南冲绳海槽海域微震活动的初步探讨

PRELIMINARY STUDY OF THE MICROSEISMICITY IN THE SOUTHERN OKINAWA TROUGH

通过解析在南冲绳海槽海域投放的海底地震仪（ＯＢＳ）记录到的天然地震资料，得到近垂直海槽走向的微震震中分布．根据震中分布与海底地形、地质构造的对比，提出：南冲绳海槽海域的微震活动频繁且多数集中于海槽轴部的地堑和琉球岛弧中部．

Using the microseismic data recorded by the OBS. deployed in the southern Okinawa Trough, the epicentral distribution of microearthquakes along the direction perpendicular to the general strike of the local tectonics is acquired. By comparing the epicenters with the topography and tectonics, it is found that most of the frequent microearthquakes are concentrated on the grabens and the axis of the Ryukyu Arc.