Accurate relocation of earthquakes in central-western China using the double-difference earthquake location algorithm

查看全文 作　　者：YANG Zhixian (杨智娴) CHEN Yuntai (陈运泰) ZHENG Yuejun (郑月军) Yü Xiangwei (于湘伟)[1] 机构地区：[1]Institute of Geophysics, China Seismological Bureau, Beijing 100081, China Institute of Geophysics, China Seismological Bureau, Beijing 100081, China Institute of Crustal Dynamics, China Seismological Bureau, Beijing 100085, China Institute of Geophysics, China Seismological Bureau, Beijing 100081, China 出　　处：《Science China Earth Sciences》索引2003年第46卷第z2期,共15页 摘　　要：The double-difference earthquake relocation algorithm (DD algorithm) has been applied to the accurate relocation of 10057 earthquakes in the central-western China (21°-36°N, 98°-112E°) during the period of 1992-1999. In total, 79706 readings for P waves and 72169 readings for S waves were used in the relocation, and the source parameters of 6496 events were obtained. The relocation results revealed a more complete picture of the hypocentral distribution in the central-western China. In several seismic belts the relocated epicenters present a more defined lineation feature, reflecting the close correlation between the seismicity and the active tectonic structures. The relocated focal depths confirmed that most earthquakes (91 percent of the 6496 relocated events) in the central-western China were located at shallower depths not deeper than 20 km. The distribution of focal depths indicates that the seismogenic layer in the central-western China is located in the upper-mid crust with its thickness no deeper than 20 km. 关 键 词：double-difference EARTHQUAKE location, central-western China, EARTHQUAKE relocation, SEISMOGENIC layer.