26 research outputs found

    A multidisciplinary approach to the seismotectonics of the Lunigiana and Garfagnana extensional basins (Northern Tuscany, Italy)

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    New geological and morpho-structural surveys are integrated with seismological and seismic reflection data in order to define the active and potentially seismogenic sources of the Lunigiana and Garfagnana extensional basins (Tuscany, Northern Italy). The seismogenic role of the E-W-striking transfer fault between the Lunigiana and Garfagnana basins, located at the northern termination of the Apuane metamorphic core, and its possible association with a number of historical earthquakes are also discussed

    Imaging the three-dimensional architecture of the Middle Aterno basin (2009 L’ Aquila earthquake, Central Italy) using ground TDEM and seismic noise surveys: preliminary results

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    We present preliminary results from a multidisciplinary geophysical approach ap- plied to the imaging of the three-dimensional architecture of the Middle Aterno basin, close to the epicentral area of the 2009 L’Aquila earthquake (central Italy). We collected several time domain electromagnetic soundings (TDEM) coupled with seismic noise measurements focu- sing on the characterization of the bedrock/in ll interface. Our preliminary results agree with existing geophysical data collected in the area, and show that the southeastern portion of the basin is characterized by a deepening of the Mesozoic-Tertiary bedrock down to a depth of more than 450 m. We found that a joint use of electromagnetic and seismic methods signi - cantly contributes in obtaining new insights on the 3D geometry of the Middle Aterno basin. Moreover, we believe that our combined approach based on TDEM and noise measurements can be adopted to investigate similar geological settings elsewhere.PublishedPescina (AQ), Italy2T. Tettonica attiva3T. Pericolosità sismica e contributo alla definizione del rischio7A. Geofisica di esplorazioneope

    Imaging the three-dimensional architecture of the Middle Aterno basin (2009 L’Aquila earthquake, Central Italy) using ground TDEM and seismic noise surveys: preliminary results

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    We present preliminary results from a multidisciplinary geophysical approach applied to the imaging of the threedimensional architecture of the Middle Aterno basin, close to the epicentral area of the 2009 L’Aquila earthquake (central Italy). We collected several time domain electromagnetic soundings (TDEM) coupled with seismic noise measurements focusing on the characterization of the bedrock/infill interface. Our preliminary results agree with existing geophysical data collected in the area, and show that the southeastern portion of the basin is characterized by a deepening of the Mesozoic-Tertiary bedrock down to a depth of more than 450 m. We found that a joint use of electromagnetic and seismic methods significantly contributes in obtaining new insights on the 3D geometry of the Middle Aterno basin. Moreover, we believe that our combined approach based on TDEM and noise measurements can be adopted to investigate similar geological settings elsewhere.PublishedPescina (AQ)2T. Tettonica attivaope

    A database of the coseismic effects following the 30 October 2016 Norcia earthquake in Central Italy

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    We provide a database of the coseismic geological surface effects following the Mw 6.5 Norcia earthquake that hit central Italy on 30 October 2016. This was one of the strongest seismic events to occur in Europe in the past thirty years, causing complex surface ruptures over an area of >400 km 2. The database originated from the collaboration of several European teams (Open EMERGEO Working Group; about 130 researchers) coordinated by the Istituto Nazionale di Geofisica e Vulcanologia. The observations were collected by performing detailed field surveys in the epicentral region in order to describe the geometry and kinematics of surface faulting, and subsequently of landslides and other secondary coseismic effects. The resulting database consists of homogeneous georeferenced records identifying 7323 observation points, each of which contains 18 numeric and string fields of relevant information. This database will impact future earthquake studies focused on modelling of the seismic processes in active extensional settings, updating probabilistic estimates of slip distribution, and assessing the hazard of surface faulting

    H/V dal rumore sismico ambientale: Tool efficace per lo studio delle cavità?

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    Si presentano casi studio utilizzando il metodo H/V per lo studio di cavità naturali o antropiche. Misure di rumore sismico sono state effettuate in diversi siti, acquisendo dati contemporaneamente all'interno e sopra cavità. Lo scopo del presente lavoro è capire sperimentalmente se con misure di rumore sismico in superficie è possibile avere indicazioni sulla presenza di cavità sepolte. Sebbene le curve H/V calcolate al di sopra delle cavità abbiano spesso mostrato ampiezze minori di 1 nel range delle alte frequenze (> 20 Hz), i risultati sperimentali non sembrano univoci e ulteriori studi sia numerici che sperimentali sono necessariPublishedL'Aquila3T. Pericolosità sismica e contributo alla definizione del rischiorestricte

    Morphotectonic analysis of the Lunigiana and Garfagnana grabens (northern Apennines, Italy): Implications for active normal faulting

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    This work integrates existing structural geology data with new detailed geomorphic analyses of the fluvial network to characterize active and potentially seismogenic faults bordering the Lunigiana and Garfagnana basins in the northern Apennines of Italy. These two basins are NW–SE-oriented asymmetric grabens, bordered by several normal faults with a poorly known, but probable recent slip history. Several strong earthquakes (M 5.0–6.5) have occurred in the area in the last millennium, demonstrating that this is one of the most seismically active areas of the northern Apennines. However, the lack of reliable instrumental data for strong earthquakes, generally low deformation rates, and poor exposures of faulted Quaternary sediments render the characterization of active, seismogenic faults problematic. Here, we quantify the relationships between faults and watershed-scale geomorphology using 10-m digital topography to extract channel and basin metrics, such as steepness, concavity, and stream length-gradient indices of modeled river longitudinal profiles. In particular, convex segments of longitudinal profiles (knickpoints) are investigated in the spatial context of suspected active faults. Several knickpoints arise locally from juxtaposed rock types of different erodibility; however, many others mapped along major normal faults have a clear tectonic origin. In fact, the height of the footwall knickpoints (the closest to the fault trace) varies along-strike the fault, increasing toward the fault center and tapering off toward the fault tips, mimicking the expected displacement profile of a fault. In these cases, we consider the knickpoint height as a proxy of the fault throw accumulated by the youngest fault activity, probably during the late Quaternary. The along-strike distribution of knickpoint heights helps in defining the likely segmentation pattern of the fault system. The identified active normal fault segments have lengths ranging from 9.5 to 28.5 km. The inferred late Quaternary throw rate ranges from 0.3 to 0.8 mm/a; however, the absence of any offset datable material limits our ability to assign precise numeric ages and rates of offset to the faulting
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