required in order to support the ecological meaning of the physical typologies obtained. A database of intertidal macroalgae species occurring in the coastal area between Norway and the South Iberian Peninsula was generated. Semi-quantitative abundance data of the most representative macroalgal taxa were collected in three levels: common, rare or absent. Ordination and classification multivariate analyses revealed a clear latitudinal gradient in the distribution of macroalgae species resulting in two distinct groups: one northern and one southern group, separated at the coast of Brittany (France). In general, the results based on biological data coincided with the results based on physical characteristics. The ecological meaning of the coastal waters classification at a broad scale shown in this work demonstrates that it can be valuable as a practical tool for conservation and management purposes.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 47
    facet.materialart.
    Unknown
    Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin (2014)
    Elsevier
    In:  EPIC3Earth and Planetary Science Letters, Elsevier, 394, pp. 99-110, ISSN: 0012-821X
    Details
    Publication Date: 2018-08-10
    Description: Neodymium and hafnium isotopes and elemental concentrations (Sm, Nd, Hf, Zr) have been measured in three water column profiles south of the Antarctic Circumpolar Current in, and to the east of the Ross Sea, in conjunction with five bottom water samples from the Amundsen Sea Embayment. Neodymium and hafnium both appear to be released from sediments in the Embayment. In the case of Nd, this is reflected in radiogenic isotope compositions (εNd up to −5.4) and highly elevated concentrations (up to 41 pmol/kg). Hafnium isotopes, on the other hand, are only very slightly altered relative to the open ocean sites, and boundary release is most prominently indicated by elevated concentrations (〉1 pmol/kg versus ∼0.7 pmol/kg). There is also a local input of both Hf and Nd at the Marie Byrd Seamounts, which leads to Nd isotope compositions as radiogenic as −3.1, and hafnium shifted to less radiogenic compositions in local bottom water. A compilation of the new data with literature data reveals a consistent view of the influence of Antarctica on the Nd isotope composition in Lower Circumpolar Deep Water (LCDW) and Antarctic Bottom Water (AABW). Sector specific Nd addition shifts AABW formed in the Atlantic sector to less radiogenic isotope compositions (average εNd = −9) relative to LCDW (average εNd = −8.4), whereas AABW in the Pacific sector is shifted to more radiogenic values (average εNd = −7). The evolution towards more radiogenic εNd with depth in LCDW in the Pacific sector is likely to reflect admixture of AABW but, in addition, is also controlled by boundary exchange with the slope as observed at the Marie Byrd Seamounts. Hafnium isotopes are relatively homogeneous in the data set, ranging between εHf = +2 and +3.8 for most samples, excluding less radiogenic compositions in deep waters close to the Marie Byrd Seamounts. The Hf isotope composition in the Pacific sector is, however, slightly less radiogenic than in the Atlantic, corresponding to an average of +3 relative to an average of +3.8. This probably reflects unradiogenic Hf inputs from Antarctica to the Pacific sector, which are vertically homogenized by reversible scavenging. The Hf isotope heterogeneity in LCDW between both sectors is likely to indicate a shorter seawater residence time for Hf than for Nd, which is consistent with the dissolved – particulate phase partitioning of both elements
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 48
    facet.materialart.
    Unknown
    Insolation and glacial–interglacial control on southwestern African hydroclimate over the past 140000 years (2014)
    Elsevier
    In:  EPIC3Earth and Planetary Science Letters, Elsevier, 398, pp. 1-10, ISSN: 0012-821X
    Details
    Publication Date: 2014-06-27
    Description: The past climate evolution of southwestern Africa is poorly understood and interpretations of past hydrological changes are sometimes The past climate evolution of southwestern Africa is poorly understood and interpretations of past hydrological changes are sometimes contradictory. Here we present a record of leaf-wax δD and δ13C taken from a marine sediment core at 23°S off the coast of Namibia to reconstruct the hydrology and C3 versus C4 vegetation of southwestern Africa over the last 140 000 years (140 ka). We find lower leaf-wax δD and higher δ13C (more C4 grasses), which we interpret to indicate wetter Southern Hemisphere (SH) summer conditions and increased seasonality, during SH insolation maxima relative to minima and during the last glacial period relative to the Holocene and the last interglacial period. Nonetheless, the dominance of C4 grasses throughout the record indicates that the wet season remained brief and that this region has remained semi-arid. Our data suggest that past precipitation increases were derived from the tropics rather than from the winter westerlies. Comparison with a record from the Congo Basin indicates that hydroclimate in southwestern Africa has evolved in antiphase with that of central Africa over the last 140 ka.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 49
    facet.materialart.
    Unknown
    The Gordian knot of mangrove conservation: Disentangling the role of scale, services and benefits (2014)
    Elsevier
    In:  EPIC3Global Environmental Change, Elsevier, 28, pp. 120-128, ISSN: 0959-3780
    Details
    Publication Date: 2016-10-07
    Description: Mangrove forests are among the most threatened tropical ecosystems. Their role as providers of important ecosystem services such as coastal protection, carbon storage and nursery habitats for economically important species is increasingly acknowledged. But mangrove destruction continues, and we might have to face the prospect of a world deprived of the services offered by mangrove ecosystems. Mangrove transformation and destruction is often caused by mismatches in mangrove system management. These root in interests that focus on selected ecosystem services only, but also result from a problem of fit between the spatial scales at which ecosystem services are provided, and those at which their benefits are realized. We argue that a combination of the ecosystem services concept with a careful approach to the issue of scales will help to overcome these problems and improve the management of mangrove systems. Drawing on two case studies from Indonesia and Brazil, we illustrate the relevance of our findings for different ecosystem services.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 50
    facet.materialart.
    Unknown
    Impact of recirculation on the East Greenland Current in Fram Strait: Results from moored current meter measurements between 1997 and 2009 (2014)
    Elsevier
    In:  EPIC3Deep Sea Research Part I: Oceanographic Research Papers, Elsevier, 92, pp. 26-40, ISSN: 0967-0637
    Details
    Publication Date: 2014-09-09
    Description: Transports of total volume and water masses obtained from a mooring array in the East Greenland Current (EGC) in Fram Strait are presented for the period 1997–2009. The array in the EGC was moved along isobaths from 79°N to 78°50′N78°50′N in 2002 to line up with moorings in the eastern Fram Strait. Analysis of the time series at the two latitudes shows that associated with the southward move, the annual mean volume transport of the EGC increased from 5.8±1.8 Sv to 8.7±2.5 Sv, mostly related with an increase in barotropic flow. This suggests a recirculation of close to 3 Sv at 78°50′N78°50′N as a consequence of the large-scale wind-driven cyclonic gyre in the Nordic Seas. In addition, the volume transport at 78°50′N78°50′N showed a clear seasonal cycle which was absent at 79°N. Estimates of the wind-driven Sverdrup transport at two different latitudes show that the difference in total volume transport and seasonality can largely be explained by the wind-stress curl. However, weak transport in 2003 was only partially related with weak Sverdrup transport and coincided also with anomalously weak northerly winds. The stronger recirculation at 78°50′N78°50′N has also consequences for the observed Atlantic Water: there is significantly more Atlantic derived water present at the southerly latitude. In addition, the warm anomaly in Fram Strait between 2005 and 2007 doubled the amount of Recirculated Atlantic Water temporarily. Finally, we estimate that close to 2.7 Sv, or 50%, of Atlantic derived water recirculates in Fram Strait.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 51
    facet.materialart.
    Unknown
    Biome distribution over the last 22,000 yr in China (2014)
    Elsevier
    In:  EPIC3Palaeogeography, Palaeoclimatology, Palaeoecology, Elsevier, 409, pp. 33-47, ISSN: 0031-0182
    Details
    Publication Date: 2019-08-23
    Description: Patterns of past vegetation changes over time and space can help facilitate better understanding of the interactions among climate, ecosystem, and human impact. Biome changes in China over the last 22,000 yr (calibrated radiocarbon date, a BP) were numerically reconstructed by using a standard approach of pollen-plant functional type-biome assignment (biomization). The biomization procedure involves pollen data from 2434 surface sites and 228 fossil sites with a high quality of pollen count and 14C dating, 51 natural and three anthropogenic plant functional types (PFTs), as well as 19 natural and one anthropogenic biome. Surface pollen-based reconstruction of modern natural biome patterns is in good agreement (74.4%) with actual vegetation distribution in China. However, modern large-scale anthropogenic biome reconstruction has not been successful based on the current setup of three anthropogenic PFTs (plantation, secondary, and disturbed PFT) because of the limitation of non-species level pollen identification and the difficulty in the clear assignment of disturbed PFTs. The non-anthropogenic biome distributions of 44 time slices at 500-year intervals show large-scale discrepant and changed vegetation patterns from the last glacial maximum (LGM) to the Holocene throughout China. From 22 ka BP to 19 ka BP, temperate grassland, xerophytic shrubland, and desert dominated northern China,whereas cold or cool forests flourished in central China.Warm–temperate evergreen forests were restricted to far southern China, and tropical forestswere absent. During 18.5 ka BP to 12 ka BP, cold, cool, and dry biomes extended to someparts of northern,western, and eastern China.Warm–temperate evergreen andmixed forests gradually expanded to occupy thewhole of southern China. A slight northward shift of forest biomes occurred from15 ka BP to 12 ka BP. During 11.5 ka BP to 9 ka BP, temperate grassland and shrubland gradually stretched to northern and western China. Cold and cool forestswidely expanded into northern and central China, aswell as in the northern margin of South China along with temperate deciduous forest. Since the early mid-Holocene (approximately 8.5 ka BP to 5.5 ka BP), all forest biomes shifted northward at the expense of herbaceous and shrubby biomes. Simultaneously, cold and cool forest biomes occupied the marginal areas of the Tibetan Plateau and the high mountains in western China. During the middle to late Holocene, from 5 ka to the present, temperate grassland and xerophytic shrubland expanded to the south and east, whereas temperate deciduous forests slightly shifted southward. After 3 ka BP, forest biomes were absent in western China and on the Tibetan plateau surface. Dramatic biome shifts from theLGM to the Holocene were observed in the forest-grassland ecotone and transitional zones between temperate and subtropical climates, between subtropical and tropical regions, and in the mountainous margins of the eastern Tibetan Plateau. Evidence showed more human disturbances during the late Holocene. More pollen records and historical documents are therefore further needed to understand fully the human disturbance-induced large-scale forest changes. In addition, more classifications of anthropogenic biome or land cover, more distinct assignment of pollen taxa to anthropogenic PFTs, and more effective numerical and/or mechanistic techniques in building large-scale human disturbances are required.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 52
    facet.materialart.
    Unknown
    Dissolved methane concentration and flux in the coastal zone of the Southern California Bight-Mexican sector: Possible influence of wastewater (2014)
    Elsevier
    In:  EPIC3Estuarine, Coastal and Shelf Science, Elsevier, 144, pp. 65-74, ISSN: 0272-7714
    Details
    Publication Date: 2014-07-14
    Description: We measured dissolved methane concentrations ([CH4]) in the coastal zone of the Southern California Bight-Mexican sector (SCBMex) during two cruises: S1 in the USA–Mexico Border Area (BA) during a short rainstorm and S2 in the entire SCBMex during a drier period a few days later. High spatial variability in surface mixed layer (ML) [CH4] was observed, ranging from 2.2 nmol L−1 to 17.8 nmol L−1. ML-[CH4] was supersaturated at all BA stations during both cruises. The highest [CH4] was 72.4 nmol L−1 (2819 % supersaturated) measured at 10 m depth during S2, about 3 km southwest of the discharge point of the South Bay Ocean Outfall (SBOO). Our results show an apparent connection between wastewater treatment discharges and [CH4]. Application of a sewer CH4 production model suggests that the SBOO may be a large source of CH4 to the BA and points to the need to consider point sources in developing coastal marine CH4 budgets for highly populated areas. Based on our data, the SCBMex appears to be a relatively strong source of CH4 to the atmosphere compared to other Pacific Basin areas. The average BA sea-to-air CH4 flux (F) during S1 was (15.5 ± 8.6) × 10−2 nmol m−2 s−1, about 1.5 times higher than F during S2, which had a flux of (9.5 ± 6.9) × 10−2 nmol m−2 s−1 mainly due to the higher wind speed during S1.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 53
    facet.materialart.
    Unknown
    Development of the Western Boundary Undercurrent at Eirik Drift related to changing climate since the early Miocene (2014)
    Elsevier
    In:  EPIC3Deep Sea Research I: Oceanographic Research Papers, Elsevier, 93, pp. 21-34, ISSN: 0967-0637
    Details
    Publication Date: 2019-07-16
    Description: Eirik Drift lies on the slope south of Greenland, where it has been formed under the influence of the Western Boundary Undercurrent (WBUC) closely downstream of its origin in the deep-water formation centres of the Nordic Seas. Therefore, the sediment record at Eirik Drift documents modifications in pathways and intensity of the WBUC. These modifications reflect alterations in deep-water formation in the Nordic Seas and are therefore coupled with climate changes. Based on the seismostratigraphic analysis of sedimentary architecture identified in a set of high-resolution seismic reflection data, we have reconstructed the palaeocirculation of the WBUC at Eirik Drift since the early Miocene. We revealed a strong WBUC during warm climate conditions, and in phases of climate cooling with enhanced sea-ice extent we interpreted weak WBUC influence. We suggest a southward shift of the deep-water formation regions along with a shift of the deep current system during the cool phases. This shift implies that the main North Atlantic deep-water route affected Eirik Drift only during warm phases and that during cool phases weak branches of the circulation system flowed over Eirik Drift.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 54
    facet.materialart.
    Unknown
    The fate of microplastics in the marine isopod Idotea emarginata (2014)
    American Chemical Society
    In:  EPIC3Environmental Science and Technology, American Chemical Society, 48, pp. 13451-13458, ISSN: 0013-936X
    Details
    Publication Date: 2014-11-21
    Description: Plastic pollution is an emerging global threat for marine wildlife. Many species of birds, reptiles and fishes are directly impaired by plastics as they can get entangled in ropes and drown or they can ingest plastic fragments which, in turn, may clog their stomachs and guts. Microplastics of less than 1 mm can be ingested by small invertebrates but their fate in the digestive organs and their effects on the animals are yet not well understood. We embedded fluorescent microplastics in artificial agarose-based food and offered the food to marine isopods, Idotea emarginata. The isopods did not distinguish between food with and food without microplastics. Upon ingestion, the microplastics were present in the stomach and in the gut but not in the tubules of the midgut gland which is the principal organ of enzyme-secretion and nutrient resorption. The feces contained the same concentration of micro-plastics as the food which indicates that no accumulation of microplastics happens during the gut passage. Long-term bioassays of six weeks showed no distinct effects of continu¬ous micro-plastic consumption on mortality, growth, and intermolt duration. I. emarginata are able to prevent intrusion of particles even smaller than 1 µm into the midgut gland which is facilitated by the complex structure of the stomach including a fine filter system. It separates the midgut gland tubules from the stomach and allows only the passage of fluids and chyme. Our results indicate that micro¬plastics, as administered in the experi¬ments, do not clog the digestive organs of isopods and do not have adverse effects on their life history parameters.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 55
    facet.materialart.
    Unknown
    The Indian Ocean Zonal Mode over the past millennium in observed and modeled precipitation isotopes (2014)
    Elsevier
    In:  EPIC3Quaternary Science Reviews, Elsevier, 103, pp. 1-18, ISSN: 0277-3791
    Details
    Publication Date: 2014-10-17
    Description: The Indian Ocean Zonal Mode (IOZM) has gained considerable attention in the past decade due to its role in causing widespread flooding and droughts in the continents and islands surrounding the Indian Ocean. The IOZM has also been observed to vary on a low-frequency (multi-decadal) basis, making its behavior important to understand both for mid-range 21st century climate prediction and for paleoclimate studies. Despite efforts to reconstruct the IOZM using corals and other high-resolution proxies, nonstationarities in the response of paleoclimate proxies to the IOZM have also been noted, raising the possibility that the IOZM may be difficult to reconstruct or to predict in the long-term. It is therefore critical to assess the low-frequency component of the IOZM in observed, modeled, and paleoclimate data from the Indian Ocean region in order to identify nonstationary behavior and to assess its role in low-frequency climate variations. We present an analysis of low-frequency and nonstationary behavior in the IOZM on multi-decadal to centennial timescales using a combination of modeled, observed, and proxy reconstructions of δ18O/δDprecip. In order to assess multiple timescales of low-frequency variability, we focus on two key time periods: the historical period (1870–2003), and the past millennium (1000 C.E.-present). We find significant nonstationarities in the relationships between the IOZM, precipitation amount, and δ18Oprecip/δDprecip during the historical period. These relationships vary on a multi-decadal basis in our model and in observed/reanalysis datasets. Air-sea interactions in the Indo-Pacific Warm Pool and teleconnections to the Pacific Ocean, as well as the phase of the IOZM itself, may contribute to this nonstationary behavior. We examine the potential ramifications of nonstationary IOZM behavior using a synthesis of spatially distributed proxy archives of δ18Oprecip/δDprecip from both sides of the IOZM region spanning the past millennium. Our findings indicate that during the past millennium, a strong IOZM-like connection exists in the proxy data network, with anti-correlation between East Africa and Indonesia. However, the links are spatially limited and in some cases timescale-dependent. Nonlinear behaviors in these links suggest that the IOZM may be difficult to detect on a consistent basis in proxy records from the past millennium. Based on our modeling results, the inconsistent links in the IOZM proxy network may arise from temporally and spatially variable relationships between the IOZM, precipitation, and δ18Oprecip/δDprecip. We conclude that the IOZM's potential to influence the climate of the Indian Ocean region is inconsistently reflected in proxy data, and that due to the changing strength of the IOZM/δ18Oprecip/δDprecip relationship, its spatial “footprint” may be restricted on multi-decadal to multi-centennial timescales.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 56
    facet.materialart.
    Unknown
    On the difficulty of modeling Circumpolar Deep Water intrusions onto the Amundsen Sea continental shelf (2014)
    Elsevier
    In:  EPIC3Ocean Modelling, Elsevier, 84, pp. 26-34, ISSN: 1463-5003
    Details
    Publication Date: 2014-11-11
    Description: In the Amundsen Sea, warm Circumpolar Deep Water (CDW) intrudes onto the continental shelf and flows into the ice shelf cavities of the West Antarctic Ice Sheet, resulting in high basal melt rates. However, none of the high resolution global models resolving all the small ice shelves around Antarctica can reproduce a realistic CDW flow onto the Amundsen Sea continental shelf, and previous studies show simulated bottom potential temperature at the Pine Island Ice Shelf front of about −1.8 °C. In this study, using the Finite-Element Sea ice–ice shelf-Ocean Model (FESOM), we reproduce warm CDW intrusions onto the Amundsen Sea continental shelf and realistic melt rates of the ice shelves in West Antarctica. To investigate the importance of horizontal resolution, forcing, horizontal diffusivity, and the effect of grounded icebergs, eight sensitivity experiments are conducted. To simulate the CDW intrusion realistically, a horizontal resolution of about 5 km or smaller is required. The choice of forcing is also important and the cold bias in the NCEP/NCAR reanalysis over the eastern Amundsen Sea prevents warm CDW from intruding onto the continental shelf. On the other hand, the CDW intrusion is not highly sensitive to the strength of horizontal diffusion. The effect of grounded icebergs located off Bear Peninsula is minor, but may act as a buffer to an anomalously cold year.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 57
    facet.materialart.
    Unknown
    Uranium-Thorium Decay Series in the Oceans: Overview (2014)
    Elsevier
    In:  EPIC3Earth Systems and Environmental Sciences, (Reference Module in Earth Systems and Environmental Sciences), Amsterdam, Elsevier, 16 p., pp. 1-16, ISBN: 978-0-12-409548-9
    Details
    Publication Date: 2014-05-19
    Description: Natural radioactivity provides tracers in a wide range of characteristic timescales and reactivities, which can be used as tools to study the rate of reaction and transport processes in the ocean. Apart from cosmogenic nuclides and the long-lived radioisotope K-40, the natural radioactivity in the ocean is primarily derived from the decay series of three radionuclides that were produced in the period of nucleosynthesis preceding the birth of our solar system: Uranium-238, Thorium-232, and Uranium-235 (a fourth series, including Uranium-233, has already decayed away). The remaining activity of these so-called primordial nuclides in the Earth's crust, and the range of half-lives and reactivities of the elements in their decay schemes, control the present distribution of U-series nuclides in the ocean
    Repository Name: EPIC Alfred Wegener Institut
    Type: Inbook , peerRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 58
    facet.materialart.
    Unknown
    A 3D shear-wave velocity model of the upper mantle beneath China and the surrounding areas (2014)
    Elsevier
    In:  EPIC3Tectonophysics, Elsevier, 633, pp. 193-210, ISSN: 0040-1951
    Details
    Publication Date: 2014-12-02
    Description: We present a three-dimensional model of shear wave velocity for the upper mantle of China and the surrounding region by analyzing 50,338 vertical component multi-mode Rayleigh wave seismograms, recorded at 144 permanent and more than 300 temporary broadband stations in and around China. The procedure involves combination of 1-D path average models obtained by modeling each Rayleigh waveform up to the 4th higher mode in a tomographic inversion scheme. The dense station network and the use of multi-mode analysis help to achieve a lateral resolution of a few hundred kilometers down to 400 km depth. The seismic lithosphere, as it is defined by the crust and the high velocity mantle lid, is to the first order thin in east China and thick in the west, with a high velocity lid extending down to about 200 km depth beneath much of the Tibet–Pamir plateau. Beneath India, the thickness of the seismic lithosphere gradually increases from ~ 100 km in south India to more than 150 km in north India, where it underthrusts the Tibetan plateau to approximately the Jinsha River Suture. High velocity lid extending down to 100–150 km depth is also observed in the Tarim basin, Sichuan basin and Ordos block. In the eastern part of the North China craton the seismic lithosphere is probably close to or thinner than 70 km. Adjacent to these areas, the high velocity lid in the eastern Yangtze craton and South China fold system extends down to 70–80 km depth. A large-scale subhorizontal high velocity body is observed at depths of 150–350 km beneath the entire east China cratonic areas. This high velocity body might be the remnant of a delamination process which resulted in the decratonization of the North China and the Yangtze cratons.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 59
    facet.materialart.
    Unknown
    Anomalous South Pacific lithosphere dynamics derived from new total sediment thickness estimates off the West Antarctic margin (2014)
    Elsevier
    In:  EPIC3Global and Planetary Change, Elsevier, 123(Part A), pp. 139-149, ISSN: 0921-8181
    Details
    Publication Date: 2014-12-17
    Description: Paleotopographic models of the West Antarctic margin, which are essential for robust simulations of paleoclimate scenarios, lack information on sediment thickness and geodynamic conditions, resulting in large uncertainties. A new total sediment thickness grid spanning the Ross Sea–Amundsen Sea–Bellingshausen Sea basins is presented and is based on all the available seismic reflection, borehole, and gravity modeling data offshore West Antarctica. This grid was combined with NGDC's global 5 arc minute grid of ocean sediment thickness (Whittaker et al., 2013) and extends the NGDC grid further to the south. Sediment thickness along the West Antarctic margin tends to be 3–4 km larger than previously assumed. The sediment volume in the Bellingshausen, Amundsen, and Ross Sea basins amounts to 3.61, 3.58, and 2.78 million km3, respectively. The residual basement topography of the South Pacific has been revised and the new data show an asymmetric trend over the Pacific–Antarctic Ridge. Values are anomalously high south of the spreading ridge and in the Ross Sea area, where the topography seems to be affected by persistent mantle processes. In contrast, the basement topography offshore Marie Byrd Land cannot be attributed to dynamic topography, but rather to crustal thickening due to intraplate volcanism. Present-day dynamic topography models disagree with the presented revised basement topography of the South Pacific, rendering paleotopographic reconstructions with such a limited dataset still fairly uncertain.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 60
    facet.materialart.
    Unknown
    An advanced video-based system for monitoring active volcanoes (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Video surveillance systems are consolidated techniques for monitoring eruptive phenomena in volcanic areas. Along with these systems, which use standard video cameras, people working in this field sometimes make use of infrared cameras providing useful information about the thermal evolution of eruptions. Real-time analysis of the acquired frames is required, along with image storing, to analyze and classify the activity of volcanoes. Human effort and large storing capabilities are hence required to perform monitoring tasks. In this paper we present a new strategy aimed at improving the performance of video surveillance systems in terms of human-independent image processing and storing optimization. The proposed methodology is based on real-time thermo-graphic analysis of the area considered. The analysis is performed by processing images acquired with an IR camera and extracting information about meaningful volcanic events. Two software tools were developed. The first provides information about the activity being monitored and automatically adapts the image storing rate. The second tool automatically produces useful information about the eruptive activity encompassed by a selected frame sequence. The software developed includes a suitable user interface allowing for convenient management of the acquired images and easy access to information about the volcanic activity monitored.
    Description: Published
    Description: 85-91
    Description: reserved
    Keywords: Volcano monitoring ; Image processing ; Smart storing rate ; Eruption data ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 483034 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 61
    facet.materialart.
    Unknown
    The 2004-05 Etna eruption: implications for flank deformation and structural behaviour of the volcano (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The development of the 2004–2005 eruption at Etna (Italy) is investigated by means of field surveys to define the current structural state of the volcano. In 2004–2005, a fracture swarm, associated with three effusive vents, propagated downslope from the SE summit crater towards the SE. Such a scenario is commonly observed at Etna, as a pressure increase within the central conduits induces the lateral propagation of most of the dikes downslope. Nevertheless, some unusual features of this eruption (slower propagation of fractures, lack of explosive activity and seismicity, oblique shear along the fractures) suggest a more complex triggering mechanism. A detailed review of the recent activity at Etna enables us to better define this possible mechanism. In fact, the NW–SE-trending fractures formed in 2004–2005 constitute the southeastern continuation of a N–S-trending fracture system which started to develop in early 1998 to the east of the summit craters. The overall 1998–2005 deformation pattern therefore forms an arcuate feature, whose geometry and kinematics are consistent with the head of a shallow flank deformation on the E summit of Etna. Similar deformation patterns have also been observed in analogue models of deforming volcanic cones. In this framework, the 2004–2005 eruption was possibly induced by a dike resulting from the intersection of this incipient fracture system with the SE Crater. A significant acceleration of this flank deformation may be induced by any magmatic involvement. The central conduit of the volcano is presently open, constantly buffering any increase in magmatic pressure and any hazardous consequence can be expected to be limited. A more hazardous scenario may be considered with a partial or total closing of the central conduit. In this case, magmatic overpressure within the central conduit may enhance the collapse of the upper eastern flank, triggering an explosive eruption associated with a landslide reaching the eastern lower slope of the volcano.
    Description: Published
    Description: 195–206
    Description: reserved
    Keywords: eruption triggering ; volcano-tectonics ; fracture fields ; flank spreading ; Mt. Etna ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 2594507 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 62
    facet.materialart.
    Unknown
    A new computational approach to reduce the signal from continuously recording gravimeters for the effect of atmospheric temperature (2007)
    Elsevier
    Details
    Publication Date: 2017-04-03
    Description: The experience of several authors has shown that continuous measurements of the gravity field, accomplished through spring devices, are strongly affected by changes of the ambient temperature. The apparent, temperature-driven, gravity changes can be up to one order of magnitude higher than the expected changes of the gravity field. Since these effects are frequency-dependent and instrument-related, they must be removed through non-linear techniques and in a case-by-case fashion. Past studies have demonstrated the effectiveness of a Neuro-Fuzzy algorithm as a tool to reduce continuous gravity sequences for the effect of external temperature changes. In the present work, an upgraded version of this previously employed algorithm is tested against the signal from a gravimeter, which was installed in two different sites over consecutive 96-day and 163-day periods. The better performance of the new algorithm with respect to the previous one is proven. Besides, inferences about the site and/or seasonal dependence of the model structure are reported.
    Description: Published
    Description: 247–256
    Description: reserved
    Keywords: Gravimeters ; Exogenous parameter compensantion ; Neuro-Fuzzy algorithm ; Site effects ; 04. Solid Earth::04.03. Geodesy::04.03.05. Gravity variations ; 05. General::05.01. Computational geophysics::05.01.01. Data processing
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 1253604 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 63
    facet.materialart.
    Unknown
    Surface deformation analysis in the Ischia Island (Italy) based on spaceborne radar interferometry (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The island of Ischia, located at the northwestern end of the Gulf of Napoli (Italy), is a volcanic area that is historically active (the Arso eruption, in 1302 and the Casamicciola earthquake, in 1883) and has diffuse hydrothermal phenomena. We present in this work a study of the surface deformation occurring in the island, which is based on applying the Differential Synthetic Aperture Radar Interferometry (DInSAR) algorithm referred to as Small BAseline Subset (SBAS) technique. This study is focused on the 1992–2003 time interval and SAR data acquired by the European Remote Sensing (ERS) satellites from ascending and descending orbits have been used, thus allowing us to discriminate the vertical and east–west components of the displacements. A validation of the DInSAR results has been carried out first by comparing the vertical deformations estimated from the SAR data with those measured from the spirit leveling network that is present in the area. In particular, we computed the difference between the mean vertical deformation velocities estimated from the SAR and the corresponding geodetic measurements along three main leveling lines; the maximum value of the root mean square difference is of about 1 mm/yr. The final discussion is dedicated to the interpretation of the detected displacements, benefiting from the overall information extracted from the ascending and descending DInSAR measurements. In particular, DInSAR data relative to the vertical deformation component show that the present-day subsidence of Ischia mainly develops in areas characterized by active landsliding and along faults; moreover, the deflation of the island, which is recorded by the horizontal displacement component, is probably related to the de-pressurization of the hydrothermal system.
    Description: Published
    Description: 399-416
    Description: reserved
    Keywords: SAR interferometry ; SBAS technique ; leveling survey ; hazard ; hydrothermal systems ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 1346550 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 64
    facet.materialart.
    Unknown
    Crustal contamination and crystal entrapment during polybaric magma evolution at Mt.Somma-Vesuvius volcano, Italy: Geochemical and Sr isotope evidence (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: New major and trace element analyses and Sr-isotope determinations of rocks from Mt. Somma–Vesuvius volcano produced from 25 ky BP to 1944 AD are part of an extensive database documenting the geochemical evolution of this classic region. Volcanic rocks include silica undersaturated, potassic and ultrapotassic lavas and tephras characterized by variable mineralogy and different crystal abundance, as well as by wide ranges of trace element contents and a wide span of initial Sr-isotopic compositions. Both the degree of undersaturation in silica and the crystal content increase through time, being higher in rocks produced after the eruption at 472 AD (Pollena eruption). Compositional variations have been generally thought to reflect contributions from diverse types of mantle and crust. Magma mixing is commonly invoked as a fundamental process affecting the magmas, in addition to crystal fractionation. Our assessment of geochemical and Srisotopic data indicates that compositional variability also reflects the influence of crustal contamination during magma evolution during upward migration to shallow crustal levels and/or by entrapment of crystal mush generated during previous magma storage in the crust. Using a variant of the assimilation fractional crystallization model (Energy Conservation– Assimilation Fractional Crystallization; [Spera and Bohrson, 2001. Energy-constrained open-system magmatic processes I: General model and energy-constrained assimilation and fractional crystallization (EC–AFC) formulation. J. Petrol. 999– 1018]; [Bohrson, W.A. and Spera, F.J., 2001. Energy-constrained open-system magmatic process II: application of energyconstrained assimilation–fractional crystallization (EC–AFC) model to magmatic systems. J. Petrol. 1019–1041]) we estimated the contributions from the crust and suggest that contamination by carbonate rocks that underlie the volcano (2 km down to 9–10 km) is a fundamental process controlling magma compositions at Mt. Somma–Vesuvius in the last 8 ky BP. Contamination in the mid- to upper crust occurred repeatedly, after the magma chamber waxed with influx of new mantle- and crustal-derived magmas and fluids, and waned as a result of magma withdrawal and production of large and energetic plinian and subplinian eruptions.
    Description: Published
    Description: 303– 329
    Description: reserved
    Keywords: Mt. Somma–Vesuvius volcano ; Sr isotopes ; Geochemistry ; Crustal contamination ; Mantle source ; Phenocryst entrapment ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 879803 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 65
    facet.materialart.
    Unknown
    Slab detachment beneath eastern Anatolia: A possible cause for the formation of the North Anatolian fault (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: In this paper, we discuss the possibility that the North Anatolian fault (NAF) results from the deep deformation of the slab beneath the Bitlis–Hellenic subduction zone. We described the tectonic evolution of the Anatolia–Aegean area in three main steps, before, during and after the formation of the NAF. We remark that the tectonic conditions that are assumed to have triggered the formation of the NAF, i.e. collision to the east and extension to the west, was already achieved before the onset of that strike-slip fault system. We also highlight that the formation of the NAF was accompanied by the uplift of the Turkish–Iranian plateau and by a surge of volcanism in the eastern Anatolia collisional area and probably by the acceleration of the Aegean trench retreat. We show tomographic images from global P-wave model of Piromallo and Morelli [C. Piromallo, A. Morelli, P wave tomography of the mantle under the Alpine–Mediterranean area, J. Geophys. Res. 108 (2003) doi: 10.1029/2002JB001757.] showing that the slab beneath the Bitlis collisional belt is not continuous and that its possible rupture pursues to the west at least up to Cyprus and possibly up to the eastern end of the Hellenic trench. All these observations suggest that the plate tectonic re-organization occurred in the Late Miocene–Early Pliocene in the region results from slab break-off in the Bitlis area and from its lateral propagation to the West. This idea is tested in analogue laboratory experiments, which confirm that the break of the slab under the collisional belt may trigger, (1) the acceleration of slab retreat to the west due to the increase in slab pull force, (2) the indentation of the continent in the collisional area and (3) produce the conditions that permit the lateral escape of material towards the west and the formation of the NAF.
    Description: Published
    Description: 85-97
    Description: JCR Journal
    Description: reserved
    Keywords: Mediterranean ; subduction ; collision ; analogue experiments ; seismic tomography ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 66
    facet.materialart.
    Unknown
    Geomorphological evidence of fast Holocene coastal uplift at the western termination of the Corinth Rift (Greece): constraints on minimum Holocene uplift rate and potential paleoseismological significance (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The westernmost part of the Gulf of Corinth (Greece) is an area of very fast extension (~15 mm/yr according to geodetic measurements) and active normal faulting, accompanied by intense coastal uplift and high seismicity. This study presents geomorphic and biological evidence of Holocene coastal uplift at the western extremity of the Gulf, where such evidence was previously unknown. Narrow shore platforms (benches) and rare notches occur mainly on Holocene littoral conglomerates of uplifting small fan deltas. They are perhaps the only primary paleoseismic evidence likely to provide information on earthquake recurrence at coastal faults in the specific part of the Rift system, whereas dated marine fauna can provide constraints on average Holocene coastal uplift rate. The types of geomorphic and biological evidence identified are not ideal, and there are limitations and pitfalls involved in their evaluation. In a first approach, 5 uplifted paleoshorelines may be indentified, at 0.4- 0.7, 1.0-1.3, 1.4-1.7, 2.0-2.3 and 2.8-3.4 m a.m.s.l. They probably formed after 1728 or 2250 Cal. B.P. (depending on the marine reservoir correction used in the calibration of measured radiocarbon ages). A most conservative estimate for the average coastal uplift rate during the Late Holocene is 1.6 or 1.9 mm/yr minimum (with different amounts of reservoir correction). Part of the obtained radiocarbon ages of Lithophaga sp. allows for much higher Holocene uplift rates, of the order of 3-4 mm/yr, which cannot be discarded given that similar figures exist in the bibliography on Holocene and Pleistocene uplift at neighbouring areas. They should best be cross-checked by further studies though. That the identified paleoshoreline record corresponds to episodes of coastal uplift only, cannot be demonstrated beyond all doubt by independent evidence, but it appears the most likely interpretation, given the geological and active-tectonic context and, what is known about eustatic sea-level fluctuations in the Mediterranean. Proving that the documented uplifts were abrupt (i.e., arguably coseismic), is equally difficult, but reasonably expected and rather probable. Five earthquakes in the last ca. 2000 yrs on the coastal fault zone responsible for the uplift, compare well with historical seismicity and the results of recent on-fault paleoseismological studies at the nearby Eliki fault zone. Exact amounts of coseismic uplift cannot be determined precisely, unless the rate of uniform ("regional") non-seismic uplift of Northern Peloponnesus at the specific part of the Corinth Rift is somehow constrained.
    Description: EU project 3HAZ-Corinth
    Description: Published
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: open
    Keywords: Holocene Shorelines ; Coastal tectonics ; Paleoseismology ; Uplift ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 67
    facet.materialart.
    Unknown
    Magma dynamics at mid-ocean ridges by noble gas kinetic fractionation: Assessment of magmatic ascent rates (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Despite its impact in understanding oceanic crust formation and eruptive styles of related volcanism, magma dynamics at midocean ridges are poorly known. Here, we propose a new method to assess ascent rates of mid-ocean ridge basalt (MORB) magmas, as well as their pre- and sin-eruptive dynamics. It is based on the idea that a rising magma can reach a variable degree of both CO2 supersaturation in melt and kinetic fractionation among noble gases in vesicles in relation to its ascent rate through the crust. To quantify the relationship, we have used a model of multicomponent bubble growth in MORB melts, developed by extending the single-component model of Proussevitch and Sahagian [A.A. Proussevitch, D.L. Sahagian, Dynamics and energetics of bubble growth in magmas: analytical formulation and numerical modeling, J. Geophys. Res. 103 (1998), 18223–18251.] to CO2–He–Ar gas mixtures. After proper parameterization, we have applied it to published suites of data having the required features (glasses from Pito Seamount and mid-Atlantic ridges). Our results highlight that the investigated MORB magmas display very different ranges of ascent rates: slow rises of popping rock forming-magmas that cross the crust (0.01–0.5 m/s), slightly faster rates of energetic effusions (0.1–1 m/s), up to rates of 1–10 m/s which fall on the edge between lava effusion and Hawaiian activity. Inside a single plumbing system, very dissimilar magma dynamics highlight the large differences in compressive stress of the oceanic crust on a small scale. Constraints on how the systems of ridges work, as well as the characteristics of the magmatic source, can also be obtained. Our model shows how measurements of both the dissolved gas concentration in melt and the volatile composition of vesicles in the same sample are crucial in recognizing the kinetic effects and definitively assessing magma dynamics. An effort should be made to correctly set the studied samples in the sequence of volcanic submarine deposits where they are collected. Enhanced knowledge of a number of physical properties of gas-bearing MOR magmas is also required, mainly noble gas diffusivities, to describe multicomponent bubble growth at a higher confidence level.
    Description: Published
    Description: 138-158
    Description: JCR Journal
    Description: reserved
    Keywords: Bubble growth; ; MORB; ; Noble gas; ; Kinetic fractionation; ; Modeling ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 68
    facet.materialart.
    Unknown
    Viscosity and glass transition temperature of hydrous float glass (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Viscosity of water-bearing float glass (0.03–4.87 wt% H2O) was measured in the temperature range of 573–1523 K and pressure range of 50–500 MPa using a parallel plate viscometer in the high viscosity range and the falling sphere method in the low viscosity range. Melt viscosity depends strongly on temperature and water content, but pressure up to 500 MPa has only minor influence. Consistent with previous studies on aluminosilicate compositions we found that the effect of dissolved water is most pronounced at low water content, but it is still noticeable at high water content. A new model for the calculation of the viscosities as a function of temperature and water content is proposed which describes the experimental data with a standard deviation of 0.22 log units. The depression of the glass tran- sition temperature Tg by dissolved water agrees reasonably well with the prediction by the model of Deubener [J. Deubener, R. Mu¨ ller, H. Behrens, G. Heide, J. Non-Cryst. Solids 330 (2003) 268]. Using water speciation measured by near-infrared spectroscopy we infer that although the effect of OH groups in reducing Tg is larger than that of H2O molecules, the difference in the contribution of both species is smaller than predicted by Deubener et al. (2003). Compared to alkalis and alkaline earth elements the effect of protons on glass fragility is small, mainly because of the relatively low concentration of OH groups (max. 1.5 wt% water dissolved as OH) in the glasses.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: Glass transition ; Pressure effects ; FTIR measurements ; Alkali silicates ; Silicates ; Soda-lime-silica ; Fragility ; Viscosity ; Water in glass ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 69
    facet.materialart.
    Unknown
    Flow and fracturing of viscoelastic media under diffusion-driven bubble growth: An analogue experiment for eruptive volcanic conduits (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: To visualize the behavior of erupting magma in volcanic conduits, we performed shock tube experiments on the ductile–brittle response of a viscoelastic medium to diffusion-driven bubble expansion. A sample of shear-thinning magma analogue is saturated by gas Ar under high pressure. On rapid decompression, Ar supersaturation causes bubbles to nucleate, grow, and coalesce in the sample, forcing it to expand, flow, and fracture. Experimental variables include saturation pressure and duration, and shape and lubrication of the flow path. Bubble growth in the experiments controls both flow and fracturing, and is consistent with physical models of magma vesiculation. Two types of fractures are observed: i) sharp fractures along the uppermost rim of the sample, and ii) fractures pervasively diffused throughout the sample. Rim fractures open when shear stress accumulates and strain rate is highest at the margin of the flow (a process already inferred from observations and models to occur in magma). Pervasive fractures originate when wall-friction retards expansion of the sample, causing pressure to build-up in the bubbles. When bubble pressure overcomes wall-friction and the tensile strength of the porous sample, fractures open with a range of morphologies. Both types of fracture open normally to flow direction, and both may heal as the flow proceeds. These experiments also illustrate how the development of pervasive fractures allows exsolving gas to escape from the sample before the generation of a permeable network via other processes, e.g., bubble coalescence. This is an observation that potentially impact the degassing of magma and the transition between explosive and effusive eruptions.
    Description: Published
    Description: 771-785
    Description: JCR Journal
    Description: reserved
    Keywords: volcanic conduit ; analogue experiment ; vesiculation ; fragmentation ; degassing ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 70
    facet.materialart.
    Unknown
    Geochemical characterization of groundwater and submarine discharge in the south-eastern Sicily (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The main results of a hydrogeochemical survey carried out during 2002–2003 along the coast of the south-eastern Sicily, which aimed at geochemical characterization of both groundwater chemistry and submarine groundwater discharge (SGD) in the area are presented. A general frame of chemical processes affecting the studied groundwater and SGD point out that most samples fall within the calcite-anhydrite-dolomite field (CAD). The chemical composition of the samples within the CAD triangle is essentially controlled by calcite, dolomite and gypsum dissolution, which are the main minerals of the carbonate rocks hosting the aquifers. An additional process evidenced in this study is a mixing with seawater. Nitrate is the most typical ion significantly disturbed in the groundwater chemistry influenced by agricultural activities. The strong correlation with SO4 2 indicates that the use of ammonium sulphate fertilisers is widespread in the study area. The K+ vs. NO3 diagram evidences a correlation occurring at lower and higher concentrations, and implies that there is not a common source of both nitrate and potassium, at least on a regional scale. High-phosphate concentration is found in submarine springs along the coast, specifically in the Donnalucata and Avola areas, while its content in inland wells is generally lower. Phosphate is also associated with high-bicarbonate contents in the Donnalucata area, suggesting its possible origin is phosphate-rich carbonate rocks, which are commonly outcropping in the area.
    Description: Published
    Description: 826-834
    Description: JCR Journal
    Description: reserved
    Keywords: Groundwater ; Seawater ; Submarine groundwater ; discharge ; Hydrogeochemistry ; Water–rock interaction ; 03. Hydrosphere::03.02. Hydrology::03.02.02. Hydrological processes: interaction, transport, dynamics ; 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 71
    facet.materialart.
    Unknown
    Source parameters and scaling relationships in the Friuli-Venezia Giulia (Northeastern Italy) region (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We estimated the source parameters of 53 local earthquakes (2.0 〈ML 〈 5.7) of the Friuli-Venezia Giulia (Northeastern Italy) area, recorded by the short-period local seismic network of the Istituto Nazionale di Oceanografia e Geofisica Sperimentale (OGS), in the period 1995–2003. Data were selected on the basis of high quality locations and focal mechanisms. Standard H/V spectral ratios (HVRS) of the three-component stations of the network were performed in order to assess local amplifications, and only stations showing HVRS not exceeding two were considered for the source parameters estimation. Both velocity and acceleration data were used to compute the SH-wave spectra. Observed spectra were corrected for attenuation effects using an independent regional estimate of the quality factor Q and a station dependent estimate of the spectral decay parameter k. Only earthquakes withML 〉 3.0 recorded with a sampling rate of 125 cps were used to compute k, thus allowing to visualize a linear trend of the high frequency acceleration spectrum up to 40–50 Hz. SH-wave spectra, corrected for attenuation, showed an ω−2 shape allowing a good fit with the Brune model. Seismic moments and Brune radii ranged between 1.5 × 1012 and 1.1 × 1017 Nm and between 0.1 and 2.7 km respectively.We obtainedMo = 1.1 × 1017 Nm for the seismic moment of the Kobarid (SLO) main shock, in good agreement with the Harvard CMT solution (Mo = 3.5 × 1017 Nm). Brune stress drops were confined to the range from 0.07 to 5.31MPa, with an average value of 0.73MPa and seem to be approximately constant over five orders of magnitude of seismic moment. Radiated seismic energy computed from two nearby stations scales with seismic moment according to logEs = 1.30 logMo − 9.06, and apparent stress values are between 0.02 and 4.26MPa. The observed scatter of Brune stress drop data allowed to hypothesize a scaling relation Mo ∝ f −3.43 c between seismic moment and corner frequency in order to accommodate both Brune stress drop and apparent stress scalings. No systematic differences are evidenced between stress parameters of earthquakes with different focal mechanisms. As a consequence, a relation of the seismic stress release with the strength of rocks can be hypothesized. A high correlation (r 〉 0.9) of Brune stress drop is found with both apparent stress and RMS stress drop, according to σB = 2.0 σa and σrms = 2.26 σB respectively.
    Description: Published
    Description: 148-167
    Description: JCR Journal
    Description: reserved
    Keywords: Earthquakes ; Attenuation ; Seismic spectra ; Seismic moment ; Seismic stress ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 72
    facet.materialart.
    Unknown
    Current motion and short term deformation in the Sinai-Suez area from GPS observations (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We analyze observations from eight GPS campaigns carried out between 1997 and 2005 on a network of 13 sites in the Suez–Sinai area, where separation between the African and the Arabian plates takes place. This is the key area to understand if and in which way Sinai behaves like a sub-plate of the African plate and the role played by seismic and geodetic (long-term) deformation release. Our analysis shows that, on average, the Suez–Sinai area motion, in terms of ITRF00 velocities, matches the African plate motion defined by the NNR-NUVEL-1A model. The horizontal principal strain rate axes estimated separately in the Gulf of Suez area and in the northern Sinai vary from compression across the Gulf (−2.2±1.2)×10−8 year−1 to NE extension (1.0±1.5)×10−8 year−1 in the North, showing the presence of two distinct domains, so that in our opinion Sinai cannot be considered simply a unique rigid block. The analysis of GPS baseline length variations shows short-term deformations across the Gulf of Suez, reaching up a maximum value of more than 1 cm in 8 years. Since current geodynamical models do not predict significant tectonic deformation in this area, we work under the hypothesis that a contribute may be expected by post-seismic relaxation effects. Under this hypothesis, we compare the baselines length variations with the post-seismic relaxation field associated with five major local earthquakes occurred in the area, testing two different viscoelastic models. Our results show that the detected short-term deformations are better modeled for viscosity values of 1018 Pa s in the lower crust and 1020 Pa s in the asthenosphere. However, since the modeled post-seismic effect results modest and a certain amount of the detected deformation is not accounted for, we think that an improved modeling should take into account the lateral heterogeneities of crust and upper mantle structures.
    Description: Published
    Description: 485-499
    Description: JCR Journal
    Description: reserved
    Keywords: deformations ; Suez–Sinai ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 73
    facet.materialart.
    Unknown
    NEMO-SN-1 the first "real-time" seafloor observatory of ESONET (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The fruitful collaboration between Italian Research Institutions, particularly Istituto Nazionale di Fisica Nucleare (INFN) and Istituto Nazionale di Geofisica e Vulcanologia (INGV) together with Marine Engineering Companies, led to the development of NEMOSN- 1, the first European cabled seafloor multiparameter observatory. This observatory, deployed at 2060m w.d. about 12 miles off-shore the Eastern coasts of Sicily (Southern Italy), is in real-time acquisition since January 2005 and addressed to different set of measurements: geophysical and oceanographic. In particular the SN-1 seismological data are integrated in the INGV land-based national seismic network, and they arrive in real-time to the Operative Centre in Rome. In the European Commission (EC) European Seafloor Observatory NETwork (ESONET) project, in connection to the Global Monitoring for Environment and Security (GMES) action plan, the NEMO-SN-1 site has been proposed as an European key area, both for its intrinsic importance for geo-hazards and for the availability of infrastructure as a stepwise development in GMES program. Presently, NEMO-SN-1 is the only ESONET site operative. The paper gives a description of SN-1 observatory with examples of data.
    Description: Published
    Description: 462-467
    Description: JCR Journal
    Description: reserved
    Keywords: Seafloor Observatory in real-time communication; ; Geo-hazard mitigation ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 74
    facet.materialart.
    Unknown
    Experimental determination of permeability of Neapolitan Yellow Tuff. (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: This paper presents and discusses the measurement of permeability of Neapolitan Yellow Tuff (NYT) samples obtained in the framework of a study concerning the phenomenon of bradyseism, i.e. the slow vertical movement of soil, in the Campi Flegrei caldera (Campania—Italy). Measurements have been performed under isothermal, non-isothermal and transient non-isothermal conditions using a specifically designed apparatus. Results of measurements of porosity of different samples are also reported. Experimental results in isothermal conditions show that the volume flux through the samples changes linearly with applied pressure. The values of permeability obtained turn out to be independent of the temperature and pressure gradients applied to the samples. This result is consistent with the fact that the permeability is a characteristic of the porous medium, and as such is not affected by temperature and pressure variation, at least in the range examined. The permeability values measured in our laboratories agree quite well with the ones measured in situ by the Agenzia Generale Italiana Petroli (AGIP) during a geothermal exploration of the Campi Flegrei area in 1980. An interesting, still unexplained phenomenon has been detected during transient phases when both pressure and temperature gradients were applied to the samples. The phenomenon consists in an enhancement of volume flux due to heat flux in the transient phase. The extra volume-flux disappears once the steady temperature gradient is reached.
    Description: Published
    Description: 125-136
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: 3.5. Geologia e storia dei sistemi vulcanici
    Description: JCR Journal
    Description: reserved
    Keywords: Campi Flegrei ; hydrothermal systems; ; resurgent calderas ; porous media ; hydraulic permeability ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 75
    facet.materialart.
    Unknown
    Magnetic proxy for the Deep (Pacific) Western Boundary Current variability across the Mid-Pleistocene climate transition (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The Deep Western Boundary Current (DWBC) inflow to the SW Pacific is one of the largest, transporting ~40% of the total input of deep water to the world’s oceans. Here we use a sedimentary record from the giant piston core MD97-2114 collected on the northern flank of the Chatham Rise located at 1935 m water depth, east of New Zealand, to investigate DWBC variability during the Pleistocene epoch when the period of glacial cycles changed progressively from a 41 kyr to 100 kyr rhythm. Magnetic grain-size may be directly related to orbitally forced fluctuations in the strength of the upper circumpolar deep water (UCDW) through its interaction with terrigenous sediments supplied from the south and west. The long-term trends in magnetic properties are characterized by two main perturbations centered at 870 ka (Marine Isotope Stage, MIS 22) 450 ka (MIS 12), which is broadly consistent with the inferred perturbation during the mid-Pleistocene climate transition based on sedimentological paleocurrent reconstruction from Ocean Drilling Program Site 1123 located at 3290 m water depth in the main core of the DWBC flow on the North Chatham Drift. This similarity suggests that both the upper and middle CDW are modulated by similar processes and fluctuations of Antarctic Bottom Water production could be directly responsible for this deep Pacific Ocean inflow variability over the past 1.2 Ma.
    Description: Published
    Description: 107-118
    Description: 2.2. Laboratorio di paleomagnetismo
    Description: JCR Journal
    Description: reserved
    Keywords: DWBC ; Chatham Rise ; New Zealand; ; Pleistocene; ; magnetostratigraphy; ; environmental magnetism ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 76
    facet.materialart.
    Unknown
    Modelling of the April 5, 2003 Stomboli (Italy), paroxysmal eruption from the inversion of broadband seismic data (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: On April 5, 2003, one of the largest eruptions in the last decades was observed at Stromboli volcano, Italy. The eruption occurred in a period of increased volcanic activity, following a first explosion in December 2002, which interrupted the typical moderate “Strombolian” behaviour. We present an exhaustive analysis of the available broadband seismic data and relate them to the observed eruption phases. Prominent features of the seismic signals include an ultra long period signal starting a few tens of seconds prior to the explosive eruption as well as a strong energetic signal a few seconds after the onset of the eruption. Both signals are not exactly synchronized with the other geophysical observations. We present a detailed study of those signals using spectral and particle motion techniques. We estimate eruption parameters and seismic source characteristics by different inversion approaches. Results clearly indicate that the paroxysmal eruption was triggered by a shallow slow thrust-faulting dislocation event with a moment magnitude of Mw=3.0 and possibly associated with a crack that formed previously by dike extrusion. At least one blow-out phase during the paroxysmal explosion could be identified from seismic signals with an equivalent moment magnitude of Mw=3.7 and is represented by a vertical linear vector dipole and two weaker horizontal linear dipoles in opposite direction, plus a vertical force.
    Description: Published
    Description: 164-178
    Description: 3.1. Fisica dei terremoti
    Description: JCR Journal
    Description: reserved
    Keywords: Stromboli ; source inversion ; volcano seismology ; paroxysm ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 77
    facet.materialart.
    Unknown
    Repeating earthquakes from rupture of an asperity under an Antarctic outlet glacier (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The inner regions of the Antarctic continent are generally regarded as nearly aseismic, although microseismicity is known to occur beneath some outlet ice streams, related to the interaction between the fast flowing ice and the bedrock. Here we show the occurrence of unusual earthquakes beneath an Antarctic outlet glacier that share almost the same magnitude, pointing to the repeated rupture of a single asperity. These seismic events produce waveforms with very high similarity and uncommon spectrum and are tightly clustered in space but, unlike other reported instances of repeating earthquakes on a patch of the San Andreas Fault, they occur in frequent irregular swarms. Evidence locates these events at the rock–ice interface under the glacier, and shows the existence of stick–slip motion on a smaller scale than the large slow slip events detected by global seismographs. Seismic behaviour of large glaciers can presumably be connected to surges in ice motion. This study determines a little known environment for fracture dynamics studies, while also contributing to the understanding of the coupling processes between fast flowing glaciers and bedrock that influence ice stream evolution and stability.
    Description: Progetto Nazionale di Ricerca in Antartide (PNRA) Antarctica New Zealand (ANZ)
    Description: Published
    Description: 151–158
    Description: 3.3. Geodinamica e struttura dell'interno della Terra
    Description: JCR Journal
    Description: reserved
    Keywords: Glacial earthquakes ; Glacial dynamics ; Gutenberg-Richter relationship ; Double-difference hypocentre location ; Repeating earthquake ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 78
    facet.materialart.
    Unknown
    The INGV software for the automatic scaling of foF2 and MUF(3000)F2 from ionograms: A performance comparison with ARTIST 4.01 from Rome data (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The performance of a computer program, called Autoscala, for the automatic scaling of foF2 and MUF(3000)F2 from ionograms has been extensively tested. Results of comparisons between automatically and manually scaled data are shown both for Autoscala and for ARTIST (release 4.01). Particular attention has been paid to the cases in which the ionograms have a truncated trace. The problem of the rejection of bad quality ionograms has been also considered. The analysis of data shows that the reliability of values automatically given as output by Autoscala is good. For the data set considered Autoscala seems to operate better than ARTIST.
    Description: Published
    Description: 1063-1073
    Description: 1.7. Osservazioni di aeronomia
    Description: 3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale
    Description: JCR Journal
    Description: reserved
    Keywords: Ionosonde ; Ionogram scaling ; Automatic scaling ; Ionosphere monitoring ; 01. Atmosphere::01.02. Ionosphere::01.02.99. General or miscellaneous ; 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation ; 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 79
    facet.materialart.
    Unknown
    Seismic hazard assessment at Mt. Vesuvius: Maximum expected magnitude (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: This paper deals with the problem of seismicity at Mt. Vesuvius with a view to providing an estimation of the maximum expected earthquake. Integrated analysis of both historical and current seismicity as well as the geological conditions of Vesuvius and the surrounding areas show that seismogenetic structures may fall within the crater axis and at the boundaries of the volcanic complex. While activation of the whole seismogenetic volume detected by seismicity in the past 30 years would indicate a total seismic moment of Mo = 7.1E+ 15 Nm for a magnitude M = 4.5, knowledge of the area's geological structure suggests faulting surfaces of about 32 km2 with an associated magnitude of M = 5.4. The areas of maximum expected damage differ according to the orientation of the hypothesized structure. Analysis of geological and geophysical data and the damage associated to the AD 62 earthquake shows that the prevailing directions in the faulting planes are NE–SW in the eastern sector of the volcanic complex, and roughly WNW–ESE in the southern part of the volcano along the coast. Comparison of instrumental seismicity and historical data reveals two significantly different energy levels: a lower earthquake level with Mmax = 4.5, corresponding to current seismicity and that which accompanied volcanic activity in the eruptive period from 1631–1944; an upper level with Mmax = 5.4, represented by the AD 62 earthquake. The two levels correspond to two stress states and different seismogenetic structures.
    Description: Published
    Description: 139-149
    Description: 3.6. Fisica del vulcanismo
    Description: 3.10. Sismologia storica e archeosismologia
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: 5.1. TTC - Banche dati e metodi macrosismici
    Description: JCR Journal
    Description: reserved
    Keywords: Mt. Vesuvius ; seismic hazard ; historical seismicity ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 80
    facet.materialart.
    Unknown
    Hydrothermal fluid circulation and its effect on caldera unrest (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: This paper focuses on the role that hydrothermal systems may play in caldera unrest. Changes in the fluid chemistry, temperature, and discharge rate of hydrothermal systems are commonly detected at the surface during volcanic unrest, as hydrothermal fluids adjust to changing subsurface conditions. Geochemical monitoring is carried out to observe the evolving system conditions. Circulating fluids can also generate signals that affect geophysical parameters monitored at the surface. Effective hazard evaluation requires a proper understanding of unrest phenomena and correct interpretation of their causes. Physical modeling of fluid circulation allows quantification of the evolution of a hydrothermal system, and hence evaluation of the potential role of hydrothermal fluids during caldera unrest. Modeling results can be compared with monitoring data, and then contribute to the interpretation of the recent caldera evolution. This paper: 1) describes the main features of hydrothermal systems; 2) briefly reviews numerical modeling of heat and fluid flow through porous media; 3) highlight the effects of hydrothermal fluids on unrest processes; and 4) describes some model applications to the Phlegrean Fields caldera. Simultaneous modeling of different independent parameters has proved to be a powerful tool for understanding caldera unrest. The results highlight the importance of comprehensive conceptual models that incorporate all the available geochemical and geophysical information, and they also stress the need for high-quality, multi-parameter monitoring and modeling of volcanic activity.
    Description: Accepted
    Description: 3.6. Fisica del vulcanismo
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: open
    Keywords: hydrothermal activity ; caldera unrest ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 81
    facet.materialart.
    Unknown
    A data sequence acquired at Mt. Etna during the 2002–2003 eruption highlights the potential of continuous gravity observations as a tool to monitor and study active volcanoes (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: A 2.5-month long gravity sequence, encompassing the starting period of the 2002–2003 Etna eruption and coming from a summit station only 1 km away from the new fractures, is presented and discussed. The sequence comprises four hours-long anomalies that have a great chance to reflect mass redistributions linked to the ensuing activity. In particular, the start of the eruptive activity on the northeastern flank was marked by a gravity decrease as strong as about 400 microGal, which reverted soon afterwards. This strong decrease/increase anomaly is interpreted as the opening, by tectonic forces, of a fracture system along the Northeastern Rift of Mt. Etna, followed by an intrusion of magma from the central conduit to the new fractures. They were used by the intruding magma as a path to the eruptive vents at lower elevations. Afterwards, on three occasions, in November and December 2002, 6–12 h-lasting gravity decreases, with amplitude ranging between 10 and 30 microGal, were observed simultaneously with increases in the amplitude of the volcanic tremor from four seismic stations. A correlation analysis, between the gravity signal and the overall spectral amplitude of each tremor sequence is performed over the 7 November–9 December period. A marked anti-correlation is found over each contemporaneous gravity decrease/tremor increase, while, over the rest of the investigated period, the correlation is negligible. Accordingly, a joint source is inferred to have acted during the occurrence of the three common anomalies. On the grounds of some volcanological observations spanning the period covered by our analysis, we propose the temporary accumulation of a gas cloud at some level within the plumbing system of the volcano to have acted as a joint source. The present work is a further evidence of the potential of continuous gravity observations as a tool to monitor and study active volcanoes and encourages their employment in spite of the difficulty of running spring gravimeters in a continuous fashion under the adverse conditions normally encountered on the summit zone of an active volcano.
    Description: Published
    Description: 320–329
    Description: 2.6. TTC - Laboratorio di gravimetria, magnetismo ed elettromagnetismo in aree attive
    Description: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Gravity anomalies ; Magma intrusion ; 04. Solid Earth::04.03. Geodesy::04.03.05. Gravity variations
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 82
    facet.materialart.
    Unknown
    Evidence of active crustal deformation of the Colli Albani volcanic area (central Italy) by GPS (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Colli Albani is a volcanic complex close to the city of Rome. Here we show results from GPS campaigns performed in the time span 1995-1996.
    Description: Published
    Description: 55-65
    Description: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: crustal deformation, GPS, Colli Albani ; 04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 83
    facet.materialart.
    Unknown
    From COST 271 to 296 EU actions on ionospheric monitoring and modelling for terrestrial and Earth-space radio systems (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The ionospheric community has long been aware that co-operative research on an international basis is essential to deal with temporal and spatial changes in the ionosphere that influence the performance of terrestrial and Earth-space radio systems. The EU COST (Cooperation in the field of Scientific and Technical Research) 271 Action on "Effects of the Upper Atmosphere on Terrestrial and Earthspace Communications" has had during the period of October 2000-August 2004 the following main objectives: (1) to evaluate the influence of upper atmospheric conditions on terrestrial and Earth-space communications, (2) to develop methods and techniques to improve ionospheric models over Europe for telecommunication and navigation applications and (3) to transfer the results to the appropriate radiocommunication study groups of the International Telecommunication Union (ITU-R) and other national and international organizations dealing with the modern communication systems. At the beginning of 2005 the new 296 Action in the COST Telecommunications, Information Science and Technology domain on "Mitigation of lonospheric Effects on Radio Systems (MIERS)" was approved for the period 2005-2009. The main objectives of the MIERS are: (a) to support and enhance the existing European facilities for historical and real-time digital ionospheric data collection and exchange; (b) to develop an integrated approach to ionospheric modelling, create the mechanism needed to ingest processed data into models, extend and develop suitable mitigation models and define the protocols needed to link models together; and (c) to strengthen the areas of expertise that already exist by stimulating closer cooperation between scientists and users, focusing the scope of all the previous COST ionospheric related studies to the mitigation of ionospheric effects on radio systems. This paper summarises briefly how the major objectives of the COST27l Action have been achieved and what are the most important activities to be undertaken in the follow-on COST296 Action.
    Description: Published
    Description: 899-903
    Description: 3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale
    Description: N/A or not JCR
    Description: reserved
    Keywords: Ionosphere ; Monitoring and modeling ; Radiocommunication ; 01. Atmosphere::01.02. Ionosphere::01.02.99. General or miscellaneous ; 05. General::05.07. Space and Planetary sciences::05.07.02. Space weather
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 84
    facet.materialart.
    Unknown
    Background seismicity in the Central Apennines of Italy: The Abruzzo region case study (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We investigate background seismic activity of the Abruzzo region, a 5000 km2 area located within the Central Apennines of Italy, where in the past 600 years at least 5 large earthquakes (I=XI – X) have occurred. Between April 2003 and September 2004, a dense temporary seismic network composed of 30 digital three-component seismic stations recorded 850 earthquakes with 0.9〈ML〈3.7. We present earthquake locations and focal mechanisms obtained by standard procedures and an optimized velocity model computed with a search technique based on genetic algorithms. The seismicity occurs at a low and constant rate of ~2.6 e-04 events/day*km2 and is sparsely distributed within the first 15 km of the crust. Minor increases in the seismicity rate are related to the occurrence of small and localised seismic sequences that occur at the tip of major active normal faults along secondary structures. We observe that during the 16 months of study period, the Fucino fault system responsible for the 1915 Fucino earthquake (MS=7.0), and the major normal faults of the area, did not produce significant seismic activity. Fault plane solutions evaluated using P-wave polarity data show the predominance of normal faulting mechanisms (~55%) with NE-trending direction of extension coherent with the regional stress field active in this sector of the Apennines. Around 27% of the focal solutions have pure strike-slip mechanisms and the rest shows transtensional faulting mechanisms that mainly characterise the kinematics of the secondary structures activated by the small sequences. We hypothesize that the largest known NW-trending normal faults are presently locked and we propose that in the case of activation, the secondary structures located at their tips may act as transfer faults accommodating a minor part of the extensional deformation with strike-slip motion.
    Description: Published
    Description: 80-92
    Description: 3.1. Fisica dei terremoti
    Description: JCR Journal
    Description: reserved
    Keywords: background seismicity ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 85
    facet.materialart.
    Unknown
    Changing conditions of magma ascent and fragmentation during the Etna 122 BC basaltic Plinian eruption: Evidence from clast microtextures (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The Etna 122 BC basaltic eruption had two Plinian phases, each preceded and followed by weak phreatic and phreatomagmatic activity. This study infers changing eruption dynamics from density, grain size, and microtextural data from the erupted pyroclasts. The Plinian clasts show no evidence for quenching by external water; instead, all clasts are microvesicular and have high bubble number densities relative to the products of weaker basaltic explosive eruptions, suggesting that the 122 BC magma underwent coupled degassing linked to rapid ascent and decompression. This coupled degassing was probably enhanced by crystallization of abundant microlites, which increased the magma's effective viscosity during conduit ascent. Detailed measurements of vesicles and microlites show wide variations in number densities, size distributions, and shapes among clasts collected over narrow stratigraphic intervals. For such a diversity of clasts to be expelled together, portions of melt with contrasting ascent and degassing histories must have arrived at the fragmentation surface at essentially the same time. We suggest that a parabolic velocity profile across the conduit ensured that magma near the conduit walls ascended more slowly than magma along the axis, leading to a longer residence time and more advanced degrees of outgassing and crystallization in the marginal magma. In our model, accumulation of this outgassed, viscous magma along conduit walls reduced the effective radius of the shallow conduit and led to blockages that ended the Plinian phases.
    Description: Published
    Description: 333-354
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: basaltic Plinian ; Etna ; vesicles ; microlites ; conduit dynamics ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 86
    facet.materialart.
    Unknown
    A composite record of Late Pleistocene relative geomagnetic paleointensity from Wilkes Land Basin (Antarctica) (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We report high-resolution paleomagnetic records obtained from six piston cores recovered on the continental rise of theWilkes Land Basin (WLB), East Antarctica, in the frame of the Italian/Australian Wilkes Land Glacial History (WEGA) project. The studied cores, with a length of ca. 4m each, were collected from the gentle and steep sides of sedimentary ridges present in the lower part of the continental rise, and consist of very fine-grained sediments. Paleomagnetic measurements were carried out on u-channel samples. Apart from a low-coercivity magnetic overprint, removed after the first steps of alternating field demagnetization, each core is characterized by a well defined characteristic remanent magnetization. Paleomagnetic inclinations fluctuate around the expected value (of ca. −77◦) for such high latitude sites and always indicate normal magnetic polarity. Short period oscillations to anomalously shallow paleomagnetic inclinations (up to −20◦) were identified at different levels of the sampled sequences; positive (reverse) inclination values were however not observed. Specific rock magnetic measurements indicate a substantial homogeneity of the magnetic mineralogy in the sampled sequences. For each core we reconstructed curves of relative paleointensity (RPI, as computed by NRM20mT/κ and NRM20mT/ARM20mT) variation of the geomagnetic field. An original age modelwas established by tuning the individual RPI curves with the available global and regional reference RPI stacks. Paleomagnetic results, supported by other limited bio- and chronostratigraphic constraints, establish that all the cores are Late Pleistocene in age: two provide an expanded record of the last ca. 30 ka (PC18 and PC19), three span the last ca. 100, 200 and 300 ka (respectively, PC25, PC27 and PC26), and one reaches back to ca. 780 ka (PC20), approaching the Brunhes–Matuyama transition. Thus, the WEGA paleomagnetic record provides the first experimental data documenting the dynamics and amplitude of the geomagnetic field variations at high southern latitudes during the Brunhes Chron. The individual normalized RPI records were merged in aWEGARPI stacking curve spanning the last 300 kyr. The comparison of theWEGARPI individual and stacked curves with the global references RPI stacks shows that geomagnetic paleointensity variations, with periods longer than a few to tens kyr depending on the sedimentation rate, can be safely recognized in this sector of the peri-Antarctic margins. Furthermore, the stacking of the individual ChRM inclination records indicates that the recurrent swings to shallow paleomagnetic inclinations may be correlated to the main known geomagnetic excursions of the Brunhes Chron, supporting the validity of the age models. The reconstructed average sediment accumulation rates for the individual cores range from 0.6 to 19 cm/ka and are compatible with their position within the WLB, with the lowest rates found close to the ridge of the sedimentary drifts. Moreover, the high-resolution age models obtained in this study provide original constraints to assess chronology, rates and amplitudes of the climatic and environmental processes affecting this key area of the peri-Antarctic margins during the Late Pleistocene.
    Description: Published
    Description: 223-242
    Description: 2.2. Laboratorio di paleomagnetismo
    Description: JCR Journal
    Description: reserved
    Keywords: Paleomagnetism; Relative paleointensity; Geomagnetic excursions; Antarctica; Brunhes Chron ; 04. Solid Earth::04.05. Geomagnetism::04.05.02. Geomagnetic field variations and reversals ; 04. Solid Earth::04.05. Geomagnetism::04.05.05. Main geomagnetic field
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 87
    facet.materialart.
    Unknown
    Long Term Trends of the critical frequency of the F2 layer at Northern and Southern high latitude regions (2007)
    Elsevier
    Details
    Publication Date: 2017-04-03
    Description: Abstract The long-term behaviour of the plasma frequency of the F2 layer, foF2, is investigated to contribute to the discussion about the natural or anthropogenic origin of the ionospheric long-term changes. In this paper, long time series of hourly foF2 data from two high latitude ionospheric observatories of both the hemispheres are analysed. A decreasing trend of foF2 is found confirming a previous result obtained by using the foF2 monthly medians from Antarctic stations. This negative trend does not show a clear dependence on the long-term behaviour of the geomagnetic activity impact on the ionosphere.
    Description: Published
    Description: 607-612
    Description: 3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale
    Description: JCR Journal
    Description: reserved
    Keywords: long term trends ; 01. Atmosphere::01.02. Ionosphere::01.02.04. Plasma Physics ; 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 88
    facet.materialart.
    Unknown
    Geodynamic implications of deep mantle upwelling in the source of Tertiary volcanics from the Veneto region (South-Eastern Alps) (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Major and trace element and Sr–Nd–Hf–Pb isotopic data for the most primitive Tertiary lavas from the Veneto region (South-Eastern Alps, Italy) show the typical features of HIMU hotspot volcanism, variably diluted by a depleted asthenospheric mantle component (87Sr/86Sri=0.70306–0.70378; "Ndi=+3.9 to +6.8; "Hfi=+6.4 to +8.1, 206Pb/204Pbi=18.786–19.574). P-wave seismic tomography of the mantle below the Veneto region shows the presence of low-velocity anomalies at depth, which is consistent with possible upwellings of plume material. Between the depths of 100–250 km the velocity anomalies are approximately 2–2.5% slower than average, implying a temperature excess of about 220–280 K, in agreement with estimates for other mantle plumes in the world. In this context, the Veneto volcanics may represent the shallow expression of a mantle upflow. The presence of a HIMU-DM component in a collision environment has significant geodynamic implications. Slab detachment and ensuing rise of deep mantle material into the lithospheric gap is proposed to be a viable mechanism of hotspot magmatism in a subduction zone setting.
    Description: Published
    Description: 563–590
    Description: 3.3. Geodinamica e struttura dell'interno della Terra
    Description: JCR Journal
    Description: reserved
    Keywords: trace-element ; isotopic composition ; alkali basalts ; central-Europe ; slab break-off ; plume ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 89
    facet.materialart.
    Unknown
    A late Cretaceous contamination episode of the European–Mediterranean mantle (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: One of the most challenging issues about the Tertiary–Quaternary alkaline magmatism spreading across the Euro-Mediterranean region is the assessment of both the nature of its mantle source and the mechanism responsible for the common HIMU-like (High μ=high 238U/204Pb) character of erupted lavas, enduring over about 100 million years in diverse tectonic environments. In this paper we try to reconcile geochemical and geophysical data through a multidisciplinary investigation on geochemistry, timing and locations of the main Na-rich alkaline volcanic centers, seismic tomographic images and plate kinematics. We propose that the common component of the Euro-Mediterranean mantle derives from a contamination episode triggered by the rise of the Central Atlantic Plume (CAP) head. Plate reconstruction shows that at late Cretaceous- Paleocene time the oldest magmatic centers of the Euro-Mediterranean region were located more than 2000 km SW of their present day position, in proximity of the CAP hot spot location, where seismic tomography detects a broad low seismic velocity region in the lower mantle. The northeastward migration of the Eurasian and African plates could have involved also part of the CAP contaminated mantle, which moved in the same direction being coupled to the lithospheric plates, thus explaining the presence of geochemically-uniform material spread in the sub-lithospheric Euro-Mediterranean mantle. During the Tertiary, regional-scale convection and related processes such as rifting, back-arc spreading, slab detachment/windows, may have favored upwelling and partial melting of the frayed plume head material via adiabatic decompression, shaping the spatial and temporal distribution of HIMU-like volcanics. The growing supply of subducted lithosphere may explain as well the increase of crustal isotopic signatures of alkaline magmas with time. In our opinion, the Euro-Mediterranean upper mantle contamination can be eventually related to a global event occurred during the Cretaceous as a consequence of a mantle avalanche caused by the Tethys closure.
    Description: MIUR 2005-2007, prot. n. 2005055415_002, Poli G.
    Description: Published
    Description: 15–27
    Description: 3.3. Geodinamica e struttura dell'interno della Terra
    Description: JCR Journal
    Description: partially_open
    Keywords: Cenozoic HIMU–OIB volcanism ; Euro-Mediterranean mantle ; geochemistry ; mantle tomography ; plate kinematics ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 90
    facet.materialart.
    Unknown
    Subduction polarity reversal at the junction between the Western Alps and the Northern Apennines, Italy (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The controversial relationship between the orogenic segments of the Western Alps and the Northern Apennines is here explored integrating recently published 3D tomographic models of subduction with new and re-interpreted geological observations from the eclogitic domain of the Voltri Massif (Ligurian Alps, Italy), where the two belts joint each other. The Voltri Massif is here described as an extensional domain accommodating the opposing outward migration of the Alpine and Apennine thrust fronts, since about 30–35 Ma. Using tomographic images of the upper mantle and paleotectonic reconstructions, we propose that this extensional setting represents the surface manifestation of an along strike change in polarity of the subducted oceanic slab whose polarity changed laterally in space and in time. Our tectonic model suggests that the westward shift of the Alpine thrust front from the Oligocene onward was the consequence of the toroidal asthenospheric flow induced by the retreat of the Apenninic slab.
    Description: Published
    Description: 34–50
    Description: 3.3. Geodinamica e struttura dell'interno della Terra
    Description: JCR Journal
    Description: reserved
    Keywords: Western Alps ; Northern Apennines ; Voltri Massif ; Tomography ; Kinematic reconstruction ; Extensional detachment ; Toroidal flow ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 91
    facet.materialart.
    Unknown
    A Local Intermittency Measure (LIM) approach to the detection of geomagnetic jerks (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: In the present work we investigate the temporal distributions of the geomagnetic jerks occurring in the last three decades of the 20th century using a new method of analysis based on the wavelet transform: the Local Intermittency Measure (LIM). This method, which allows us to single out intermittent structures within a given time series, was applied to geomagnetic monthly means time series of the eastward magnetic field component (Y) of 44 worldwide observatories. We study the bimodal distribution of the jerk occurrence in time for the 1978 and 1991 events and point out a local/regional jerk in South Africa and in the Pacific Ocean which happened around 1986. The worldwide character of the 1999 geomagnetic jerk is also investigated integrating the LIM analysis with the traditional straight-line fit.
    Description: Published
    Description: 261-272
    Description: 3.4. Geomagnetismo
    Description: JCR Journal
    Description: reserved
    Keywords: geomagnetic jerk ; Local Intermittency Measure ; geomagnetic secular variation ; wavelet analysis ; 04. Solid Earth::04.05. Geomagnetism::04.05.02. Geomagnetic field variations and reversals
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 92
    facet.materialart.
    Unknown
    Inverse and forward modelling of groundwater circulation in a seismically active area (Monferrato, Piedmont, NW Italy): Insights into stress-induced variations in water chemistry (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Reaction path modelling, coupled with preparatory inverse modelling, was applied to test this model's ability to reproduce the wide compositional range of ground waters circulating in a restricted area in Piedmont, Italy. This approach is based on the assumption that the chemistry of groundwater evolves through a series of partial equilibria with secondary minerals until it reaches its final composition. PHREEQC [Parkhurst, D.L., Appelo, C.A.J., 1999. User's guide to PHREEQC-A computer program for speciation, reaction-path, 1D-transport, and inverse geochemical calculations. U.S. Geological Survey Water-Resources Investigations Report, pp. 99-4259] and EQ3/6 [Wolery, T.J., Daveler, S.A., 1992. EQ6, A Computer Program for Reaction Path Modeling of Aqueous Geochemical Systems: Theoretical Manual, User's Guide and Related Documentation (version 7.0). Report UCRl-MA-110662 PT IV. Lawrence Livermore National Laboratory, Livermore, California] software packages were used to effect simulations. Reaction-path modelling was performed in time mode, taking into account the different rates of dissolution of each dissolving mineral. Data from literature regarding the kinetic parameters of dissolving minerals and the mineralogical composition of the host-rock were used. The results of the reaction-path modelling show that the composition of the analysed water samples was adequately reproduced, notwithstanding the hydrogeological complexity of the studied area. Modelling results provided very different water compositions as an effect of the chemical maturity, the physico-chemical parameters ( fCO2, fO2, and temperature) and the variable amounts of gypsum among dissolving rock-forming minerals, which occur in Miocene levels of the sedimentary sequence. Further variability is related to the occasional contribution of brackish waters trapped in euxinic marly sediments, locally sealed by overlying clays, that have assumed an artesian character. The composition of some of the water samples can only be predicted by simulation runs performed at a temperature higher than that of the outlet (40 °C). These warm waters probably circulate in a restricted area near the town of Nizza Monferrato. The same area has recently been affected by moderate seismicity, which has been accompanied by changes in either the temperature or chemistry, or both, of the ground waters. The changes recorded, interpreted as having been triggered by variations in the local/regional stress load and/or seismic activity, have to be ascribed to the vertical heterogeneity of the aquifers, where waters of different temperature, salinity and chemical composition circulate and occasionally mix.
    Description: Municipality of Nizza Monferrato (Asti, Italy) and the Regional Administration of Regione Piemonte (Italy)
    Description: Published
    Description: 14-39
    Description: 1.1. TTC - Monitoraggio sismico del territorio nazionale
    Description: JCR Journal
    Description: reserved
    Keywords: Reaction-path modelling ; EQ3/6 ; Inverse modelling ; Tertiary Piedmont Basin ; Monferrato ; Seismicity ; 03. Hydrosphere::03.04. Chemical and biological::03.04.03. Chemistry of waters
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 93
    facet.materialart.
    Unknown
    A new campaign for oblique-incidence ionospheric sounding over Europe and its data application (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: New systematic oblique ionospheric radio sounding measurements over Central Europe, concerning the radio links between Inskip (UK, 53.51N, 2.51W) and Rome (Italy, 41.81N, 12.51E) and between Inskip and Chania (Greece, 35.71N, 24.01E), have been performed since November 2003. Different long-term (i.e. monthly median) ionospheric predictions and nowcasting techniques have been applied and compared with the oblique-incidence radio sounding measurements. The MUF (basic maximum usable frequency) measurements observed during the early part of the experiment have been used to compare the performances of different methods. The preliminary analysis has shown good performances for the long-term prediction models, in particular in winter months for ICEPAC (ionospheric communications enhanced profile analysis and circuit) and in equinox/summer months for ASAPS (advanced stand-alone prediction system) and SIRM&LKW (simplified ionospheric regional model & lockwood). The nowcasting methods SIRMUP&LKW (SIRM updating method & lockwood) and ISWIRM (instantaneous space weighted ionospheric regional model) reveal good results for moderate and disturbed geomagnetic conditions when compared with the long-term prediction methods.
    Description: Published
    Description: 854-865
    Description: 3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale
    Description: JCR Journal
    Description: reserved
    Keywords: Ionosphere ; Monthly median models ; Nowcasting models ; Oblique radio sounding ; 01. Atmosphere::01.02. Ionosphere::01.02.03. Forecasts ; 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 94
    facet.materialart.
    Unknown
    Reply to Comment on “Historical measurements of the Earth’s magnetic field compared with remanence directions from lava flows in Italy over the last four centuries”, by Tanguy J.C., Principe C., Arrighi S. (2008)
    Elsevier
    In:  Tanguy, J.C., Principe, C., Arrighi, S., 2005. Comment on “Historical measurements of the Earth’s magnetic field compared with remanence directions from lava flows in Italy over the last four centuries”. In: Lanza, R., Meloni, A., Tema, E. (Eds.), Phys Earth Planet. Inter. 152, 116–120.
    Details
    Publication Date: 2017-04-04
    Description: A comparison of the geomagnetic directions derived from lava flows of Italian volcanoes with those derived from direct historical measurements of the Earth’s magnetic field (Lanza et al., 2005) yielded two main results: (1) The general agreement between the two data sets already noted by previous authors (Rolph et al., 1987; Incoronato et al., 2002; Tanguy et al., 2003) was better substantiated. (2) The thermal remanent magnetization (TRM) direction of most flows was shown to deviate from the corresponding historical direction by a small angle θ. In most cases, this angle was larger than the experimental error on the TRM direction as given by the α95 semi-angle of confidence of Fisher’s statistics, i.e. θ 〉 α95. The conclusion drawn from these results was straightforward: a better understanding of the causes of the TRM deviation is required if we are to fully exploit the precision of TRM data from Italian volcanoes when their α95 value is less than 2.5–3.0◦.
    Description: Published
    Description: 121-124
    Description: 1.6. Osservazioni di geomagnetismo
    Description: 2.6. TTC - Laboratorio di gravimetria, magnetismo ed elettromagnetismo in aree attive
    Description: 3.4. Geomagnetismo
    Description: JCR Journal
    Description: reserved
    Keywords: Secular variation ; Historical magnetic measurements ; Thermal remanent magnetization ; Volcanic rocks ; 04. Solid Earth::04.05. Geomagnetism::04.05.02. Geomagnetic field variations and reversals ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 95
    facet.materialart.
    Unknown
    Age of the Corsica–Sardinia rotation and Liguro–Provençal Basin spreading: new paleomagnetic and Ar/Ar evidence (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The age of spreading of the Liguro–Provençal Basin is still poorly constrained due to the lack of boreholes penetrating the whole sedimentary sequence above the oceanic crust and the lack of a clear magnetic anomaly pattern. In the past, a consensus developed over a fast (20.5–19 Ma) spreading event, relying on old paleomagnetic data from Oligo–Miocene Sardinian volcanics showing a drift-related 30° counterclockwise (CCW) rotation. Here we report new paleomagnetic data from a 10-mthick lower–middle Miocene marine sedimentary sequence from southwestern Sardinia. Ar/Ar dating of two volcanoclastic levels in the lower part of the sequence yields ages of 18.94±0.13 and 19.20±0.12 Ma (lower–mid Burdigalian). Sedimentary strata below the upper volcanic level document a 23.3±4.6° CCW rotation with respect to Europe, while younger strata rapidly evolve to null rotation values. A recent magnetic overprint can be excluded by several lines of evidence, particularly by the significant difference between the in situ paleomagnetic and geocentric axial dipole (GAD) field directions. In both the rotated and unrotated part of the section, only normal polarity directions were obtained. As the global magnetic polarity time scale (MPTS) documents several geomagnetic reversals in the Burdigalian, a continuous sedimentary record would imply that (unrealistically) the whole documented rotation occurred in few thousands years only. We conclude that the section contains one (or more) hiatus(es), and that the minimum age of the unrotated sediments above the volcanic levels is unconstrained. Typical back-arc basin spreading rates translate to a duration ≥3 Ma for the opening of the Liguro–Provençal Basin. Thus, spreading and rotation of Corsica–Sardinia ended no earlier than 16 Ma (early Langhian). A 16–19 Ma, spreading is corroborated by other evidences, such as the age of the breakup unconformity in Sardinia, the age of igneous rocks dredged west of Corsica, the heat flow in the Liguro–Provençal Basin, and recent paleomagnetic data from Sardinian sediments and volcanics. Since Corsica was still rotating/drifting eastward at 16 Ma, it presumably induced significant shortening to the east, in the Apennine belt. Therefore, the lower Miocene extensional basins in the northern Tyrrhenian Sea and margins can be interpreted as synorogenic "intra-wedge" basins due to the thickening and collapse of the northern Apennine wedge.
    Description: Published
    Description: 231-251
    Description: 2.2. Laboratorio di paleomagnetismo
    Description: JCR Journal
    Description: reserved
    Keywords: Paleomagnetism ; Corsica-Sardinia ; Liguro-Provençal Basin ; Back-arc spreading ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 96
    facet.materialart.
    Unknown
    GEOSTAR: a GEophysical and Oceanographic STation for Abyssal Research (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The GEOSTAR is a technological and scientific project aimed at the realisation of an autonomous benthic observatory able to perform long-term, continuous and integrated geophysical and environmental measurements in deep seafloors. The observatory is conceived to be a node of existing and future geophysical monitoring networks, making possible their extension offshore. The GEOSTAR observatory prototype hosts sensors for seismic, geomagnetic, gravimetric, geochemical and oceanographic researches up to abyssal depths (4000 m). The first 1-year scientific mission is foreseen within the end of the millennium in the abyssal plain (3400 m) of the Southern Tyrrhenian Sea, where key information about the geodynamics and oceanography of the whole Mediterranean basin can be acquired.
    Description: Published
    Description: 175-183
    Description: JCR Journal
    Description: reserved
    Keywords: Seafloor observatories ; Geophysics ; Water geochemistry ; Physical oceanography ; 03. Hydrosphere::03.01. General::03.01.08. Instruments and techniques ; 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring ; 03. Hydrosphere::03.02. Hydrology::03.02.07. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 97
    facet.materialart.
    Unknown
    Simple additional constraints on regional models of the geomagnetic secular variation field (2008)
    Elsevier
    Details
    Publication Date: 2017-04-03
    Description: Lecter section of Physics of the Earth and Planetary Interiors 97 (1996)
    Description: Standard ways of building regional models of the geomagnetic field fail when one wishes to model secular variation (SV). The reason for this is that the SV is mainly a large-scale feature, while regional modelling is most appropriate for characterizing small-scale features. The new idea presented in this note consists in reducing this effect by requiring that the spatial derivatives of the SV produced by the regional model fit the values given by global (and smoother) models such as the international geomagnetic reference field.
    Description: Published
    Description: 15-21
    Description: N/A or not JCR
    Description: reserved
    Keywords: geomagnetic regional models ; secular variation ; 04. Solid Earth::04.05. Geomagnetism::04.05.03. Global and regional models ; 05. General::05.01. Computational geophysics::05.01.03. Inverse methods
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 98
    facet.materialart.
    Unknown
    Space weather and RF communications: Monitoring and modelling (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Preface to Journal of Atmospheric and Solar-Terrestrial Physics 67 (2005)
    Description: At the beginning of the new millennium, ionospheric physics and its application in new technologies are at a point of significant change and new development. Ionospheric studies in the past found application in the traditional areas of broadcast and terrestrial radio communications. It has become clear, in recent years, that an understanding of the ionosphere, as a part of the upper atmosphere, is central to the design of many modern communication, navigation and positioning systems. An important additional role has also been recognized in the areas of space weather science and services. This issue of the Journal of Atmospheric and Solar-Terrestrial Physics collects selected contributions presented at the Solar-Terrestrial Sciences session ST14 on "Space weather and RF communications: monitoring and modelling" held during the first General Assembly of the European Geosciences Union (Nice, France, 25–30 April 2004).
    Description: Published
    Description: 1053
    Description: 3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale
    Description: JCR Journal
    Description: reserved
    Keywords: Space weather ; RF communications ; Ionospheric physics ; 01. Atmosphere::01.01. Atmosphere::01.01.04. Processes and Dynamics ; 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation ; 05. General::05.07. Space and Planetary sciences::05.07.02. Space weather
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 99
    facet.materialart.
    Unknown
    Inter-laboratory calibration of low-field magnetic and anhysteretic susceptibility measurements (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Inter-laboratory and absolute calibrations of rock magnetic parameters are fundamental for grounding a rock magnetic database and for semi-quantitative estimates about the magnetic mineral assemblage of a natural sample. Even a dimensionless ratio, such as anhysteretic susceptibility normalized by magnetic susceptibility (Ka/K) may be biased by improper calibration of one or both of the two instruments used to measure Ka and K. In addition, the intensity of the anhysteretic remanent magnetization (ARM) of a given sample depends on the experimental process by which the remanence is imparted. We report an inter-laboratory calibration of these two key parameters, using two sets of artificial reference samples: a paramagnetic rare earth salt, Gd2O3 and a commercial "pozzolanico" cement containing oxidized magnetite with grain size of less than 0.1 m according to hysteresis properties. Using Gd2O3 the 10 Kappabridges magnetic susceptibility meters (AGICO KLY-2 or KLY-3 models) tested prove to be cross-calibrated to within 1%. On the other hand, Kappabridges provide a low-field susceptibility value that is ca. 6% lower than the tabulated value for Gd2O3, while average high-field susceptibility values measured on a range of instruments are indistinguishable from the tabulated value. Therefore, we suggest that Kappabridge values should be multiplied by 1.06 to achieve absolute calibration. Bartington Instruments magnetic susceptibility meters with MS2B sensors produce values that are 2–13% lower than Kappabridge values, with a strong dependence on sample centering within the sensor. The Ka/K ratio of ca. 11, originally obtained on discrete cement samples with a 2G Enterprises superconducting rock magnetometer and a KLY-2, is consistent with reference parameters for magnetites of grain size 〈0.1 m. On the other hand, Ka values from a 2G Enterprises magnetometer and K values from a Bartington Instruments MS2C loop sensor for u-channel and discrete cement samples, will produce average Ka/K values that are unrealistically high if not properly corrected for the nominal volume detected by the sensors for these instruments. Inter-laboratory measurements of K and Ka for standard paleomagnetic plastic cubes filled with cement indicate remarkable differences in the intensity of the newly produced ARMs (with a standard deviation of ca. 21%), that are significantly larger than the differences observed from the calibration of the different magnetometers employed in each laboratory. Differences in the alternating field decay rate are likely the major source of these variations, but cannot account for all the observed variability. With such large variations in experimental conditions, classical interpretation of a "King plot" of Ka versus K would imply significant differences in the determination of grain size of magnetite particles on the same material.
    Description: Published
    Description: 25-38
    Description: 2.2. Laboratorio di paleomagnetismo
    Description: JCR Journal
    Description: reserved
    Keywords: Rock magnetism ; Magnetic susceptibility ; Anhysteretic remanent magnetization ; Calibration ; Instrumentation ; Relative ; 04. Solid Earth::04.05. Geomagnetism::04.05.07. Rock magnetism ; 04. Solid Earth::04.05. Geomagnetism::04.05.08. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 100
    facet.materialart.
    Unknown
    Paleomagnetic constraints on the Plio-Pleistocene geodynamic evolution of the external central-northern Apennines (Italy) (2008)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We report on new paleomagnetic results obtained from 27 sites sampled in the Plio-Pleistocene sequences at the external front of the central-northern Apennines. Previous analyses of Miocene (Messinian) sediments indicated that the present shape of the northern Apenninic arc is due to the oroclinal bending of an originally straight belt oriented around N320° and that vertical axis rotations accompanied the migration of the thrust fronts toward the Adriatic foreland [F. Speranza et al., J. Geophys. Res. 102 (1997) 3153-3166]. We tried to provide new paleomagnetic constraints for the timing and rates of the oroclinal bending process during the Pliocene and the Pleistocene. The results suggest that CCW rotations observed in the northern part of the studied area are possibly younger than 3 Ma. No regional rotation is recorded in the Pliocene and Pleistocene sediments from the southern part of the study area, analogously to the Messinian sediments of the 'Acquasanta' domain of Speranza et al. [F. Speranza et al., J. Geophys. Res. 102 (1997) 3153-3166]. A local significant CCW rotation (23° ± 10°) is identified in the Early Pleistocene sediments that crop out along the Adriatic coast between Ascoli and Pescara, indicating differential motion of the thrust sheets. This rotation must be younger than 1.43 Ma.
    Description: Published
    Description: 243-257
    Description: 2.2. Laboratorio di paleomagnetismo
    Description: JCR Journal
    Description: open
    Keywords: paleomagnetism ; Apennines ; tectonics ; Pliocene ; Pleistocene ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...