2011日本东北大地震前震余震重力效应分析  

Study on coseismic gravity changes of foreshock and aftershocks of 2011 Tohoku-Oki earthquake

作　　者：龚正[1] 许才军[1] 

机构地区：[1]武汉大学测绘学院,武汉430079

出　　处：《测绘科学》2015年第12期59-62,共4页Science of Surveying and Mapping

基　　金：国家自然科学基金重点项目(41431069);国家973项目(2013CB733304);地球空间环境与大地测量教育部重点实验室测绘基础研究基金项目(13-02-08)

摘　　要：针对2011年日本东北大地震(Tohoku-Oki地震)发生前后较短时间内的多次较大前震和余震和主震混在一起,不利于提取出主震同震信号的问题,该文利用弹性位错理论模拟计算了Tohoku-Oki地震一次较大前震和两次较大余震的同震重力变化,讨论了这3次地震单独和综合的重力效应,并与主震重力变化对比分析,认为这3次前震和余震引起的重力变化数值较大,影响范围广,会直接影响到Tohoku-Oki地震主震的同震重力信号提取,所以需要作为重要误差考虑。As some big foreshock and aftershocks occurred shortly before and after the 2011 Japan Tohoku-Oki earthquake,it is a big challenge to extract coseismic gravity signal of mainshock from global monthly gravity field due to its long period.In this paper,elastic dislocation theory was used to simulate coseismic gravity changes of one big foreshock and two big aftershocks of Tohoku-Oki earthquake.Then the individual and the mixed gravity changes of these three events were discussed and compared to coseismic gravity change of the mainshock.With significant magnitude and area,the gravitational effects of these three events would be the important disturbance during extracting the mainshock gravitational signal.

关 键 词：同震重力变化 弹性位错理论 日本东北大地震 前震 余震 

分 类 号：P315.726[天文地球—地震学]