利用InSAR和GPS数据分析台湾西南两次M_w>6地震的触发关系及应力影响  

Triggering relations and stress effects analysis of two M_w>6 earthquakes in southwest Taiwan based on InSAR and GPS data

作　　者：王乐洋[1] 高华[1,2] 冯光财 WANG Leyang;GAO Hua;FENG Guangcai(Faculty of Geomatics, East China University of Technology, Nanchang 330013, China;State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China;School of Geoscience and Info-Physics Engineering, Central South University, Changsha 410083, China)

机构地区：[1]东华理工大学测绘工程学院,江西南昌330013 [2]武汉大学测绘遥感信息工程国家重点实验室,湖北武汉430079 [3]中南大学地球科学与信息物理工程学院,湖南长沙410083

出　　处：《测绘学报》2019年第10期1244-1253,共10页Acta Geodaetica et Cartographica Sinica

基　　金：国家自然科学基金(41664001;41874001);江西省杰出青年人才资助计划(20162BCB23050);国家重点研发计划(2016YFB0501405)~~

摘　　要：利用InSAR和GPS进行地震研究具有很大的优势,InSAR能够在较大范围内快速地获得连续的同震形变观测,而GPS测量精度高,可迅速获得稳定的测量结果。随着SAR卫星的增多、重返周期的缩短,利用InSAR和GPS联合进行地震触发关系及应力影响研究也变得更为有力。2010年3月4日和2016年2月6日台湾西南部接连发生两次Mw6.0以上地震,分别被称为甲仙地震和美浓地震。本文利用GPS和InSAR同震形变场联合反演了甲仙地震的滑动分布模型;结合之前的研究成果,基于静态库伦应力改变对甲仙地震与美浓地震的关系进行了分析;还为台湾西南部7个主要断层构建了断层格网并获取了它们的应力改变模型。结果表明,甲仙地震的发震断层表现为逆冲倾滑兼一定走滑分量的断层。甲仙地震的主要滑动区域处于12~16km深度之间;最大滑动量为0.61m位于约14km深处。本文线性反演得到的甲仙地震地震矩为2.27×10^18Nm,相当于Mw6.20。甲仙地震后美浓地震的发震断层上应力增值达4.0MPa,应力增加的面积约占推断断层总面积的74%,表明甲仙地震对美浓地震的发生具有十分明显地加速作用。甲仙和美浓地震共同作用下,西侧的左镇断层和新化断层产生了较明显地应力积累。根据应力改变结果,本文认为甲仙地震和美浓地震后,台湾西南部的左镇断层和新化断层都具有较高的危险性,值得持续关注和进一步研究。InSAR and GPS have great advantages in seismic research. InSAR can quickly obtain continuous co-seismic deformation observation in a wide range, while GPS has high accuracy and can quickly obtain stable measurement. With the increase of SAR satellites and the shortening of the return period, it is more powerful to study the seismic triggering relationship and stress effects by using InSAR and GPS jointly. On March 4, 2010, and February 6, 2016, two earthquakes with M w >6.0 occurred successively in southwestern Taiwan, which are called Jiashian earthquake and Meinong earthquake, respectively. Those are two of the three destructive earthquakes that have occurred in the southwestern plain of Taiwan in the last 200 years (the other was the 1946 M 6.1 Hsinhua earthquake). The time and space intervals between Jiashian and Meinong earthquakes are very small. The study of the relationship between them can not only explore the underground structure of the two events but also further understand the triggering relationship between strong earthquakes. In addition, the effect of the surrounding faults after the two events and which faults have high seismic risk are also worth discussing. As no scholar has deeply studied the relationship between the two events and the effect of the surrounding faults, we used the GPS and InSAR coseismic deformation obtained from ALOS to invert the slip distribution model of the Jiashian earthquake. Based on the static Coulomb stress model, the relationship between Jiashian and Meinong earthquake is analyzed. Seven faults in southwestern Taiwan have been constructed and the stress change models of them have been obtained. We analyzed the high earthquake risk area in southwestern Taiwan based on these stress change models. Fault model obtained by InSAR and GPS inversion shows that the fault structures of Jiashian and Meinong events are very similar, both of which are thrust faults with certain strike-slip. The major slip area of the Jiashian event is between 12~16 km which is slightly deep than

关 键 词：甲仙地震 震源参数反演 INSAR 地震触发 静态库伦应力 

分 类 号：P227[天文地球—大地测量学与测量工程]