文章摘要

文章信息/Info

作者:: 莘海亮¹; 刘明军¹; 张元生²; 曾宪伟³; 胡中民¹; (1.中国地震局地球物理勘探中心,郑州 450002; 2.中国地震局兰州地震研究所,兰州 730000; 3.宁夏回族自治区地震局,银川 750001)

Author(s):: XIN Hai-liang¹; LIU Ming-jun¹; ZHANG Yuan-sheng²; ZENG Xian-wei³; HU Zhong-min¹; (1.Research Center of Exploration Geophysics,China Earthquake Administration,Zhengzhou 450002,Henan,China)(2.Lanzhou Institute of Seismology,China Earthquake Administration,Lanzhou 730000,Gansu,China)(3.Earthquake Administration of Ningxia Hui Autonomous Region,Yinchuan 750001,Ningxia,China)

Keywords:: double-difference algorithm; genetic algorithm; focal depth; seismogenic layer; southeast area of Gansu

摘要:: 将双差地震定位法与遗传算法相结合,对2001～2007年甘东南地区的地震进行了重新定位。结果显示:重新定位后地震在空间分布上更加集中,部分地区的地震有向构造带趋近的变化。地震震源平均深度为14.6 km,5～20 km深度为该区多震层深度范围。3次5级以上中强地震的震中均处于主干活动断裂边缘。震源深度分布与断裂构造的关系刻画出剖面沿线不同断裂的深部展布特征,部分断裂延伸到中、下地壳。

Abstract:: We relocate earthquakes occurred in the southeast area of Gansu from 2001 to 2007 using double-difference method and genetic algorithm method.The result shows that the earthquakes are more spatially concentrated and in some areas the earthquakes tend to get close to tectonic belts.The average hypocenter depth is 14.6 km and the seismogenic layer ranges from 5 km to 20 km.After relocating three moderately strong earthquakes,we find that they were all occurred in the edge of the main active faults.The relationship between seismic depth distribution and fault structure portray the spreading characteristics of different faults along the profile in the deep,and some faults stretch to the middle and deep crust.