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
  • 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics  (50)
  • 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous  (34)
  • American Geophysical Union  (45)
  • AGU  (17)
  • Geological Society of America  (12)
  • OGS
Collection
Keywords
Publisher
Years
  • 1
    facet.materialart.
    Unknown
    Gouge graphitization and dynamic fault weakening during the 2008 Mw 7.9 Wenchuan earthquake (2015)
    Geological Society of America
    Details
    Publication Date: 2024-03-20
    Description: The Longmenshan fault that ruptured during the 2008 Mw 7.9 Wenchuan (China) earthquake was drilled to a depth of 1200 m, and fault rocks including those in the 2008 earthquake slip zone were recovered at a depth of 575–595 m. We report laboratory strength measurements and microstructural observations from samples of slip zone fault rocks at deformation conditions expected for coseismic slip at borehole depths. Results indicate that the Longmenshan fault at this locality is extremely weak at seismic slip rates. In situ synchrotron X-ray diffraction analysis indicates that graphite was formed along localized slip zones in the experimental products, similar to the occurrence of graphite in the natural principal slip zone of the 2008 Wenchuan rupture. We surmise that graphitization occurred due to frictional heating of carbonaceous minerals. Because graphitization was associated with strong dynamic weakening in the experiments, we further infer that the Longmenshan fault was extremely weak at borehole depths during the 2008 Wenchuan earthquake, and that enrichment of graphite along localized slip zones could be used as an indicator of transient frictional heating during seismic slip in the upper crust.
    Description: Published
    Description: 47-50
    Description: 4T. Fisica dei terremoti e scenari cosismici
    Description: JCR Journal
    Description: reserved
    Keywords: Wenchuan ; drilling project ; Earthquakes ; Rock mechanics ; 04. Solid Earth::04.01. Earth Interior::04.01.04. Mineral physics and properties of rocks ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution ; 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)
  • 2
    facet.materialart.
    Unknown
    Rayleigh wave dispersion measurements reveal low-velocity zones beneath the new crust in the Gulf of California (2015)
    American Geophysical Union
    Details
    Publication Date: 2022-06-14
    Description: Rayleigh wave tomography provides images of the shallow mantle shear wave velocity structure beneath the Gulf of California. Low-velocity zones (LVZs) are found on axis between 26 and 50 km depth beneath the Guaymas Basin but mostly off axis under the other rift basins, with the largest feature underlying the Ballenas Transform Fault. We interpret the broadly distributed LVZs as regions of partial melting in a solid mantle matrix. The pathway for melt migration and focusing is more complex than an axis-centered source aligned above a deeper region of mantle melt and likely reflects the magmatic evolution of rift segments. We also consider the existence of solid lower continental crust in the Gulf north of the Guaymas Basin, where the association of the LVZs with asthenospheric upwelling suggests lateral flow assisted by a heat source. These results provide key constraints for numerical models of mantle upwelling and melt focusing in this young oblique rift.
    Description: Published
    Description: 1766–1774
    Description: 1T. Geodinamica e interno della Terra
    Description: JCR Journal
    Description: open
    Keywords: Low velocities in the Gulf upper mantle are interpreted as partial melting ; Partial melting under the Guaymas Basin and off axis of the other rift basins ; Lower crustal flow assisted by heat source in N Gulf near mantle upwelling ; 04. Solid Earth::04.01. Earth Interior::04.01.03. Mantle and Core dynamics ; 04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy ; 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)
  • 3
    facet.materialart.
    Unknown
    Effect of glass on the frictional behavior of basalts at seismic slip rates (2015)
    American Geophysical Union
    Details
    Publication Date: 2021-12-16
    Description: We performed 31 friction experiments on glassy basalts (GB) and glass-free basalts (GFB) at slip rates up to 6.5 m s−1 and normal stress up to 40 MPa (seismic conditions). Frictional weakening was associated to bulk frictional melting and lubrication. The weakening distance (Dw) was about 3 times shorter in GB than in GFB, but the steady state friction was systematically higher in GB than in GFB. The shorter Dw in GB may be explained by the thermal softening occurring at the glass transition temperature (Tg ~500°C), which is lower than the bulk melting temperature (Tm ~1250°C) of GFB. Postexperiment microanalyses suggest that the larger crystal fraction measured in GB melts results in the higher steady state friction value compared to the GFB melts. The effect of interstitial glass is to facilitate frictional instability and rupture propagation in GB with respect to GFB.
    Description: Published
    Description: 348-355
    Description: 4T. Fisica dei terremoti e scenari cosismici
    Description: JCR Journal
    Description: embargoed_20160201
    Keywords: Earthquakes ; Friction ; Basalts ; Interstitial glass ; 04. Solid Earth::04.01. Earth Interior::04.01.04. Mineral physics and properties of rocks ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones ; 04. Solid Earth::04.04. Geology::04.04.07. Rock geochemistry ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution ; 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)
  • 4
    facet.materialart.
    Unknown
    Quantifying volcanic ash dispersal and impact of the Campanian Ignimbrite super-eruption (2012)
    American Geophysical Union
    Details
    Publication Date: 2021-12-06
    Description: We apply a novel computational approach to assess, for the first time, volcanic ash dispersal during the Campanian Ignimbrite (Italy) super-eruption providing insights into eruption dynamics and the impact of this gigantic event. The method uses a 3D time-dependent computational ash dispersion model, a set of wind fields, and more than 100 thickness measurements of the CI tephra deposit. Results reveal that the CI eruption dispersed 250–300 km3 of ash over 3.7 million km2. The injection of such a large quantity of ash (and volatiles) into the atmosphere would have caused a volcanic winter during the Heinrich Event 4, the coldest and driest climatic episode of the Last Glacial period. Fluorine-bearing leachate from the volcanic ash and acid rain would have further affected food sources and severely impacted Late Middle-Early Upper Paleolithic groups in Southern and Eastern Europe.
    Description: Published
    Description: L10310
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: JCR Journal
    Description: restricted
    Keywords: Campanian Ignimbrire ; Campi Flegrei ; 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)
  • 5
    facet.materialart.
    Unknown
    Timing and magnitude of rotations in the frontal thrust systems of southwestern Sicily (2008)
    AGU
    Details
    Publication Date: 2021-09-08
    Description: We report new paleomagnetic and anisotropy of magnetic susceptibility (AMS) results from upper Tortonian to middle Pleistocene sediments which were deposited upon and adjacent to active thrust structures in southwestern Sicily. The data show that the Plio-Pleistocene sediments from the Belice and Menfi basins (covering the Saccense shelf limestones) underwent any internal shortening after the early Pleistocene (Santernian), as well as any net rotation. Sediments around this area (which overlie basinal Meso-Cenozoic successions) record systematic rotations: one upper Tortonian site to the west is ~30° counterclockwise rotated, while to the east, lower Pliocene to middle lower Pleistocene sites within the Gela Nappe domain show 25° to 56° clockwise (CW) rotations. These data show that the ductile basinal sediments were bent and rotated around the rigid Saccense carbonates during the thin-skinned southward propagation of the orogenic front. We document here that the coastal sediments from the southwestern Gela Nappe underwent both a post middle early Pleistocene ~30° CW rotation and a post middle Pleistocene E-W to ESE-WNW flattening (revealed by AMS). Our data then constrain to the late Pleistocene-Holocene the age of the last shortening episode occurring in the southwestern Gela Nappe front. Pleistocene rotations of similar amount also characterize the Sicanian domain, implying that it was incorporated in the Gela Nappe wedge during the recentmost episodes of deformation. This evidence allows us to better understand the very large (up to 114°) post Mesozoic rotations reported by Channell et al. [1980, 1990] for the Sicanian limestones, as related to both Miocene (or older?) deformational episodes and the Plio-Pleistocene evolution of the Gela Nappe.
    Description: Published
    Description: 1178-1197
    Description: JCR Journal
    Description: reserved
    Keywords: paleomagnetism ; tectonic rotations ; Sicily ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism ; 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)
  • 6
    facet.materialart.
    Unknown
    Mirror-like faults and power dissipation during earthquakes (2015)
    Geological Society of America
    Details
    Publication Date: 2021-05-17
    Description: Earthquakes occur along faults in response to plate tectonic movements, but paradoxically, are not widely recognized in the geological record, severely limiting our knowledge of earthquake physics and hampering accurate assessments of seismic hazard. Light-reflective (so-called mirror like) fault surfaces are widely observed geological features, especially in carbonate-bearing rocks of the shallow crust. Here we report on the occurrence of mirror-like fault surfaces cutting dolostone gouges in the Italian Alps. Using friction experiments, we demonstrate that the mirror-like surfaces develop only at seismic slip rates (∼1 m/s) and for applied normal stresses and sliding displacements consistent with those estimated on the natural faults. Under these experimental conditions, the frictional power density dissipated in the samples is comparable to that estimated for natural earthquakes (1–10 MW/m2). Our results indicate that mirror-like surfaces in dolostone gouges are a signature of seismic faulting, and can be used to estimate power dissipation during ancient earthquake ruptures.
    Description: Published
    Description: 1175-1178
    Description: 4T. Fisica dei terremoti e scenari cosismici
    Description: JCR Journal
    Description: reserved
    Keywords: Earthquakes ; Faults ; Carbonates ; Rock Mechanics ; 04. Solid Earth::04.01. Earth Interior::04.01.04. Mineral physics and properties of rocks ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution ; 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)
  • 7
    facet.materialart.
    Unknown
    Neotectonics and long-term seismicity in Europe and the Mediterranean region (2015)
    American Geophysical Union
    Details
    Publication Date: 2021-01-04
    Description: We present a neotectonic model of ongoing lithosphere deformation and a corresponding estimate of long-term shallow seismicity across the Africa-Eurasia plate boundary, including the eastern Atlantic, Mediterranean region, and continental Europe. GPS and stress data are absent or inadequate for the part of the study area covered by water. Thus, we opt for a dynamic model based on the stress-equilibrium equation; this approach allows us to estimate the long-term behavior of the lithosphere (given certain assumptions about its structure and physics) for both land and sea areas. We first update the existing plate model by adding five quasi-rigid plates (the Ionian Sea, Adria, Northern Greece, Central Greece, and Marmara) to constrain the deformation pattern of the study area. We use the most recent datasets to estimate the lithospheric structure. The models are evaluated in comparison with updated datasets of geodetic velocities and the most compressive horizontal principal stress azimuths. We find that the side and basal strengths drive the present-day motion of the Adria and Aegean Sea plates, whereas lithostatic pressure plays a key role in driving Anatolia. These findings provide new insights into the neotectonics of the greater Mediterranean region. Finally, the preferred model is used to estimate long-term shallow seismicity, which we retrospectively test against historical seismicity. As an alternative to reliance on incomplete geologic data or historical seismic catalogs, these neotectonic models help to forecast long-term seismicity, although requiring additional tuning before seismicity rates are used for seismic hazard purposes.
    Description: Published
    Description: 5311–5342
    Description: 1T. Geodinamica e interno della Terra
    Description: 2T. Tettonica attiva
    Description: 3T. Pericolosità sismica e contributo alla definizione del rischio
    Description: JCR Journal
    Description: open
    Keywords: Tectonics ; Earthquake rates ; 04. Solid Earth::04.02. Exploration geophysics::04.02.03. Heat flow ; 04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution ; 04. Solid Earth::04.06. Seismology::04.06.02. Earthquake interactions and probability ; 04. Solid Earth::04.07. Tectonophysics::04.07.01. Continents ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.04. Plate boundaries, motion, and tectonics ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress ; 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)
  • 8
    facet.materialart.
    Unknown
    High-speed imaging of Strombolian explosions: The ejection velocity of pyroclasts (2015)
    American Geophysical Union
    Details
    Publication Date: 2020-12-14
    Description: Explosive volcanic eruptions are defined as the violent ejection of gas and hot fragments from a vent in the Earth's crust. Knowledge of ejection velocity is crucial for understanding and modeling relevant physical processes of an eruption, and yet direct measurements are still a difficult task with largely variable results. Here we apply pioneering high-speed imaging to measure the ejection velocity of pyroclasts from Strombolian explosive eruptions with an unparalleled temporal resolution. Measured supersonic velocities, up to 405 m/s, are twice higher than previously reported for such eruptions. Individual Strombolian explosions include multiple, sub-second-lasting ejection pulses characterized by an exponential decay of velocity. When fitted with an empirical model from shock-tube experiments literature, this decay allows constraining the length of the pressurized gas pockets responsible for the ejection pulses. These results directly impact eruption modeling and related hazard assessment, as well as the interpretation of geophysical signals from monitoring networks.
    Description: INGV-DPC “V2” and “Paroxysm”, FIRB-MIUR “Research and Development of New Technologies for Protection and Defense of Territory from Natural Risks”, and FP7-PEOPLE-IEF-2008 – 235328 Projects
    Description: Published
    Description: L02301
    Description: 3V. Dinamiche e scenari eruttivi
    Description: JCR Journal
    Description: open
    Keywords: strombolian ; ejection velocity ; explosive eruption ; 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::04.08.06. 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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 9
    facet.materialart.
    Unknown
    Rheology of magmas with bimodal crystal size and shape distributions: Insights from analog experiments (2012)
    AGU
    Details
    Publication Date: 2020-12-14
    Description: Magmas in volcanic conduits commonly contain microlites in association with preexisting phenocrysts, as often indicated by volcanic rock textures. In this study, we present two different experiments that investigate the flow behavior of these bidisperse systems. In the first experiments, rotational rheometric methods are used to determine the rheology of monodisperse and polydisperse suspensions consisting of smaller, prolate particles (microlites) and larger, equant particles (phenocrysts) in a bubble‐free Newtonian liquid (silicate melt). Our data show that increasing the relative proportion of prolate microlites to equant phenocrysts in a magma at constant total particle content can increase the relative viscosity by up to three orders of magnitude. Consequently, the rheological effect of particles in magmas cannot be modeled by assuming a monodisperse population of particles. We propose a new model that uses interpolated parameters based on the relative proportions of small and large particles and produces a considerably improved fit to the data than earlier models. In a second series of experiments we investigate the textures produced by shearing bimodal suspensions in gradually solidifying epoxy resin in a concentric cylinder setup. The resulting textures show the prolate particles are aligned with the flow lines and spherical particles are found in well‐organized strings, with sphere‐depleted shear bands in high‐shear regions. These observations may explain the measured variation in the shear thinning and yield stress behavior with increasing solid fraction and particle aspect ratio. The implications for magma flow are discussed, and rheological results and textural observations are compared with observations on natural samples.
    Description: Published
    Description: Q07024
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: restricted
    Keywords: analog experiments ; crystal bearing ; polydisperse suspensions ; rheology ; 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)
  • 10
    facet.materialart.
    Unknown
    Coseismic recrystallization during shallow earthquake slip (2015)
    Geological Society of America
    Details
    Publication Date: 2020-11-26
    Description: Solidified frictional melts, or pseudotachylytes, remain the only unambiguous indicator of seismic slip in the geological record. However, pseudotachylytes form at 〉5 km depth, and there are many rock types in which they do not form at all. We performed low- to high-velocity rock friction experiments designed to impose realistic coseismic slip pulses on calcite fault gouges, and report that localized dynamic recrystallization may be an easy-to-recognize microstructural indicator of seismic slip in shallow, otherwise brittle fault zones. Calcite gouges with starting grain size 〈250 μm were confined up to 26 MPa normal stress using a purpose-built sample holder. Slip velocities were between 0.01 and 3.4 m s−1, and total displacements between 1 and 4 m. At coseismic slip velocities ≥0.1 m s−1, the gouges were cut by reflective principal slip surfaces lined by polygonal grains 〈1 μm in size. The principal slip surfaces were flanked by 〈300 μm thick layers of dynamically recrystallized calcite (grain size 1–10 μm) containing well-defined shape- and crystallographic-preferred orientations. Dynamic recrystallization was accompanied by fault weakening and thermal decomposition of calcite to CO2 + CaO. The recrystallized calcite aggregates resemble those found along the principal slip surface of the Garam thrust, South Korea, exhumed from 〈5 km depth. We suggest that intense frictional heating along the experimental and natural principal slip surfaces resulted in localized dynamic recrystallization, a microstructure that may be diagnostic of seismic slip in the shallow crust.
    Description: Published
    Description: 63-66
    Description: 4T. Fisica dei terremoti e scenari cosismici
    Description: JCR Journal
    Description: reserved
    Keywords: Rock mechanics ; shallow earthquales ; 04. Solid Earth::04.01. Earth Interior::04.01.04. Mineral physics and properties of rocks ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 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)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...