海底地震仪广角地震试验

A WIDE ANGLE OCEAN BOTTOM SEISMIC SURVEY

介绍了海底地震仪(OBS)的基本原理、结构和海上调查方法,针对解决东海冲绳海槽地壳结构及性质等目的,利用大容量气枪枪阵震源和海底地震仪在东海冲绳海槽首次开展人工地震深部地球物理探测试验。本次试验布设一条NNW—SSE向垂直构造走向的勘测线,共投放海底地震仪40台,回收成功36台。获得了有效的深部地震数据,可识别到Pg、PmP、Pn等多种震相。此次试验是我国在冲绳海槽深部探测中的成功示范,有效填补了该地区深部地震数据的空白,为解决冲绳海槽深部地质问题奠定了坚实的基础。

An ocean bottom seismic survey(OBS)was carried out in the Okinawa Trough of the East China Sea for the purpose to reveal the structure and properties of the crust.Basic principles,structures and survey methods of OBS were briefly introduced in the paper.This is the first deep geophysical exploration ever carried out in the trough using the large capacity air-gun array as seismic source.A survey line was put on the bottom along the direction of NNW-SSE,perpendicular to the structural direction.A total of forty seismometers were placed,of which thirty six were reclaimed successfully.Deep seismic data has efficiently obtained in the test including the multiple seismic phases of Pg,PmP and Pn.It is indeed a successful demonstration of deep exploration for the first time in the Okinawa Trough of East China Sea,which effectively filled the gaps in the deep seismic survey and laid a solid foundation for solving deep geological problems in the region.