摘要
2022年1月23日、3月26日和4月15日青海省德令哈市分别发生M_(S)5.8、M_(S)6.0和M_(S)5.4地震。采用CAP方法反演了M_(S)6.0地震及6次M_(S)≥3.7地震的震源机制解和震源矩心深度,利用双差定位方法重新定位了德令哈M_(S)6.0地震序列的震源位置,初步分析了德令哈M_(S)6.0地震序列的发震背景。震源机制结果显示,M_(S)6.0地震震源机制解节面Ⅰ:走向174°/倾角80°/滑动角-156°,节面Ⅱ:走向79°/倾角66°/滑动角-11°,矩心深度6 km。地震重定位结果显示,德令哈M_(S)6.0地震序列震中呈NS向展布、震源区北部为主体破裂区域。基于震源机制解、地震重定位结果和震源区附近局部发育NS向构造的特征,分析认为德令哈M_(S)6.0地震序列的发震构造为一条NS向、高倾角的右旋走滑隐伏断层。
A 5.8-magnitude,a 6.0-magnitude,and a 5.4-magnitude earthquake occurred respectively on Jan.23,Mar.26 and Apr.15,2022 in Delingha city of Qinghai province.We firstly inverted the focal mechanisms and the centroid depth of the source of the M_(S)6.0 main shock and other 6 M_(S)≥3.7 aftershocks by the CAP method,then we relocated the sources of the M_(S)6.0 earthquake sequence by the hypoDD method,and analyzed the characteristics of the focal mechanisms,the relocated source parameters and the seismogenic structure.The focal mechanism of the Delingha M_(S)6.0 earthquake has 2 solutions:for the first nodal plane,strike is 174°,dip is 80°,rake is-156°.For the second nodal plane,strike is 79°,dip is 66°,rake is-11°.The centroid depth is 6 km.The sources of the M_(S)6.0 earthquake sequence are mainly distributed in North-South direction.According to the focal mechanism,relocated source parameters,and the geological structure in the source region,the seismogenic structure of the M_(S)6.0 earthquake sequence is a hidden fault with high dip angel in North-South direction.
作者
黄浩
袁伏全
李丽
赵燕杰
万玉杰
马建新
李启雷
胡维云
郭瑛霞
HUANG Hao;YUAN Fuquan;LI Li;ZHAO Yanjie;WAN Yujie;MA Jianxin;LI Qilei;HU Weiyun;GUO Yingxia(Qinghai Earthquake Agency,Xining 810017,Qinghai,China;Shanxi Earthquake Agency,Taiyuan 030021,Shanxi,China)
出处
《地震研究》
CSCD
北大核心
2023年第4期473-482,共10页
Journal of Seismological Research
基金
中国地震局地震科技星火计划(XH21036Y)
山西省应用基础研究计划面上青年基金项目(201901D211549)
青海省地震科学基金(2021A02,2022C01).
关键词
德令哈地震
地震重定位
震源机制
发震背景
青海
the Delingha earthquake
earthquake relocation
focal mechanism
seismic tectonic background
Qinghai
