摘要
2003年2月24日发生在新疆塔里木盆地的巴楚-伽师6.8级地震可能是1997—1998年伽师强震群的继续,但其震源机制解、破裂过程与1997—1998年的强震群有一定的差别。从地震重新定位的结果看,巴楚-伽师6.8级地震与塔西南坳陷东侧麦盖提斜坡带上发育的一组NWW向隐伏逆断层有关,地震宏观考察①所发现的与构造变形有关的地裂缝也与这一隐伏断层带的位置相吻合,等震线形态与隐伏断层带的走向一致,极震区的形态与断层的破裂方向基本一致。这些均表明这次地震是盆地内一条近EW向北倾逆断层自NW向SE由深至浅破裂的结果。
The Ms 6.8 Bachu-Jiashi earthquake of Feb. 24, 2003 occurred in the western Tarim Basin and is possibly the continuation of the Jiashi strong earthquake swarms in 1997-1998. However, its focal mechanism and rupture process are different from that of the Jiashi strong earthquake swarms, according to our preliminary study on its seismic tectonics with geomorphologic information from satellite images, the deep structures from the petroleum seismic exploration, the macro damage and isoseismic features from field investigation, the relocation of the epicenters of the aftershocks, and the regional seismic tectonics from both deep and surface tectonics. The occurrence of the Ms 6.8 Bachu-Jiashi earthquake is closely related with the revealed reverse fault on the Maigaiti slope belt between the Bachu uplift and Kashi depression in western Tarim Basin. The sites of the ground fissures found in the field fit with the revealed reverse fault. Isoseismal features are also corresponding to the rupture direction of the fault. These evidences indicate that the Ms 6.8 Bachu-Jiashi earthquake is the result of the southward rupturing from deep to shallow along a north-dipping reverse fault in Tarim Basin. This reverse fault is possibly the result of the propagation of the thrust fault-fold system named Kalpintag thrust belt in the front of Tianshan.
出处
《地震地质》
EI
CSCD
北大核心
2006年第2期205-212,共8页
Seismology and Geology
基金
新疆科技攻关项目(200333116)
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
科技部国际合作重点项目(2004DFBA0005)资助
关键词
巴楚-伽师地震
发震构造
塔里木盆地
Bachu-Jiashi earthquake, seismogenic tectonics, Tarim Basin
作者简介
沈军，男，1966年生，1987年毕业于北京大学地质系，1998年在中国地震局地质所获得地质学博士学位，2001年在中国科学院地质与地球物理研究所结束博士后研究工作，研究员，主要从事现今地壳运动与动力学、地震安全性评价、城市活断层探测与地震危险性预测研究。电话：0991—3835881，E—mail：shenjuneq@263．net。
