基于GRACE卫星和地表流动重力的汶川M_(S)8.0地震前重力时空变化  

Spatiotemporal variation of gravity detected by GRACE satellite and surface mobile gravity before the Wenchuan M_(S)8.0 earthquake

作　　者：王伟力[1,2] 郑兵 舒东林[1] 曾涛 易松泉[1] 马伶俐 苏琴[1] WANG Weili;ZHENG Bing;SHU Donglin;ZENG Tao;YI Songquan;MA Lingli;SU Qin(Crustal Deformation Monitoring Center of Sichuan Earthquake Agency,Yaan 625000,China;Chengdu University of Technology,Sichuan Province 610059,China)

机构地区：[1]四川省地震局地壳形变观测中心,雅安625000 [2]成都理工大学,四川610059

出　　处：《地震地磁观测与研究》2021年第4期94-100,共7页Seismological and Geomagnetic Observation and Research

基　　金：中国地震局监测、预报和科研三结合课题(项目编号:3JH-202001079)。

摘　　要：利用GRACE卫星重力场模型和地表流动重力观测资料,计算2008年汶川MS 8.0地震发生前6年的重力变化,对卫星和流动重力段差结果与卫星重力反映的重力场动态变化特征进行研究,结果表明:①GRACE卫星重力段差受滤波半径影响显著,与地表流动重力观测结果相比,在重力变化数值上差异较大,在变化率上较为一致;②在汶川地震孕育阶段,川滇地区重力等值线呈“增大—减速增大—减小”的特征,震前2年形成近似垂直于龙门山断裂带的重力变化梯度带。Using GRACE gravity field models and ground mobile gravity data,the gravity variation in the Sichuan-Yunnan area 6 years before the Wenchuan MS 8.0 earthquake is calculated.The variation characteristics of satellite and mobile gravity section differences are compared and analyzed.The dynamic variation characteristics of the gravity field in this area are analyzed.The results show:①The gravity section difference of the GRACE satellite is significantly affected by the filter radius.Compared with the results of mobile gravity observation,the differences in gravity values are big while the variation rate is relatively consistent;②The satellite gravity variation characteristics have a close relationship with the gestation and occurrence of the earthquake.There is an“increasing,slowly increasing,reducing”gravity variation characteristic before the Wenchuan earthquake and the trend of high gradient zone of gravity variation is changed to parallel with the fault just two years before the Wenchuan earthquake.

关 键 词：汶川M_(S)8.0地震 流动重力 GRACE重力卫星 重力变化 

分 类 号：P315.726[天文地球—地震学]