门源M_(s)6.9地震序列及祁连山地震带余震序列的统计特征研究  

Statistical characteristics of Menyuan M_(s)6.9 earthquake sequence and aftershock sequences in Qilian Mountain seismic zone

作　　者：张成军 严武建[2] 康林 ZHANG Chengjun;YAN Wujian;KANG Lin(Gansu Earthquake Agency,Lanzhou 730000,China;Key Laboratory of Loess Earthquake Engineering,China Earthquake Administration,Lanzhou 730000,China)

机构地区：[1]甘肃省地震局,甘肃兰州730000 [2]中国地震局黄土地震工程重点实验室,甘肃兰州730000

出　　处：《自然灾害学报》2023年第5期56-63,共8页Journal of Natural Disasters

基　　金：甘肃省地震局地震科技发展基金项目(2020Q10);中国地震局工程力学研究所基本科研业务费资助项目(2020EEEVL0304)。

摘　　要：基于2022年1月8日门源M_(s)6.9地震余震序列数据和祁连山地震带24次5.0级以上地震余震序列的统计分析,研究了门源M_(s)6.9地震震源机制与余震序列类型,以及祁连山地震带中强地震活动性、余震序列类型及分布规律、最大余震震级与主震关系及余震序列类型与主震断层性质之间的关系。研究结果表明:门源M_(s)6.9地震为主余型类型地震;该地震带5.0级以上中强地震存在3个丛集活动阶段且持续时间约为4 a,门源M_(s)6.9地震的发生意味着祁连山地震带进入了中强地震活跃阶段;以主余型余震序列类型为主,震群型和孤立型余震序列为辅,具有显著的分区特性,且主余型序列类型主震震级与1 a内最大余震震级之间具有高度相关性。祁连山地震带中强地震余震序列主震与主震断层类型以主震破裂滑动型为主,占比达到66.7%。Based on the aftershock sequence data of Menyuan M_(s)6.9 earthquake on January 8,2022 and the statistical analysis of 24 aftershock sequences of M_(s)5.0 earthquake or higher in Qilian Mountain seismic zone,the focal mechanism and aftershock sequence type of Menyuan M_(s)6.9 earthquake was investigated,as well as the seismic activity aftershock sequence type and distribution pattern of moderately strong earthquakes,the relationship between the maximum aftershock magnitude and the mainshock,and the relationship between the aftershock sequence type and the mainshock fault in Qilian Mountain seismic zone.The results show that Menyuan M_(s)6.9 earthquake is the main aftershock type.There are three clusters of moderate-to-strong earthquakes of M_(s)5.0 with a duration about 4 years,and the occurrence of Menyuan M_(s)6.9 earthquake means that the seismic zone of Qilian Mountain has entered the active stage of moderate-to-strong earthquakes.The main aftershock sequence type is the main aftershock type,supplemented by cluster and isolated aftershock sequences,which has significant zoning characteristics,and the main aftershock has a high correlation between the mainshock magnitude and the maximum aftershock magnitude within one year.The mainshock and mainshock fault types of moderate-to-strong earthquake aftershock sequences in the Qilian Mountain seismic zone are dominated by the mainshock rupture-slip type,accounting for 66.7%of the total.

关 键 词：门源6.9级地震 祁连山地震带 序列类型 最大余震震级 主震断层性质 

分 类 号：P315[天文地球—地震学]