青海门源地震震区视向地表形变特征与地震活动趋势  

Characteristics of apparent surface deformation and seismic activity trend of Menyuan earthquake in Qinghai

作　　者：熊文顺 任二峰[1] 夏楚林[1] XIONG Wenshun;REN Erfeng;XIA Chulin(College of Geological Engineering,Qinghai University,Xining 810016,China)

机构地区：[1]青海大学地质工程系,青海西宁810016

出　　处：《青海大学学报》2023年第2期106-112,共7页Journal of Qinghai University

基　　金：青海省科学技术厅项目(2020-ZJ-762)。

摘　　要：为确定2022年门源Ms6.9地震发生后第一周期内震区断层视向地表形变特征,预测震区地震活动趋势,本文在综合震区地质资料的基础上,利用D-InSAR技术获得门源Ms6.9地震发生后第一周期内视向地表形变图,确定了第一周期内震区断层视向形变特征。结果表明:门源地震发生后震区第一周期内托莱山断裂东段南侧视向地表形变最大形变量为1.5 cm。冷龙岭断裂南侧整体视向形变为抬升,形变最大值为1.8 cm,并具有沿冷龙岭断裂向东滑动的特征。冷龙岭断裂北侧自西向东地表形变表现为抬升,抬升的形变最大值为3.9 cm,这一抬升状态停止于Ms5.2和Ms4.5余震发生位置,地表形变转变为沉降,沉降的形变最大值为-1.8 cm,认为是由于冷龙岭断裂北侧先发生了视向的沉降变形后对滑动前进方向视向抬升变形区域进行挤压,促使其再次产生视向地表抬升形变。综合第一周期内地表形变特征、长时间余震分布情况和冷龙岭断裂运动方向认为,在冷龙岭断裂北侧、肃南—祁连断裂南侧及冷龙岭断裂东部金强河—毛毛山—老虎山断裂等未来发生地震的危险性增加。In order to determine the characteristics of apparent surface deformation of the fault in the seismic area in the first period after Menyuan Ms6.9 earthquake in 2022,and predict the seismic activity trend in the area,on the basis of comprehensive geological data of seismic area,D-InSAR is used to obtain the visual surface deformation map in the first period after the earthquake,so as to determine the characteristics of apparent surface deformation of the fault in the seismic area in the first period.The results show that the maximum apparent surface deformation on the southern side of the eastern section of Tuolaishan fault in the first cycle after Menyuan earthquake is 1.5cm.The overall apparent deformation on the south side of Lenglongling fault is uplift with the maximum deformation value of 1.8 cm,and it is characterized by eastward sliding along the fault.The surface deformation on the north side of Lenglongling fault from west to east is uplift with the maximum deformation value of 3.9 cm.The uplift stops at the location where Ms5.2 and Ms4.5 aftershocks occur,and the surface deformation changes to subsidence with the maximum deformation value of-1.8 cm.It is believed that apparent subsidence deformation occurrs first on the north side of Lenglongling fault,and then the apparent uplift deformation area in the sliding direction is extruded,which causes the apparent uplift deformation to occur again.It is concluded that the risk of earthquakes on the north side of Lenglongling fault,the south side of Sunan-Qilian fault and Jinqianghe-Maomaoshan-Laohushan fault in the east of Lenglongling fault will increase based on the characteristics of surface deformation in the first cycle,the distribution of long-term aftershocks and the movement direction of Lenglongling fault.

关 键 词：门源地震 D-INSAR技术 地表形变 余震活动 

分 类 号：P315[天文地球—地震学]