关键词: 地震台阵, 震源联合定位, 新疆伽师

Abstract: In 1997, 7 strong earthquakes ( M >6.0) occurred in Jiashi region, Xinjiang Uygur Autonomous Region. In order to gain an insight into this seldom seen seismic event, a passive broadband seismic array experiment was carried out by the Institute of Geology, China seismological Bureau in 1998. During the experiment two events, the Binamu and Lonkou earthquakes ( M ≥6.0), and their aftershock sequences were recorded by the portable seismic array. In this paper, these two earthquake sequences are relocated by using the Geiger method and the Joint Hypocenter Determination (JHD) method, respectively. The results show that: 1) the JHD method can be used to locate the relative position of an aftershock sequence more precisely than the Geiger method; 2) the Binamu and Longkou aftershock sequences delineate two nonparallel SWW trending faults, the occurrence of which are roughly consistent with those given by the moment tensor solution of the corresponding main shocks, and hence can be used for determining the focal plane of the Jiashi events; 3) the Binamu and Longkou earthquakes occurred at the gradient zone of the crust mantle boundary and at the convergence of the crustal high and low velocity media nearby the deep faults; this may indicate that the genesis of these earthquakes bears a close relation to the deep geological environment within the crust; 4) the tensional rupturing feature of the Jiashi earthquake sequence might be resulted from the heterogeneous lateral deformation of the northern edge of the Tarim basin.

Key words: Seismic Array, Joint Hypocenter Determination (JHD), Earthquake location, Jiashi