2016年意大利阿马特里切Mw 6.2地震震源机制InSAR反演  

Source Parameters for the 2016 Mw 6.2 Italy Amatrice Earthquake Revealed by InSAR Observations

作　　者：张庆云 李永生[2] 罗毅[2] 张景发[2] 杨建钦 ZHANG Qingyun;LI Yongsheng;LUO Yi;ZHANG Jingfa;YANG Jianqin(Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics, China Earthquake Administration,Harbin 150080,China;Key Laboratory of Crustal Dynamics,Institute of Crustal Dynamics,China Earthquake Administration,Beijing 100085,China;CNOOC Institute Research,Beijing 100027,China)

机构地区：[1]中国地震局工程力学研究所地震工程与工程震动重点实验室,黑龙江哈尔滨150080 [2]中国地震局地壳应力研究所地壳动力学重点实验室,北京100085 [3]中海油研究总院,北京100027

出　　处：《武汉大学学报（信息科学版）》2019年第1期118-124,共7页Geomatics and Information Science of Wuhan University

基　　金：中央级公益性科研院所基本科研业务专项(ZDJ2017-29,ZDJ2015-15);民用航天项目(D010102);中国地震局项目(Y201711)~~

摘　　要：2016年8月24日,意大利中部阿马特里切(Amatrice)地区发生Mw 6.2地震。采用ALOS-2条带模式和SENTINEL-1A宽幅模式的合成孔径雷达(synthetic aperture radar, SAR)数据分别进行SAR差分干涉测量处理,获取了该地震的同震形变场。结果显示,本次地震造成意大利中部地区发生明显的地壳形变,在雷达视线向最大沉降量达19.6 cm。基于合成孔径雷达干涉测量(interferometry synthetic aperture radar,InSAR)和GPS同震形变场数据对此次地震的发震断层进行联合反演,通过改进倾角和平滑系数获取方法,得到了最优滑动分布模型。通过使用单断层模型和双断层模型进行反演可知,双断层模型反演结果优于单断层反演结果,两种模型下反演模型相关系数分别为0.85和0.89,发震断层走向分别为160°和158°,倾角分别为44°和46°,倾滑分布主要位于地下5~7 km,平均倾滑角为-80°,最大倾滑量0.9 m位于地壳深度5 km处,该发震断层是亚平宁冲断带的一部分,为NW-SE向延伸的正断层,断层长约20 km。综合使用地震同震形变场和GPS数据对震源机制进行反演、模拟和分析,获取了高精度的震源参数,可以为分析地震危险性和断层破裂参数等提供数据支持。On August 24,2016, an Mw 6.2 earthquake occurred in Amatrice, central Italy. In this paper, we use the ALOS-2 stripe-mode data and SENTINEL-1 A wide swath data to obtain the coseismic deformation field by differential interferometry processing. InSAR results show that the earthquake caused significant deformation in central Italy. The largest subsidence reached 19.6 cm in the satellite line of sight(LOS) direction. Based on the InSAR and GPS coseismic deformation field data, we use a two-step inversion strategy to carried out the joint inversion of the seismogenic fault and to improve estimation method of the optimal dip angle and smoothness coefficient, and obtain the optimal fault slip distribution model. By using the single fault model and double fault model, the inversion show that the results of the double fault model are better than that of the single fault model. The data-model correlation coefficients of the inversion models under the two models are 0.85 and 0.89, respectively. The strike directions of the seismogenic fault are 160° and 158°, and the dip angles are 44° and 46°, respectively. The slip is mainly distributed at 5-7 km depth. The maximum amount of slip is up to 0.9 m at the depth of 5 km. The seismogenic fault is a 20 km long normal fault striking in the NW-SE direction which is a part of the Apennines fault zone. It shows that using InSAR and GPS data to carry out focal mechanism inversion and simulation analysis can accurately derive source parameters and provide data support for the analysis of seismic risk and fault nature.

关 键 词：意大利阿马特里切地震 亚平宁冲断带 INSAR 震源参数反演 

分 类 号：P237[天文地球—摄影测量与遥感]