THE RELOCATION AND SEISMOGENIC STRUCTURE OF THE DELINGHA EARTHQUAKE SEQUENCE OF 2003 IN QINGHAI
SUN Chang-hong1, QIAN Rong-yi1, XIAO Guo-lin2, MENG Xiao-hong1
1. Geo-detection Laboratory, Ministry of Education, China University of Geoscience, Beijing 100083, China;
2. School of Energy Resources, China University of Geoscience, Beijing 100083, China
The authors made initial location of the main shock of ML= 6.7 and aftershocks of totally 117 events with magnitude ML>1.0 for Delingha earthquake sequence till October 25, 2003, using the location intersection technique, and relocated 117 events using Double Difference Algorithm. It is known that the epicenter of the main shock was 37.566°N and 96.509°E, and the focal depth of the main shock was 13 km. The distribution of the aftershocks epicenters was consistent with the fault plane of 294° obtained from the focal mechanism of Harvard. The relocation results for the Delingha earthquake sequence clearly indicate that the seismogenic structure of the Delingha earthquake sequence is the NWW-SEE striking and NE-dipping Da Qaidam-Zongwulong Mountain modern active fault belt through the focal region. It is also indicated that the maximum horizontal main stress in this regional stress field is in the direction of about N24°E to N34°E .
孙长虹, 钱荣毅, 肖国林, 孟小红. 2003年青海德令哈地震序列的重新定位和发震构造[J]. 物探与化探, 2006, 30(1): 79-82.
SUN Chang-hong, QIAN Rong-yi, XIAO Guo-lin, MENG Xiao-hong. THE RELOCATION AND SEISMOGENIC STRUCTURE OF THE DELINGHA EARTHQUAKE SEQUENCE OF 2003 IN QINGHAI. Geophysical and Geochemical Exploration, 2006, 30(1): 79-82.
[1] 谢富仁,崔效锋,张景发,等.中国现代构造应力场基本特征分区.中国大陆地壳应力环境研究.北京:地震出版社,2003:39.
[2] 谢富仁,崔效锋,张景发,等.中国大陆现代构造应力场与强震活动关系.中国大陆地壳应力环境研究.北京:地震出版社,2003:69.
[3] Waldhause F,Ellsworth W L.A double difference earthquake location algorithm:Method and application to the Northern Hayward Fault,California[J].Bull Seism Soc Amer,2000,90(6):1353.
[4] 杨智娴,陈运泰,郑月军,等.双差地震定位法在我国中西部地区地震精确定位中的应用[J].中国科学,2003,33(增刊):129.
[5] 王有学,Mooney W D,韩果花,等.台湾—阿尔泰地学断面阿尔金—龙门山剖面的地壳纵波速度结构[J]. 地球物理学报,2005,48(1):98.
[6] Paige C C,Saunders M A.LSQR: Sparse linear equations and least squares problems.ACM Transactions on Mathematical Software.8/2,1982:195.
[7] 青海省地质矿产局.中华人民共和国地质矿产部 地质专报—区域地质(第24号):青海省区域地质志[M].北京:地质出版社,1991:538.
[8] 曾秋生.青海地震综合研究[M].北京:地震出版社,1999:90.
[9] 候遵泽,杨文采.中国重力异常的小波变换与多尺度分析[J].地球物理学报,1997,40(1):85.