文章摘要

文章信息/Info

Title:: Accurate Location of the 2003 Minle-Shandan M6.1,5.8 Earthquake Sequence

作者:: 莘海亮¹; 张元生¹; 2; 郭晓¹; 2; 李稳¹; (1.中国地震局兰州地震研究所,兰州 730000; 2.中国地震局地震预测研究所兰州科技创新基地,兰州 730000)

Author(s):: XIN Hai-liang¹; ZHANG Yuan-sheng¹; 2; GUO Xiao¹; 2; LI Wen¹; (1.Lanzhou Institute of Seismology,CEA,Lanzhou 730000,Gansu,China)(2.Lanzhou Base of Institute of Earthquake Science,CEA,Lanzhou 730000,Gansu,China)

Keywords:: Minle-Shandan; accurate earthquake location; Genetic algorithm; seismogenic structure

摘要:: 利用遗传算法对2003年10月25日甘肃民乐—山丹6.1、5.8级地震及其余震进行了精确定位,并在此基础上结合地质资料讨论了此次地震的发震构造。定位结果表明:地震序列分布集中,两次主震主要沿着民乐—永昌隐伏断裂分布; 震源深度主要分布在10～15 km范围内,平均深度为12.1 km; 此次地震序列的发震构造为民乐—永昌隐伏断裂与童子坝河隐伏断裂所组成的大黄山隆起区前缘逆冲断裂,其中民乐—永昌隐伏断裂西段的NWW向局部断裂起主要作用。

Abstract:: Two earthquakes(M6.1,5.8)occurred in Minle-Shandan,Gansu,on Oct.25,2003.In order to obtain the accurate locations of the earthquake sequence,we used Genetic Algorithm to relocate it,and discussed its seismogenic structure combining with geologic data.The result shows that the sequence distributes centrally,and two mainshocks distribute along the Minle-Yongchang concealed fault.The focal depths range mainly from 10 km to 15 km,the average 12.1 km.The seismogenic structure is the thrust of the Dahuangshan frontal uplifts constituted by the Minle-Yongchang concealed fault and Tongzibahe concealed fault,and the west segment of the NNW-trending Minle-Yongchang concealed fault is main seismogenic structure.