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  • 04. Solid Earth::04.04. Geology::04.04.09. Structural geology  (8)
  • Wave propagation  (7)
  • 04. Solid Earth::04.04. Geology::04.04.04. Marine geology
  • Palaeozoic basement
  • Wiley-Blackwell  (10)
  • Wiley  (7)
  • American Physical Society
  • 2010-2014  (17)
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  • 1
    Publikationsdatum: 2024-05-09
    Beschreibung: Episodic gas seepage occurs at the seafloor in the Gulf of Izmit (Sea of Marmara, NW Turkey) along the submerged segment of the North Anatolian Fault (NAF), which ruptured during the 1999 Mw7.4 Izmit earthquake, and caused tectonic loading of the fault segment in front of the Istanbul metropolitan area. In order to study gas seepage and seismic energy release along the NAF, a multiparametric benthic observatory (SN-4) was deployed in the gulf at the western end of the 1999 Izmit earthquake rupture, and operated for about 1 yr at 166 m water depth. The SN-4 payload included a three-component broad-band seismometer, as well as gas and oceanographic sensors. We analysed data collected continuously for 161 d in the first part of the experiment, from 2009 October to 2010 March. The main objective of our work was to verify whether tectonic deformation along the NAF could trigger methane seepage. For this reason, we considered only local seismicity, that is, within 100 km from the station. No significant (ML ≥ 3.6) local earthquakes occurred during this period; on the other hand, the seismometer recorded high-frequency SDEs (short duration events), which are not related to seismicity but to abrupt increases of dissolved methane concentration in the sea water that we called MPEs (methane peak events). Acquisition of current velocity, dissolved oxygen, turbidity, temperature and salinity, allowed us to analyse the local oceanographic setting during each event, and correlate SDEs to episodic gas discharges from the seabed. We noted that MPEs are the result of such gas releases, but are detected only under favourable oceanographic conditions. This stresses the importance of collecting long-term multiparametric time-series to address complex phenomena such as gas and seismic energy release at the seafloor. Results from the SN-4 experiment in the Sea of Marmara suggest that neither low-magnitude local seismicity, nor regional events affect intensity and frequency of gas flows from the seafloor.
    Beschreibung: Published
    Beschreibung: 850-866
    Beschreibung: 1T. Geodinamica e interno della Terra
    Beschreibung: 3A. Ambiente Marino
    Beschreibung: 7A. Geofisica di esplorazione
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Time-series analysis ; Seismicity and tectonics ; Broad-band seismometers ; multiparametric seafloor observatory ; Izmit Gulf ; Sea of Marmara ; gas seepage ; 03. Hydrosphere::03.04. Chemical and biological::03.04.05. Gases ; 04. Solid Earth::04.04. Geology::04.04.04. Marine geology ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 2
    Publikationsdatum: 2017-04-04
    Beschreibung: Local and regional seismicity jointly recorded by two dense small aperture arrays, one installed at surface and one at 1.3 km depth, constitutes an interesting data set useful for coda observations. Applying array techniques to earthquakes recorded at the two arrays we measure slowness, backazimuth and correlation coefficient of the coherent coda wave signals in five frequency bands in the range 1–10 Hz. Slowness distributions show marked differences between surface and underground, with slow signals at surface (slowness greater than 1.0 s km−1) that are not observed underground. We interpret these coherent signals as surface waves produced by the interaction of body waves with the free surface characterized by rough topography. The backazimuth values measured in the frequency bands centred at 1.5 and 3 Hz are almost uniformly distributed between 0 and 360◦, while those measured at higher frequencies show different distributions between surface and underground. On the contrary, the earthquake envelopes show very similar coda shapes between surface and underground recordings, with an almost constant coda-amplitude ratio (between 4 and 8) in a wide frequency range.
    Beschreibung: Published
    Beschreibung: 367-371
    Beschreibung: 1.1. TTC - Monitoraggio sismico del territorio nazionale
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Coda waves ; Wave scattering and diffraction ; Wave propagation ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Publikationsdatum: 2017-04-04
    Beschreibung: In this work, we present regional maps of the inverse intrinsic quality factor (Qi −1), the inverse scattering quality factor (Qs −1) and total inverse quality factor (Qt −1) for the volcanic environment of Deception Island (Antarctica). Our attenuation study is based on diffusion approximation, which permits us to obtain the attenuation coefficients for every single couple source-receiver separately. The data set used in this research is derived from an active seismic experiment using more than 5200 offshore shots (air guns) recorded at 32 onshore seismic stations and four ocean bottom seismometers. To arrive at a regional distribution of these values, we used a new mapping technique based on a Gaussian space probability function. This approach led us to create ‘2-D probabilistic maps’ of values of intrinsic and scattering seismic attenuation. The 2-D tomographic images confirm the existence of a high attenuation body below an inner bay of Deception Island. This structure, previously observed in 2-D and 3-D velocity tomography of the region, is associated with a massive magma reservoir. Magnetotelluric studies reach a similar interpretation of this strong anomaly. Additionally, we observed areas with lower attenuation effects that bear correlation with consolidated structures described in other studies and associated with the crystalline basement of the area. Our calculations of the transport mean-free path and absorption length for intrinsic attenuation gave respective values of ≈950 m and 5 km, which are lower than the values obtained in tectonic regions or volcanic areas such as Tenerife Island. However, as observed in other volcanic regions, our results indicate that scattering effects dominate strongly over the intrinsic attenuation.
    Beschreibung: This work has been partially supported by the Spanish project Ephestos, CGL2011–29499-C02–01, by the EU project EC-FP7 MEDiterranean SUpersite Volcanoes (MED-SUV), by the Basque Government researcher training program BFI09.277 and by the Regional project ‘Grupo de Investigaci´on en Geof´ısica y Sismolog´ıa de la Junta de Andaluc´ıa, RNM104.’ Edoardo del Pezzo was partly supported by DPC-INGV projects UNREST SPEED and V2 (Precursori).
    Beschreibung: Published
    Beschreibung: 1957-1969
    Beschreibung: 3.1. Fisica dei terremoti
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Seismic attenuation; ; Seismic tomography ; Volcano seismology ; Wave scattering and diffraction ; Wave propagation ; 04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 4
    Publikationsdatum: 2017-04-04
    Beschreibung: This article has been accepted for publication in Geophysical Journal International ©: The Authors 2003. Published by Oxford University Press on behalf of The Royal Astronomical Society. All rights reserved.
    Beschreibung: In this study, we modify and extend a data analysis technique to determine the stress orientations between data clusters by adding an additional constraint governing the probability algorithm. We apply this technique to produce a map of the maximum horizontal compressive stress (S_Hmax) orientations in the greater European region (including Europe, Turkey and Mediterranean Africa). Using the World Stress Map dataset release 2008, we obtain analytical probability distributions of the directional differences as a function of the angular distance, θ. We then multiply the probability distributions that are based on pre-averaged data within θ〈3° of the interpolation point and determine the maximum likelihood estimate of the S_Hmax orientation. At a given distance, the probability of obtaining a particular discrepancy decreases exponentially with discrepancy. By exploiting this feature observed in the World Stress Map release 2008 dataset, we increase the robustness of our S_Hmax determinations. For a reliable determination of the most likely S_Hmax orientation, we require that 90% confidence limits be less than ±60° and a minimum of three clusters, which is achieved for 57% of the study area, with small uncertainties of less than ±10° for 7% of the area. When the data density exceeds 0.8×10^-3 data/km2, our method provides a means of reproducing significant local patterns in the stress field. Several mountain ranges in the Mediterranean display 90° changes in the S_Hmax orientation from their crests (which often experience normal faulting) and their foothills (which often experience thrust faulting). This pattern constrains the tectonic stresses to a magnitude similar to that of the topographic stresses.
    Beschreibung: This work was supported by the DPC-INGV 2008-2010 S1 project, the EU-FP7 project “Seismic Hazard Harmonization in Europe” (SHARE; Grant agreement no. 226967), and project MIUR-FIRB "Abruzzo" (code: RBAP10ZC8K_003).
    Beschreibung: Published
    Beschreibung: 3.1. Fisica dei terremoti
    Beschreibung: 3.3. Geodinamica e struttura dell'interno della Terra
    Beschreibung: 4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale
    Beschreibung: JCR Journal
    Beschreibung: partially_open
    Schlagwort(e): Neotectonics ; Seismicity and tectonics ; Fractures and faults ; Intra-plate processes ; Plate motions ; Dynamics: gravity and tectonics ; 04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress ; 05. General::05.02. Data dissemination::05.02.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 5
    Publikationsdatum: 2017-04-04
    Beschreibung: We used the SBAS DInSAR analysis technique to estimate the interseismic deformation along the western part of the Doruneh fault system (DFS), northeastern Iran. We processed 90 ENVISAT images from four different frames from ascending and descending orbits. Three of the ground velocity maps show a significant interseismic signal. Using a simple dislocation approach we model 2-D velocity profiles concerning three InSAR data set relative to the western part of the DFS, obtaining a good fit to the observations. The resulting model indicates that a slip rate of ∼5mmyr−1 accumulates on the fault below 10 km depth, and that in its western sector the Doruneh fault is not purely strike-slip (left-lateral) as in its central part, but shows a significant thrust component. Based on published geological observations, and assuming that all interseismic deformation is recovered with a single event, we can estimate a characteristic recurrence interval between 630 and 1400 yr.
    Beschreibung: Published
    Beschreibung: 622-628
    Beschreibung: 1.10. TTC - Telerilevamento
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Image processing; Satellite geodesy; Seismic cycle; Radar interferometry; Seismicity and tectonics; Continental tectonics: strike-slip and transform. ; 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::04.03. Geodesy::04.03.07. Satellite geodesy ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics ; 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)
    Materialart: article
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  • 6
    Publikationsdatum: 2022-05-24
    Beschreibung: This article focuses on the Montello thrust system in the Eastern Southern Alps as a potential seismogenic source. This system is of particular interest because of its lack of historical seismicity. Nevertheless, the system is undergoing active deformation. We developed a finite-element model using visco-elasto-plastic rheology. The free parameters of the model (essentially, the locking status of the three thrusts included in the study), were constrained by matching the observed horizontal GPS and vertical levelling data. We show that the amount of interseismic fault locking, and thus the seismic potential, is not necessarily associated with the fastest-slipping faults. More specifically, the locked Bassano thrust has a greater seismic potential than the freely slipping Montello thrust. The findings suggest that faults with subtle evidence of Quaternary activity should be carefully considered when creating seismic hazard maps.
    Beschreibung: Published
    Beschreibung: 221-227
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: 3.3. Geodinamica e struttura dell'interno della Terra
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): interseismic deformation ; Montello thrust ; Southern Alps ; 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::04.04. Geology::04.04.09. Structural geology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 7
    Publikationsdatum: 2017-04-04
    Beschreibung: We present the first application of a time reverse location method in a volcanic setting, for a family of long-period (LP) events recorded on Mt Etna. Results are compared with locations determined using a full moment tensor grid search inversion and cross-correlation method. From 2008 June 18 to July 3, 50 broad-band seismic stations were deployed on Mt Etna, Italy, in close proximity to the summit. Two families of LP events were detected with dominant spectral peaks around 0.9 Hz. The large number of stations close to the summit allowed us to locate all events in both families using a time reversal location method. The method involves taking the seismic signal, reversing it in time, and using it as a seismic source in a numerical seismic wave simulator where the reversed signals propagate through the numerical model, interfere constructively and destructively, and focus on the original source location. The source location is the computational cell with the largest displacement magnitude at the time of maximum energy current density inside the grid. Before we located the two LP families we first applied the method to two synthetic data sets and found a good fit between the time reverse location and true synthetic location for a known velocity model. The time reverse location results of the two families show a shallow seismic region close to the summit in agreement with the locations using a moment tensor full waveform inversion method and a cross-correlation location method.
    Beschreibung: Published
    Beschreibung: 452-462
    Beschreibung: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Volcano seismology ; Computational seismology ; Wave propagation ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 8
    Publikationsdatum: 2017-04-04
    Beschreibung: We investigate shear wave polarization in the Hayward fault zone near Niles Canyon, Fremont, CA. Waveforms of 12 earthquakes recorded by a seven-accelerometer seismic array around the fault are analysed to clarify directional site effects in the fault damage zone. The analysis is performed in the frequency domain through H/V spectral ratios with horizontal components rotated from 0◦ to 180◦, and in the time domain using the eigenvectors and eigenvalues of the covariance matrix method employing three component records. The near-fault ground motion tends to be polarized in the horizontal plane. At two on-fault stations where the local strike is N160◦, ground motion polarization is oriented N88 ± 19◦ and N83 ± 32◦, respectively. At a third on-fault station, the motion is more complex with horizontal polarization varying in different frequency bands. However, a polarization of N86 ± 7◦, similar to the results at the other two on-fault stations, is found in the frequency band 6–8 Hz. The predominantly high-angle polarization from the fault strike at the Hayward Fault is consistent with similar results at the Parkfield section of the San Andreas Fault and the Val d’Agri area (a Quaternary extensional basin) in Italy. In all these cases, comparisons of the observed polarization directions with models of fracture orientation based on the fault movement indicate that the dominant horizontal polarization is near-orthogonal to the orientation of the expected predominant cracking direction. The results help to develop improved connections between fault mechanics and near-fault ground motion.
    Beschreibung: Published
    Beschreibung: 1255–1272
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Earthquake ground motions. ; Interface waves ; Site effects ; Wave propagation ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 9
    Publikationsdatum: 2020-02-24
    Beschreibung: Integration of geologic, geomorphologic and seismologic data sets is used to reconstruct the recent tectonic evolution and active deformation pattern in the Val d’Agri area, located in the seismically active axial sector of the Southern Apennines (Italy). The western portion of the Apennines thrust belt has been affected by Pliocene–Quaternary extension during easterly roll-back and crustal delamination of the Adriatic slab. The bulk of Quaternary extension has been accommodated bySW-dipping oblique and normal faults,which have attained mature morphologic and structural features and, nowadays, separate mountain ranges from intermontane basins. However, in the present seismogenic belt, coseismic faulting locally occurs on NE-dipping structures, which might cut the inherited Pleistocene landscape. In theVal d’Agri basin, in spite of the large Early–Middle Pleistocene, displacement occurred on SW-dipping faults bordering its eastern flank, our investigations show that the recent basin evolution has been controlled by a NE-dipping fault system (Monti della Maddalena fault system, MMFS). This fault system cuts across the Monti della Maddalena range, west of the Agri valley and has not yet created an evident tectonic landscape. Notwithstanding, fault motion since the Middle Pleistocene might explain geomorphologic and hydrographic anomalies of the Agri river and its valley, where fault-controlled subsidence has captured the river course and produced an aggrading plain within a regional uplift context. Recent and ongoing motion is documented by fault scarplets in loose deposits, 14C ages of palaeosols and the spatial relation with low to moderate instrumental seismicity. Results from fault kinematic analysis are compatible with fault-plane solutions of local and regional seismic events, and indicate ∼NE–SW oriented extension. Recognition of the MMFS as a potential seismogenic fault increases the longitudinal extent of the NE-dipping, morphologically immature seismic sources in the Southern Apennines and argues against the range-bounding fault model for active extension in the region. The regional size of the NE-dipping seismogenic belt may result from impingement of a mantle wedge beneath the Apenninic chain and possibly track the external front of crustal delamination.
    Beschreibung: Published
    Beschreibung: 591-609
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): active tectonics ; crustal deformation ; earthquakes ; geomorphology ; normal faulting ; Southern Italy ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 10
    Publikationsdatum: 2017-04-04
    Beschreibung: In the northern Apennines, the Palaeozoic basement involved in the Late Oligocene–Middle Miocene nappe stack contains metamorphic units for which hypothetical ages have been assigned on the basis of lithological correlations with the Palaeozoic formations of the Variscan chain in Sardinia. This uncertainty concerning the age poses limitations to reconstructing the Palaeozoic stratigraphy, defining the Alpine and pre-Alpine histories and correlations with other domains of the Variscan chain. We present the UPb age of detrital zircon and the 40Ar39Ar age of metamorphic muscovite for the Calamita Schist and Ortano Porphyroid, two metamorphic units of undetermined Palaeozoic age cropping out in the eastern Elba Island. The radioisotopic data allows us to: (i) define the Early Carboniferous and Middle Ordovician ages for the Calamita Schist and Ortano Porphyroid, respectively, as well as their derivation (flysch deposit and magmatic rocks); (ii) pose some constraints concerning their alpine tectonic and metamorphic histories. These new data generate a more precise reconstruction of the Palaeozoic sequence in the northern Apennines, and they document that the Palaeozoic basement involved in the alpine deformation underwent internal stacking with an inversion of the original sequence. Copyright © 2010 John Wiley & Sons, Ltd.
    Beschreibung: Published
    Beschreibung: 288-310
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: 3.3. Geodinamica e struttura dell'interno della Terra
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): northern Apennines ; Palaeozoic basement ; U-Pb zircon ; 40Ar-39Ar muscovite ; 04. Solid Earth::04.04. Geology::04.04.02. Geochronology ; 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)
    Materialart: article
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  • 11
    Publikationsdatum: 2021-06-08
    Beschreibung: We investigated the high frequency attenuation of S-waves in Southeastern Alps and Northern External Dinarides using waveforms from 331 earthquakes (3.0〈 Mw〈 6.5). The spectral decay parameter, k, was computed using 1345 three component high quality records, collected by the Italian Strong Motion Network (RAN) and by the Short-Period Seismometric Network of North-Eastern Italy (NEI) in the period 1976-2007. Weak motion data from 11 stations of the NEI network and strong motion data collected by 5 accelerometers of the RAN were analyzed. The k parameter was estimated in the 0-250 Km distance range, in a frequency band extending from the corner frequency of the event up to 25 or 45 Hz, using the amplitude acceleration Fourier spectra of S-waves. The observed record-to-record variability of k was modeled by applying a generalized inversion procedure, using both parametric and non-parametric approaches. Our results evidence that k is independent on earthquake size, while it shows both site and distance dependence. Stations of the NEI network present the same increase of k with epicentral distance, Re, and show values of the zero-distance k parameter, k0(S), between 0.017 and 0.053 s. For the whole region, the k increase with distance can be described through a linear model with slope dk/dRe = (1.4±0.1)x10^(-4) s/Km. Assuming an average S-wave velocity, 〈Vs〉=3.34 Km/s between 5 and 15 Km depth, we estimate an average frequency independent quality factor, 〈Qi〉=2140, for the corresponding crustal layer. The non-parametric approach evidences a weak positive concavity of the curve that describes the k increase with Re at about 90 Km distance. This result can be approximated through a piecewise linear function with slopes of 1.0x10^(-4) s/Km and 1.7x10^(-4) s/Km, in accordance with a three layers model where moving from the intermediate to the bottom layer both 〈Qi〉 and 〈Vs〉 decrease. Two regional dependences were found: data from earthquakes located westward to the NEI network evidence weaker attenuation properties, probably because of S-wave reflections from different part of the Moho discontinuity under the eastern Po Plain, at about 25-30 Km depth, while earthquakes located eastward (in western Slovenia), where the Moho deepens up to 45-50 Km, evidence a higher attenuation. Moreover, the k estimates obtained with data from earthquakes located in the area of the 1998 (Mw=5.7) and 2004 (Mw=5.2) Kobarid events are 0.017 s higher than the values predicted for the whole region, probably because of the high level of fracturing that characterizes fault zones. The comparison between measured and theoretical values of k, computed at a few stations with available S-wave velocity profiles, reveals that the major contribution to the total k0(S) is due to the sedimentary column (from surface to 800 m depth). The hard rock section contribution is limited to 0.005 s, in accordance with a maximum contribution of 0.010 s predicted by the non-parametric inversion.
    Beschreibung: Published
    Beschreibung: 1393-1416
    Beschreibung: 3.3. Geodinamica e struttura dell'interno della Terra
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Earthquake source observations ; Body waves ; Seismic attenuation ; Site effects ; Wave propagation ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 12
    Publikationsdatum: 2017-04-04
    Beschreibung: We analyzed a broad region around L’Aquila in search of seismogenic faults similar to that responsible for the 6 April 2009 earthquake (Mw 6.3). Having the lessons learned from this earthquake in mind, we focused on adjacent areas displaying similar morphotectonic, geological and structural evidence. The basin running from Barisciano to Civitaretenga-Navelli, notably located near the southeastern edge of the 2009 aftershock pattern, appears to be one of such areas. We collected morphotectonic and structural data indicating that this basin is underlain by a major active normal fault (San Pio Fault). All the observations are very much reminiscent of the morphotectonic, geological and structural setting of area struck by the L’Aquila earthquake, suggesting that the newly identified fault has the potential for a Mw 6.2-6.4 shock.
    Beschreibung: Published
    Beschreibung: Pages: 108–115
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: JCR Journal
    Beschreibung: partially_open
    Schlagwort(e): Seismotectonics ; Morphotectonics ; Active fault ; San Pio basin ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 13
    Publikationsdatum: 2017-04-04
    Beschreibung: We reply to a comment by Messina et al., who strongly criticized our paper on the San Pio Fault, by showing that in areas of complex geology such as the central Apennines, where the current tectonic setting results from the superposition of different tectonic regimes, the equation: “most visible active fault = major seismogenic fault” can be misleading.
    Beschreibung: Published
    Beschreibung: 421-423
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Seismotectonics ; morphotectonics ; active fault ; San Pio basin ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 14
    Publikationsdatum: 2017-04-04
    Beschreibung: In the northern Apennines, the Palaeozoic basement involved in the Late Oligocene–Middle Miocene nappe stack contains metamorphic units for which hypothetical ages have been assigned on the basis of lithological correlations with the Palaeozoic formations of the Variscan chain in Sardinia. This uncertainty concerning the age poses limitations to reconstructing the Palaeozoic stratigraphy, defining the Alpine and pre-Alpine histories and correlations with other domains of the Variscan chain. We present the U-Pb age of detrital zircon and the 40Ar-39Ar age of metamorphic muscovite for the Calamita Schist and Ortano Porphyroid, two metamorphic units of undetermined Palaeozoic age cropping out in the eastern Elba Island. The radioisotopic data allows us to: (i) define the Early Carboniferous and Middle Ordovician ages for the Calamita Schist and Ortano Porphyroid, respectively, as well as their derivation (flysch deposit and magmatic rocks); (ii) pose some constraints concerning their alpine tectonic and metamorphic histories. These new data generate a more precise reconstruction of the Palaeozoic sequence in the northern Apennines, and they document that the Palaeozoic basement involved in the alpine deformation underwent internal stacking with an inversion of the original sequence.
    Beschreibung: In press
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: 3.3. Geodinamica e struttura dell'interno della Terra
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): northern Apennines ; Palaeozoic basement ; U-Pb zircon ; 40Ar-39Ar muscovite ; 04. Solid Earth::04.04. Geology::04.04.02. Geochronology ; 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)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 15
    Publikationsdatum: 2017-04-04
    Beschreibung: We investigate in detail the crustal layering of the ‘Val di Chiana Basin’ (Northern Apennines, Tuscany, Italy) through receiver functions and seismic anisotropy with hexagonal symmetry. The teleseismic data set is recorded in correspondence of a typical foreland basin resulting by the progressive eastward retreat of a regional-scale subduction zone trapped between two continents. We study the azimuthal variations of the computed and binned receiver functions associated to a harmonic angular analysis to emphasize the presence of the dipping and the anisotropic structures. The resulting S-wave velocity model shows interesting and new results for this area that we discuss in a regional geodynamic contest contributing to the knowledge of the structure of the forearc of the subduction zone. A dipping interface (N192°E strike, 18° dip) has been revealed at about 1.5 km depth, that separates the basin sediments and flysch from the carbonates and evaporites. Moreover, we interpret the two upper-crust anisotropic layers (at about 6 and 17 km depth) as the Hercynian Phyllites and Micaschists, of the Metamorphic Tuscan Basement. At relatively shallow depths, the presence of these metamorphic rocks causes the seismic anisotropy in the upper crust. The presence of shallow anisotropic layers is a new and interesting feature, first revealed in the study area. Beneath the crust–mantle transition (Moho), located about 28 km depth, our analysis reveals a 7-km-thick anisotropic layer.
    Beschreibung: Published
    Beschreibung: 545-556
    Beschreibung: 3.3. Geodinamica e struttura dell'interno della Terra
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Seismic anisotopy ; Computational Seismology ; Wave propagation ; Subduction zone process ; Crustal structure ; Europe ; 04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 16
    Publikationsdatum: 2017-04-04
    Beschreibung: We present the first application of a time reverse location method in a volcanic setting, for a family of long-period (LP) events recorded on Mt Etna. Results are compared with locations determined using a full moment tensor grid search inversion and cross-correlation method. From 2008 June 18 to July 3, 50 broad-band seismic stations were deployed on Mt Etna, Italy, in close proximity to the summit. Two families of LP events were detected with dominant spectral peaks around 0.9 Hz. The large number of stations close to the summit allowed us to locate all events in both families using a time reversal location method. The method involves taking the seismic signal, reversing it in time, and using it as a seismic source in a numerical seismic wave simulator where the reversed signals propagate through the numerical model, interfere constructively and destructively, and focus on the original source location. The source location is the computational cell with the largest displacement magnitude at the time of maximum energy current density inside the grid. Before we located the two LP families we first applied the method to two synthetic data sets and found a good fit between the time reverse location and true synthetic location for a known velocity model. The time reverse location results of the two families show a shallow seismic region close to the summit in agreement with the locations using a moment tensor full waveform inversion method and a cross-correlation location method.
    Beschreibung: In press
    Beschreibung: (11)
    Beschreibung: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Volcano seismology ; Computational seismology ; Wave propagation ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 17
    Publikationsdatum: 2017-04-04
    Beschreibung: Stromboli is a 3000 m high island volcano, rising to 900 m above sea-level. It is the most active volcano of the Aeolian Archipelago in the Tyrrhenian Sea (Italy). Major, large volume (1 km3) sector collapses, four occurring in the last 13 kyr, have played an important role in shaping the north-western flank (Sciara del Fuoco) of the volcano, potentially generating a high-risk tsunami hazard for the Aeolian Islands and the Italian coast. However, smaller volume, partial collapses of the Sciara del Fuoco have been shown to be more frequent tsunami-generating events. One such event occurred on 30 December 2002, when a partial collapse of the north-western flank of the island took place. The resulting landslide generated 10 m high tsunami waves that impacted the island. Multibeam bathymetry, side-scan sonar imaging and visual observations reveal that the landslide deposited 25 to 30 × 106 m3 of sediment on the submerged slope offshore from the Sciara del Fuoco. Two contiguous main deposit facies are recognized: (i) a chaotic, coarse-grained (metre-sized to centimetre-sized clasts) deposit; and (ii) a sand deposit containing a lower, cross-bedded sand layer and an upper structureless pebbly sand bed capped by sea floor ripple bedforms. The sand facies develops adjacent to and partially overlying the coarse deposits. Characteristics of the deposits suggest that they were derived from cohesionless, sandy matrix density flows. Flow rheology and dynamics led to the segregation of the density flow into sand-rich and clast-rich regions. A range of density flow transitions, both in space and in time, caused principally by particle concentration and grain-size partitioning within cohesionless parent flows was identified in the deposits of this relatively small-scale submarine landslide event.
    Beschreibung: Published
    Beschreibung: 1488-1504
    Beschreibung: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Flow transitions ; island volcano ; subaqueous cohesionless density flows ; submarine landslide deposits ; 04. Solid Earth::04.04. Geology::04.04.04. Marine geology ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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