南天山地区巴楚-伽师地震(M_S6.8)发震构造初步研究  

THE PRELIMINARY STUDY ON SEISMOTECTONICS OF THE 2003 AD BACHU-JIASHI EARTHQUAKE (M_S 6.8), SOUTHERN TIAN SHAN

作　　者：徐锡伟[1] 张先康[2] 冉勇康[1] 崔效锋[3] 马文涛[1] 沈军[4] 杨晓平[1] 韩竹军[1] 宋方敏[1] 张兰凤[1] 

机构地区：[1]中国地震局地质研究所,北京100029 [2]中国地震局地球物理勘探中心,郑州450003 [3]中国地震局地壳应力研究所,北京100085 [4]新疆维吾尔自治区地震局,乌鲁木齐830011

出　　处：《地震地质》2006年第2期161-178,共18页Seismology and Geology

基　　金：中国地震局"新疆巴楚-伽师6.8级地震应急工作专项计划"项目资助。

摘　　要：新生代期间强烈而持久的再生造山作用,在天山地区形成了大量近EW向逆断裂-褶皱带,引起地壳强烈缩短,穿插有NW向“类转换断层”,显示出天山地区近NS向不均匀的构造挤压作用;区域上地震构造主要为近EW向逆断裂-褶皱带或盲逆断层,其次为NW向“类转换断层”。巴楚-伽师地震区位于南天山柯坪塔格推覆构造系以南,NE向跨越极震区、长约50km的深地震反射探测表明,1997年伽师强震群的发震构造推测为NW向隐伏“类转换断层”,2003年巴楚-伽师地震(MS6·8)的发震构造为柯坪塔格推覆构造系南缘尚未出露地表的近EW向盲逆断层系。Owing to strong and permanent Cenozoic re-orogenic processing, a lot of EW-striking active thrusts and folds have been developed in Tian Shan, resulting in crustal shortening in NS direction. There also exist NW-striking transform-like strike-slip faults that cut the Tian Shah and accommodate uneven crustal shortening larger in the west and smaller in the east. The seismogenic structures in and around the Tian Shan mainly include EW-striking thrust ramps or blind thrusts and NW-striking trans- form-like strike-slip faults. The 2003 AD Bachu-Jiashi earthquake is located at south of the Kalpintag nappe. A NE-trending deep seismic reflection profile about 50km long across the epicenter has been conducted after the earthquake. From this reflection profile four blind faults are identified. Together with earthquake relocation, these identified blind faults are used in the paper to interpret the seis- mogenic structures of the 1997 AD Jiashi strong earthquake swarm and 2003 AD Bachu-Jiashi earthquake. The 1997 AD Jiashi strong earthquakes were generated mainly by a NW-striking buried transform-like strike-slip fault, while the 2003 AD Bachu-jiashi earthquake by blind thrusts in front of the Kalpintag nappe.

关 键 词：巴楚-伽师地震 深地震反射探测 发震构造 天山 

分 类 号：P315.2[天文地球—地震学]