基于光学影像相关性匹配技术的2023年土耳其M_(W)7.8与M_(W)7.5双强震地表同震变形研究  

Study on coseismic surface deformation of the 2023 Turkey M_(W)7.8 and M_(W)7.5 double strong earthquakes using optical image correlation method

作　　者：康文君 徐锡伟 KANG Wenjun;XU Xiwei(National Institute of Natural Hazards,Ministry of Emergency Management of China,Beijing 100085,China;Key Laboratory of Compound and Chained Natural Hazards Dynamics,Ministry of Emergency Management of China,Beijing 100085,China;School of Engineering and Technology,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]应急管理部国家自然灾害防治研究院,北京100085 [2]复合链生自然灾害动力学应急管理部重点实验室,北京100085 [3]中国地质大学(北京),地球科学与资源学院,北京100083

出　　处：《地质力学学报》2024年第2期289-297,共9页Journal of Geomechanics

基　　金：国家自然科学基金青年基金项目(42302257);中央级公益性科研院所基本科研业务专项(ZDJ2021-06);国家自然科学基金地震联合基金项目(U1839204)。

摘　　要：2023年2月6日在土耳其中南部卡赫拉曼马拉什省10个小时内连续发生M_(W)7.8与M_(W)7.5双强震,震源机制解表明两个地震均为走滑型地震。土耳其双强地震发生后,国内外学者利用野外测量、GNSS以及差分InSAR等方法开展了一系列地表同震变形研究,但由于所采用的技术手段限制,当前已有地表同震变形结果尚存在空间分辨率低、近断层处数据缺失等不足。为了弥补这些不足,研究利用哨兵2号光学影像数据,通过影像相关性匹配技术得到了土耳其双强震的东西向和南北向的地表同震变形场,并将这些地表变形转换成为沿着断层方向的左旋走滑位移。变形场结果显示两次地震地表破裂长度分别约280 km和约130 km,首先发生的M_(W) 7.8地震的平均走滑位移量为4.2±1.66 m,最大走滑位移量6.9±0.81 m;随后发生的M_(W)7.5地震的平均走滑位移量为4.9±2.45 m,最大走滑位移量为9.6±1.16 m。通过对比COSI-Corr方法和野外测量得到的水平位移,结果显示2种方法得到的最大水平位移相吻合,而COSI-Corr方法得到的平均位移略大于野外测量得到的水平位移,这是由COSI-Corr方法测量结果中包含了部分离断层弥散变形导致的。研究结论不仅可为断层面滑动反演模型提供变形数据和约束条件,同时可以加深对走滑断裂的破裂行为控制因素的理解。[Objective]On February 6,2023,double strong earthquakes of M_(W)7.8 and M_(W)7.5 occurred consecutively within 10 hours in the Kahramanmaraşprovince in central-southern Turkey.After these double-strong earthquakes,domestic and foreign seismologists studied coseismic surface deformation using field measurements,GNSS,and differential InSAR methods.However,owing to the limitations in the techniques employed,the current coseismic surface deformation results suffer from low spatial resolution and missing data near fault surface ruptures.This study aims to address these limitations and comprehensively present the coseismic surface deformation of the double earthquakes in Turkey.[Methods]Using Sentinel-2 optical image data,the east-west and north-south surface coseismic deformation fields of Turkey’s double-strong earthquakes were obtained using the image correlation method,and these surface deformations were converted into sinistral strike-slip displacement along the fault direction.[Results]The deformation field results showed that the surface rupture lengths of the double earthquakes are approximately 280 and 130 km,respectively.The average strike-slip displacement of the firstM_(W)7.8 earthquake is 4.2±1.66 m;the maximum strike-slip displacement is 6.9±0.81 m.The average strike-slip displacement of the subsequent M_(W)7.5 earthquake is 4.9±2.45 m,and the maximum strike-slip displacement is 9.6±1.16 m.[Conclusion]Comparison of the horizontal displacement results obtained using the COSI-Corr method and field measurements revealed that the maximum horizontal displacements obtained using the two methods are consistent.In contrast,the average displacement results obtained using the COSI-Corr method are slightly larger than the horizontal displacement results obtained using field measurements,attributed to the inclusion of“off-fault”deformations.[Significance]This study not only provides deformation data and constraints for the fault-slip inversion model but also deepens the understanding of factors controlling

关 键 词：土耳其双强震 东安纳托利亚断裂 哨兵2号 光学影像相关性匹配 地表同震变形 恰尔达克断裂 

分 类 号：P315[天文地球—地震学]