INGV Rome

Rome, Italy

INGV Rome

Rome, Italy
SEARCH FILTERS
Time filter
Source Type

Boncio P.,University of Chieti Pescara | Amoroso S.,University of L'Aquila | Vessia G.,University of Chieti Pescara | Vessia G.,CNR Research Institute for Geo-hydrological Protection | And 9 more authors.
Bulletin of Earthquake Engineering | Year: 2017

In this study, we analyse the susceptibility to liquefaction of the Pozzone site, which is located on the northern side of the Fucino lacustrine basin in central Italy. In 1915, this region was struck by a M 7.0 earthquake, which produced widespread coseismic surface effects that were interpreted to be liquefaction-related. However, the interpretation of these phenomena at the Pozzone site is not straightforward. Furthermore, the site is characterized by an abundance of fine-grained sediments, which are not typically found in liquefiable soils. Therefore, in this study, we perform a number of detailed stratigraphic and geotechnical investigations (including continuous-coring borehole, CPTu, SDMT, SPT, and geotechnical laboratory tests) to better interpret these 1915 phenomena and to evaluate the liquefaction potential of a lacustrine environment dominated by fine-grained sedimentation. The upper 18.5 m of the stratigraphic succession comprises fine-grained sediments, including four strata of coarser sediments formed by interbedded layers of sand, silty sand and sandy silt. These strata, which are interpreted to represent the frontal lobes of an alluvial fan system within a lacustrine succession, are highly susceptible to liquefaction. We also find evidence of paleo-liquefaction, dated between 12.1–10.8 and 9.43–9.13 kyrs ago, occurring at depths of 2.1–2.3 m. These data, along with the aforementioned geotechnical analyses, indicate that this site would indeed be liquefiable in a 1915-like earthquake. Although we found a broad agreement among CPTu, DMT and shear wave velocity “simplified procedures” in detecting the liquefaction potential of the Pozzone soil, our results suggest that the use and comparison of different in situ techniques are highly recommended for reliable estimates of the cyclic liquefaction resistance in lacustrine sites characterized by high content of fine-grained soils. In geologic environments similar to the one analysed in this work, where it is difficult to detect liquefiable layers, one can identify sites that are susceptible to liquefaction only by using detailed stratigraphic reconstructions, in situ characterization, and laboratory analyses. This has implications for basic (Level 1) seismic microzonation mapping, which typically relies on the use of empirical evaluations based on geologic maps and pre-existing sub-surface data (i.e., age and type of deposits, prevailing grain size, with particular attention paid to clean sands, and depth of the water table). © 2017 Springer Science+Business Media B.V.


Simonelli A.,University of Pisa | Belfi J.,National Institute of Nuclear Physics, Italy | Beverini N.,University of Pisa | Carelli G.,University of Pisa | And 5 more authors.
Near Surface Geoscience 2015 - 21st European Meeting of Environmental and Engineering Geophysics | Year: 2015

In recent years the development of large ring laser gyroscopes gave birth to a new discipline: the rotational seismology. This field of study is rapidly expanding and many areas of geophysics are or can be involved, from geodesy to seismology to the monitoring of critical structures. New rotational sensors based on optical interferometry and Sagnac effect has been developed in the last two decades. These sensors are called ring laser gyroscopes (RLG) and are now able to cover the range of rotations of seismological interest i.e. from 10-2 to 10-9 rad/sec. A measure of rotations in seismology is of fundamental interest for several reasons: Quantitative seismology requires a measure of all the six degrees of freedom that characterize a rigid body's motion. Standard seismological observations are contaminated by rotations that produce a bias in the estimate of ground translation. Rotational observables provide important informations about the elastic properties of the subsoil. The extension of rotational observations to exploration seismology can improve resolution and accuracy of subsurface imaging. © (2015) by the European Association of Geoscientists & Engineers (EAGE).


Berlusconi A.,University of Insubria | Brunori C.A.,INGV Rome | Campagnoli P.,AMBIENTE TERRA Studio Associato | Cinti F.R.,INGV Rome | And 9 more authors.
Rendiconti Online Societa Geologica Italiana | Year: 2013

In order to geometrically characterize the liquefaction features observed in the epicentral sector of the 2012 Emilia seismic sequence and to evaluate the potential for recording palaeoseismic features of the area, we performed two electric resistivity tomographic sections and 4 shallow corings, coupled with 14C datings and archaeological age estimates in selected sites. Preliminary results show that there is a good agreement between ERT sections and core-logs; moreover a major role in determining the scalar relationships of the liquefaction features is played by the local geomorphological and topographic setting. The high sedimentation rates obtained through core datings (4 - 20 mm/yr) suggest that the described methodological approach can cover time windows of only a few centuries, thus hardly encompassing, in this tectonic setting, a significant period for paleoseismological purposes. © Società Geologica Italiana, Roma 2013.


Martorana R.,University of Palermo | Capizzi P.,University of Palermo | D'Alessandro A.,INGV Rome | Luzio D.,University of Palermo
Near Surface Geoscience 2015 - 21st European Meeting of Environmental and Engineering Geophysics | Year: 2015

A systematic comparison is presented between some 2D resistivity models and their images by the inversion of synthetic datasets relating to three different arrays, suitable for multichannel data acquisitions (dipole-dipole (DD), Wenner-Schlumberger (WS) and multiple gradient (MG)). The goal is to study how the measurement errors affects the resolution of the tomographic models and the ability to retrieve correct information on buried targets. We considered different data acquisition patterns, gradually increasing the complexity of the combinations of potential spacing and dipolar distance. To this end we increased the number of current dipoles to obtain approximately the same amount of measures, increasing the investigation time. Results from noise-free and noisy data are discussed and compared with those from field data. The results show that: the quality of the inversion models, for a fixed noise level, depends significantly on the data acquisition pattern; the information recovery and the resolution, being equal the number of measurements, is overall better for WS and worse for DD; the decrease of sensitivity with depth is lower for particular acquisition patterns that allow to better resolve deeper targets; the MG array can be preferred because it provides comparable results, using a smaller number of current electrodes. © (2015) by the European Association of Geoscientists & Engineers (EAGE).


PubMed | INGV Rome
Type: Journal Article | Journal: Geophysical research letters | Year: 2015

Space-time clustering is the most striking departure of large earthquakes occurrence process from randomness. These clusters are usually described ex-post by a physics-based model in which earthquakes are triggered by Coulomb stress changes induced by other surrounding earthquakes. Notwithstanding the popularity of this kind of modeling, its ex-ante skill in terms of earthquake predictability gain is still unknown. Here we show that even in synthetic systems that are rooted on the physics of fault interaction using the Coulomb stress changes, such a kind of modeling often does not increase significantly earthquake predictability. Earthquake predictability of a fault may increase only when the Coulomb stress change induced by a nearby earthquake is much larger than the stress changes caused by earthquakes on other faults and by the intrinsic variability of the earthquake occurrence process.

Loading INGV Rome collaborators
Loading INGV Rome collaborators