利用PS-InSAR研究合肥地区活动构造变形  

Using PS-InSAR to study active tectonic deformation in Hefei area

作　　者：董雅竹 谭颖 张朋辉 查显杰[1] DONG YaZhu;TAN Ying;ZHANG PengHui;ZHA XianJie(School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学地球与空间科学学院,合肥230026

出　　处：《地球物理学进展》2021年第5期1822-1833,共12页Progress in Geophysics

基　　金：国家自然科学基金项目(41374037);蒙城国家地球物理野外观测站开放基金(MENGO-202001)联合资助。

摘　　要：合肥地区位于我国大陆中部,其内展布有多条活动断裂,包括著名的郯庐断裂带.由于该地区大部分断裂是隐伏的,其分布位置、活动特性及构造仍存在争议.本文利用PS-InSAR技术处理了合肥地区2017年10月至2019年8月共52景Sentinel-1A卫星升轨SAR数据,获取了该区域的平均形变速率图.我们发现池河—太湖断裂、桥头集—东关断裂和肥中断裂构成的三角形块体内存在与断层活动相关的地壳InSAR形变.利用贝叶斯方法,本文分别对三条断裂附近区域的形变进行了反演.结果显示:池河—太湖断裂的走向为北北东,倾向南东,运动特性以右旋走滑为主兼具少许拉张分量;桥头集—东关断裂的走向为北西,倾向北东,活动特性以右旋走滑为主兼具部分逆冲分量;肥中断裂为一条走向近东西、倾向向南的左旋走滑兼具逆冲运动的断裂.综合三条断裂的运动特征,我们推断该三角形块体受到郯庐断裂的活动和北西方向挤压作用的综合影响,整体有轻微旋转趋势.这可能是该地区小震聚集的原因,应引起足够的重视.The Hefei area is located in the central part of China's Mainland, with many active faults, including the Tanlu fault system. Since most of the faults in this area are blind, their distribution, activity characteristics and structure are still controversial. This paper used PS-InSAR technology to process a total of 52 Sentinel-1 A satellite ascending SAR data from October 2017 to August 2019, and obtain the average deformation velocity map of Hefei area. We found that there are crustal InSAR deformations related to fault activity in the triangular block composed of Chihe-Taihu fault, Qiaotouji-Dongguan fault and Feizhong fault. Based on the Bayesian method, the deformations of three faults were inversed. The results show that the Chihe-Taihu fault is an active fault with a strike of NNE and a dip of SE. Its motion characteristic is mainly right-lateral strike-slip with a small extension component. The tectonic characteristic of the Qiaotouji-Dongguan fault is that the strike is NW and the dip is NE. The movement characteristic is mainly right-lateral strike-slip with small thrust component. The Feizhong fault is a left-lateral strike-slip thrust fault with a strike of EW and a dip of South. Combining the tectonic and motion characteristics of the three faults, we inferred that the triangular block was affected by the activities of the Tanlu fault and the extrusion force from the north-west direction. The whole block has a slight rotation trend, which may be the reason for the occurrence of small earthquakes in this area. And the triangular block area should attract enough attention.

关 键 词：PS-INSAR 断裂构造 地表形变 合肥地区 

分 类 号：P228[天文地球—大地测量学与测量工程]