Geophysical processes and biosphere: article

Аnnotation: We have been considering characteristics of short-period S -wave attenuation field in the lithosphere of South-Western Japan. Recordings of local shallow earthquakes, obtained by station MAJO at distances of ~250-900 km were processed. We used method based on an analysis of a ratio of maximum amplitudes of Sn- and Pn -waves ( Sn / Pn parameter). The dependence of this parameter on distance was created. We compared this dependence with analogic dependences, obtained earlier in the region of North-Eastern Japan and also in the rupture zone of the great Maule earthquake (Central Chile, 27.02.2010, Mw = 8.8). The reasons of essential differences of these dependences in various regions are discussed. A correlation of Sn / Pn parameter values, recorded near rupture zones of large earthquakes of South-Western Japan ( Mw ≥ 7.0), with time passing after corresponding events is considered. A special attention is paid to apportionment of high attenuation zones in the areas where large earthquakes, occurred since 1900 are not known. By analogy with earlier obtained data it is supposed that preparation for large seismic event can realize in one of such zones.