In accordance with the principle of similarity in geology and topography, the Vs^30 （the average shear-velocity down to a 30m depth below the surface） approximation of sites is acquired by correlation between Vs^30 ...In accordance with the principle of similarity in geology and topography, the Vs^30 （the average shear-velocity down to a 30m depth below the surface） approximation of sites is acquired by correlation between Vs^30 and slopes after calculating the maximum slope of topography using the 30-sec Chinese Mainland DEM （Digital Elevation Model） data set. Site-amplification factors are then quantified with Vs^30 and applied to the ShakeMap system developed by this study to revise ground-motion amplitudes on bedrock estimated from empirical relationships. Finally, the distribution of ground motion parameters on the surface is obtained. This article also introduces the calculation process, calculation models of the ShakeMap systems and related software systems. In conclusion, certain examples indicate that the ShakeMap system is feasible in the Chinese Mainland.展开更多
The investigated area is located in the western Ionian Sea, which is an area widely occupied by the external from of the Calabrian Arc. It is characterized by a very rough morphology of the seafloor mainly induced by ...The investigated area is located in the western Ionian Sea, which is an area widely occupied by the external from of the Calabrian Arc. It is characterized by a very rough morphology of the seafloor mainly induced by the thrusting and back-thrusting activity. Such a tectonic regime is extremely favourable for the presence of gas and related fluid migration. New processed line MS-24 and swath-bathymetric data highlighted the presence of positive structures at the seafloor interpreted as mud volcanoes. Along the seismic profile we have also recognized a high amplitude reflector that, although it corresponds to a stratigraphic horizon, it shows an anomalous high amplitude character. The seismic velocity field shows evidences of free gas occurrence and so it cannot be excluded the hypothesis that the high amplitude reflector could be a ＂bottom simulating reflector-BSR＂.展开更多
基金sponsored by the Basic Scientific Research Business Special,Institute of Geophysics,China Earthquake Administration (BQJB08B24)
文摘In accordance with the principle of similarity in geology and topography, the Vs^30 （the average shear-velocity down to a 30m depth below the surface） approximation of sites is acquired by correlation between Vs^30 and slopes after calculating the maximum slope of topography using the 30-sec Chinese Mainland DEM （Digital Elevation Model） data set. Site-amplification factors are then quantified with Vs^30 and applied to the ShakeMap system developed by this study to revise ground-motion amplitudes on bedrock estimated from empirical relationships. Finally, the distribution of ground motion parameters on the surface is obtained. This article also introduces the calculation process, calculation models of the ShakeMap systems and related software systems. In conclusion, certain examples indicate that the ShakeMap system is feasible in the Chinese Mainland.
文摘The investigated area is located in the western Ionian Sea, which is an area widely occupied by the external from of the Calabrian Arc. It is characterized by a very rough morphology of the seafloor mainly induced by the thrusting and back-thrusting activity. Such a tectonic regime is extremely favourable for the presence of gas and related fluid migration. New processed line MS-24 and swath-bathymetric data highlighted the presence of positive structures at the seafloor interpreted as mud volcanoes. Along the seismic profile we have also recognized a high amplitude reflector that, although it corresponds to a stratigraphic horizon, it shows an anomalous high amplitude character. The seismic velocity field shows evidences of free gas occurrence and so it cannot be excluded the hypothesis that the high amplitude reflector could be a ＂bottom simulating reflector-BSR＂.
