稠密地震観測による近畿地方北部の地震活動と地殻構造

Abstract

In the northern Kinki district, we have done seismic observations using the dense seismic array stations since 2008. Total 150 temporal and permanent stations are used, and the average interval between the stations is about 5km. Using these data, we have investigated the seismic velocity structure, the shape and distribution of the reflector in the lower crust, the Moho and the PHS plate, the focal mechanisms and the stress field etc. The results of these observations and other geophysical data exhibit and characterize the strong contrast between the Tamba region and the Oumi Basin region. Difference of these two region caused to the geometry of subducting PHS plate beneath this area and the distribution and the movement of fluid in the crust.