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  (9)
  • 04. Solid Earth::04.08. Volcanology::04.08.01. Gases  (6)
  • earthquakes  (3)
  • Greece
  • AGU  (7)
  • Copernicus  (2)
  • American Association for the Advancement of Science
  • 2010-2014  (9)
  • 1980-1984
  • 1965-1969
  • 1925-1929
Collection
  • Articles  (9)
Source
Keywords
Publisher
Years
  • 2010-2014  (9)
  • 1980-1984
  • 1965-1969
  • 1925-1929
  • 2005-2009  (15)
Year
  • 1
    facet.materialart.
    Unknown
    Excess volatiles supplied by mingling of mafic magma at an andesite arc volcano (2010)
    AGU
    Details
    Publication Date: 2021-04-07
    Description: We present the results of a study of volcanic gases at Soufrière Hills Volcano, Montserrat, which includes the first spectroscopic measurements of the major gas species CO2 and H2S at this volcano using a Multisensor Gas Analyzer System (MultiGAS) sensor. The fluxes of CO2 and H2S were 640–2750 t/d and 84–266 t/d, respectively, during July 2008, during a prolonged eruptive pause. The flux of CO2 is similar to estimates for the entire arc from previous geochemical studies, while the measured H2S flux significantly alters our interpretation of the sulphur budget for this volcano. The fluxes of both sulphur and carbon show considerable excesses over that which can be supplied by degassing of erupted magma. We demonstrate, using thermodynamic models and published constraints on preeruptive volatile concentrations, that the gas composition and fluxes are best modeled by mixing between (1) gases derived from isobaric quenching of mafic magma against cooler andesite magma at depth and (2) gases derived from shallower rhyolitic interstitial melt within the porpyritic andesite. The escape of deep‐derived gases requires pervasive permeability or vapor advection extending to several kilometers depth in the conduit and magma storage system. These results provide more compelling evidence for both the contribution of unerupted mafic magma to the volatile budget of this andesitic arc volcano and the importance of the intruding mafic magma in sustaining the eruption. From a broader perspective, this study illustrates the importance and role of underplating mafic magmas in arc settings. These magmas play an important role in triggering and sustaining eruptions and contribute in a highly significant way to the volatile budget of arc volcanoes.
    Description: Published
    Description: Q04005
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: restricted
    Keywords: magma degassing ; thermodynamics ; volcanic gases ; Soufriere Hills ; 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)
  • 2
    facet.materialart.
    Unknown
    Static stress drop associated with brittle slip events on exhumed faults. (2010)
    AGU
    Details
    Publication Date: 2017-04-04
    Description: We estimate the static stress drop on small exhumed strike-slip faults in the Lake Edison granodiorite of the central Sierra Nevada (California). The subvertical strike-slip faults were exhumed from 4 to 15 km depth and were chosen because they are exposed in outcrop along their entire tip-to-tip lengths of 8–12 m. Slip nucleated on joints and accumulated by crystal-plastic shearing (forming quartz mylonites from early quartz vein filling in joints) and successive brittle faulting (forming epidote-bearing cataclasites). The occurrence of thin, 300 mm wide, pseudotachylytes along some small faults throughout the study area suggests that some, if not all, of the brittle slip on the study area faults may have been seismic. We suggest that the contribution of brittle, cataclastic slip to the total slip along the studied cataclasite-bearing small faults may be estimated by the length of epidote-filled, rhombohedral dilatational jogs (rhombochasms) distributed quasi-periodically along the length of the faults. The interpretation that slip recorded by rhombochasms occurred in single events is based on evidence that (1) epidote crystals are randomly oriented and undeformed within the rhombochasm; (2) cataclasite in principal slip zones does not include clasts of previous cataclasite, and (3) rhombochasm lengths vary systematically along the length of the faults with slip maximum occurring near the fault center, tapering to the fault tips. We thereby constrain both the rupture length and slip. On the basis of these measurements, we calculate stress drops ranging over 90–250 MPa, i.e., one to two orders of magnitude larger than typical seismological estimates for earthquakes, but similar in magnitude to seismological estimates of small (〈M2) earthquakes from the San Andreas Fault Observatory at Depth (SAFOD). The slip events described in the present study occurred along small, deep-seated faults, and, given the calculated stress drops and observations that brittle faults exploited joints sealed by quartz-bearing mylonite, we conclude that these were ‘‘strong’’ faults.
    Description: Published
    Description: B02402
    Description: 3.1. Fisica dei terremoti
    Description: JCR Journal
    Description: reserved
    Keywords: earthquakes ; stress drops ; 04. Solid Earth::04.04. Geology::04.04.99. 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)
  • 3
    facet.materialart.
    Unknown
    Static chamber methane flux measurements in volcanic/geothermal areas: preliminary data from Sousaki and Nisyros (Greece) (2010)
    Copernicus
    Details
    Publication Date: 2017-04-04
    Description: Methane plays an important role in the Earth’s atmospheric chemistry and radiative balance being the second most important greenhouse gas after carbon dioxide. Methane is released to the atmosphere by a wide number of sources, both natural and anthropogenic, with the latter being twice as large as the former (IPCC, 2007). It has recently been established that significant amounts of geological methane, produced within the Earth’s crust, are currently released naturally into the atmosphere (Etiope, 2004). Active or recent volcanic/geothermal areas represent one of these sources of geological methane. But due to the fact that methane flux measurements are laboratory intensive, very few data have been collected until now and the contribution of this source has been generally indirectly estimated (Etiope et al., 2007). The Greek territory is geodynamically very active and has many volcanic and geothermal areas. Here we report on methane flux measurements made at two volcanic/geothermal systems along the South Aegean volcanic arc: Sousaki and Nisyros. The former is an extinct volcanic area of Plio-Pleistocene age hosting nowadays a low enthalpy geothermal field. The latter is a currently quiescent active volcanic system with strong fumarolic activity due to the presence of a high enthalpy geothermal system. Both systems have gas manifestations that emit significant amounts of hydrothermal methane and display important diffuse carbon dioxide emissions from the soils. New data on methane isotopic composition and higher hydrocarbon contents point to an abiogenic origin of the hydrothermal methane in the studied systems. Measured methane flux values range from –48 to 29,000 (38 sites) and from –20 to 1100 mg/mˆ2/d (35 sites) at Sousaki and Nisyros respectively. At Sousaki measurement sites covered almost all the degassing area and the diffuse methane output can be estimated in about 20 t/a from a surface of about 10,000 mˆ2. At Nisyros measurements covered the Stephanos and Kaminakia areas, which represent only a part of the entire degassing area. The two areas show very different methane degassing pattern with latter showing much higher flux values. Methane output can be estimated in about 0.25 t/a from an area of about 30,000 mˆ2 at Stephanos and about 1 t/a from an area of about 20,000 mˆ2 at Kaminakia. The total output from the entire geothermal system of Nisyros probably should not exceed 2 t/a.
    Description: Published
    Description: Vienna, Austria
    Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Description: open
    Keywords: methane output ; diffuse degassing ; volcanic/hydrothermal systems ; Greece ; 01. Atmosphere::01.01. Atmosphere::01.01.03. Pollution ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data ; 05. General::05.08. Risk::05.08.01. Environmental risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Poster session
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    Environmental impact of Mt. Etna’s degassing: volcanogenic trace elements bioaccumulation in two endemic plant species (Senecio aethnensis and Rumex aethnensis) (2010)
    Copernicus
    Details
    Publication Date: 2017-04-04
    Description: A biomonitoring survey, above tree line level, using two endemic species (Senecio aethnensis and Rumex aethnensis) was performed on Mt. Etna, in order to evaluate the dispersion and the impact of volcanic atmospheric emissions. Samples of leaves were collected in summer 2008 from 30 sites in the upper part of the volcano (1500- 3000 m a.s.l). Acid digestion of samples was carried out with a microwave oven, and 44 elements were analyzed by using plasma spectrometry (ICP-MS and ICP-OES). The highest concentrations of all investigated elements were found in the samples collected closest to the degassing craters, and in the downwind sector, confirming that the eastern flank of Mt. Etna is the most impacted by volcanic emissions. Leaves collected along two radial transects from the active vents on the eastern flank, highlight that the levels of metals decrease one or two orders of magnitude with increasing distance from the source. This variability is higher for volatile elements (As, Bi, Cd, Cs, Pb, Sb, Tl) than for more refractory elements (Al, Ba, Sc, Si, Sr, Th, U). The two different species of plants do not show significant differences in the bioaccumulation of most of the analyzed elements, except for lanthanides, which are systematically enriched in Rumex leaves. The high concentrations of many toxic elements in the leaves allow us to consider these plants as highly tolerant species to the volcanic emissions, and suitable for biomonitoring researches in the Mt. Etna area.
    Description: Published
    Description: Vienna, Austria
    Description: 4.4. Scenari e mitigazione del rischio ambientale
    Description: open
    Keywords: Mt. Etna ; biomonitoring ; Trace elements ; 01. Atmosphere::01.01. Atmosphere::01.01.03. Pollution ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data ; 05. General::05.08. Risk::05.08.01. Environmental risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Poster session
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    Unusually large magmatic CO2 gas emissions prior to a basaltic paroxysm (2010)
    AGU
    Details
    Publication Date: 2012-02-03
    Description: An edited version of this paper was published by AGU. Copyright (2010) American Geophysical Union.
    Description: The low‐intensity activity of basaltic volcanoes is occasionally interrupted by short‐lived but energetic explosions which, whilst frequently observed, are amongst the most enigmatic volcanic events in Nature. The combination of poorly understood and deep, challenging to measure, source processes make such events currently impossible to forecast. Here we report increases in quiescent degassing CO2 emissions (〉10,000 t/day) prior to a powerful explosive event on Stromboli volcano on 15 March 2007. We interpret such large CO2 flux as being sourced by passive gas leakage from a deeply (〉4 km) stored magma, whose depressurization, possibly caused by the onset of an effusive eruption on 28 February 2007, was the explosion trigger. Our observations suggest that continuous CO2 flux monitoring may allow anomalously large explosions to be accurately forecast at basaltic volcanoes.
    Description: Funding from INGV‐DPC project Paroxysm
    Description: Published
    Description: L17303
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: CO2, UV scanner, Stromboli ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    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
    Rough Faults, Distributed Weakening, and Off-Fault Deformation (2010)
    AGU
    Details
    Publication Date: 2017-04-04
    Description: We report systematic spatial variations of fault rocks along non-planar strike-slip faults 11 cross-cutting the Lake Edison Granodiorite, Sierra Nevada, California (Sierran wavy fault) and 12 Lobbia outcrops of the Adamello Batholith in the Italian Alps (Lobbia wavy fault). In the case of 13 the Sierran fault, pseudotachylyte formed at contractional fault bends, where it is found as thin 14 (1-2 mm) fault-parallel veins. Epidote and chlorite developed in the same seismic context as the 15 pseudotachylyte and are especially abundant in extensional fault bends. We argue that the 16 presence of fluids, as illustrated by this example, does not necessarily preclude the development 17 of frictional melt. In the case of the Lobbia fault, pseudotachylyte thickness varies along the 18 length of the fault, but the pseudotachylyte veins thicken and pool in extensional bends. We 19 conduct a quantitative analysis of fault roughness, microcrack distribution, stress, and friction 20 along the Lobbia fault. 21 Numerical modeling results show that opening in extensional bends and localized thermal 22 weakening in contractional bends counteract resistance encountered by fault waviness, resulting 23 in an overall weaker fault than suggested by the corresponding static friction coefficient. The 24 models also predict static stress redistribution around bends in the faults which are consistent 25 with distributions of microcracks, indicating significant elastic and inelastic strain energy is 26 dissipated into the wall rocks due to non-planar fault geometry. Together these observations suggest that damage and energy dissipation occurs along the entire non-planar fault during slip, 28 rather than being confined to the region close to the dynamically propagating crack tip.
    Description: Published
    Description: 3.1. Fisica dei terremoti
    Description: JCR Journal
    Description: open
    Keywords: earthquakes ; rutpure ; 04. Solid Earth::04.04. Geology::04.04.99. 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)
  • 7
    facet.materialart.
    Unknown
    CO2 degassing system of Stromboli volcano inferred by summit, peripheral and hydrothermal continuous measurements. (2010)
    AGU
    Details
    Publication Date: 2017-04-04
    Description: Stromboli is an open conduct volcano characterized by “Strombolian” activity. This activity is the result of a “delicate” dynamic equilibrium between continuous refilling of deep volatiles exsolved from the magma batch and superficial degassing. The volatiles, reaching the surface, interact with superficial fluids modifying peripheral and summit degassing processes. In particular, the main peripheral manifestations are represented by dissolved volatiles in the basal hydrothermal aquifer, as well as structurally controlled soil degassing at the lower parts of the volcanic edifice. Summit degassing is manifested by active (explosions from the conduct) and passive degassing (plume degassing from the conduct and diffuse soil degassing). During “normal” Strombolian activity this dynamic equilibrium allows the discharge of the volatiles in the atmosphere arriving from the depth. When the deep volatile flux increases, we observe that the system reacts by first increasing the diffuse volatile discharge from the superficial system. In fact, the result is the increase of Strombolian activity (frequency and energy of explosions due to the increase of the total volatiles pressure) and the increase of the total dissolved volatiles in the hydrothermal aquifer and soils anomalous flux. During overpressure of the plumbing system paroxistic activity is necessary to maintain the dynamic pressure equilibrium, allows to maintain the dynamic equilibrium between deep and superficial volatiles. In fact, through the opening of new fractures and consecutive lava flow or by major explosions and paroxysms the system decreases the total pressure of volatiles and restores the dynamic equilibrium of the Stromboli plumbing system. On the basis of the experiences acquired during the last two eruptions (2002-2003 and 2007) we improved our geochemical monitoring network by installing new equipments for monitoring, continuously, selected fluid manifestations located on the peripheral areas. In particular, we installed two automatic equipments for measuring dissolved CO2 in the thermal wells located in the N-E side of Stromboli (Stromboli village). In this way we covered wider area of fluid degassing of Stromboli volcano to better understand the relationships between the degassing regimes of the summit and basal hydrothermal systems.
    Description: Published
    Description: San Francisco CA, USA
    Description: 2.4. TTC - Laboratori di geochimica dei fluidi
    Description: open
    Keywords: CO2 flux ; Volcano monitoring ; Stromboli ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Poster session
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    Hydrogen in the gas plume of an open‐vent volcano, Mount Etna, Italy (2011)
    AGU
    Details
    Publication Date: 2017-04-04
    Description: We report here on the first hydrogen determinations in the volcanic gas plume of Mount Etna, in Italy, which we obtained during periodic field surveys on the volcano’s summit area with an upgraded MultiGAS. Using a specific (EZT3HYT) electrochemical sensor, we resolved H2 concentrations in the plume of 1–3 ppm above ambient (background) atmosphere and derived H2‐SO2 and H2‐H2O plume molar ratios of 0.002–0.044 (mean 0.013) and 0.0001–0.0042 (mean 0.0018), respectively. Taking the above H2‐SO2 ratios in combination with a time‐averaged SO2 flux of 1600 Gg yr−1, we evaluate that Etna contributes a time‐averaged H2 flux of ∼0.65 Gg yr−1, suggesting that the volcanogenic contribution to the global atmospheric H2 budget (70,000–100,000 Gg yr−1) is marginal. We also use our observed H2‐H2O ratios to propose that Etna’s passive plume composition is (at least partially) representative of a quenched (temperatures between 750°C and 950°C) equilibrium in the gas‐magma system, at redox conditions close to the nickel‐nickel oxide (NNO) mineral buffer. The positive dependence between H2‐SO2, H2‐H2O, and CO2‐SO2 ratios suggests that H2 is likely supplied (at least in part) by deeply rising CO2‐rich gas bubbles, fluxing through a CO2‐depleted shallow conduit magma.
    Description: Published
    Description: B10204
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: 2.4. TTC - Laboratori di geochimica dei fluidi
    Description: JCR Journal
    Description: restricted
    Keywords: Hydrogen ; Mount Etna ; Open-vent volcano ; plume ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 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)
  • 9
    facet.materialart.
    Unknown
    Static stress drop as determined from geodetic strain rates and statistical seismicity (2011)
    AGU
    Details
    Publication Date: 2017-04-04
    Description: Accepted for publication in Journal of Geophysical Researches. Copyright (2010) American Geophysical Union
    Description: Two critical items in the energetic budget of a seismic province are the strain rate, which is measured geodetically on the Earth’s surface, and the yearly number of earthquakes exceeding a given magnitude. Our study is based on one of the most complete and recent seismic catalogs of Italian earthquakes and on the strain rate map implied by a multi-year velocity solution for permanent GPS stations. For 36 homogeneous seismic zones, we used the appropriate Gutenberg Richter relation based on the seismicity catalog to estimate a seismic strain rate, which is the strain rate associated with the mechanical work due to a co-seismic displacement. The volume storing most of the elastic energy is associated with the long-term deformation of each seismic zone, and therefore, the seismic strain rate is inversely proportional to the static stress drop. The GPS-derived strain rate for each seismic zone limits the corresponding seismic strain rate, and an upper bound for the average stress drop is estimated. These results demonstrated that the implied regional static stress drop ranged from 0.1 to 5.7 MPa for catalog earthquakes in the moment magnitude range [4.5–7.3]. These results for stress drop are independent of the “a” and “b” regional parameters and heat flow but are very sensitive to the assumed maximum magnitude of a seismic province. The data do not rule out the hypothesis that the stress drop positively correlates with the time elapsed after the largest earthquake recorded in each seismic zone.
    Description: The research was supported by Project S1 2007-2009 of Istituto Nazionale di Geofisica e Vulcanologia and Dipartimento della Protezione Civile, Rome.
    Description: In press
    Description: 1.9. Rete GPS nazionale
    Description: 3.1. Fisica dei terremoti
    Description: 4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale
    Description: JCR Journal
    Description: open
    Keywords: earthquakes ; seismic hazard ; geodesy ; b-value ; 04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes ; 04. Solid Earth::04.01. Earth Interior::04.01.05. Rheology ; 04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations ; 04. Solid Earth::04.03. Geodesy::04.03.06. Measurements and monitoring ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones
    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...