関東・東海地域の地震活動と地殻構造
1987 年 96 巻 4 号 p. 209-222
詳細
1987 年 96 巻 4 号 p. 209-222
The occurrence of large earthquakes in the Kanto-Tokai (K-T) district has been interpreted by the interaction among the Philippine Sea (PHS), the Eurasian (EUR) and the Pacific (PAC) Plates the PHS and PAC plates underthrust beneath the EUR plate in this region. In order to understand the tectonic process taking place beneath the K-T region, the seismic activity, velocity structure and source mechanisms were studied by using the data from recently developed seismological observation networks. The double-planed structure of the intermediate-depth seismic zone was observed clearly beneath the Kanto districts, and the PHS plate underthrusting from the Sagami and Suruga troughs were clearly delineated by the high velocity and high seismic region. The distribution of pressure axes corroborated the results derived from the hypocentral distribution.
