大地测量与地球动力学2011，Vol.31Issue(2)：17-22,47,7.
2009年姚安Ms6.0地震重力场前兆变化机理
MECHANISM OF PRECURSORY GRAVITY CHANGE BEFORE YAOAN Ms6.0 EARTHQUAKE IN 2009
摘要
Abstract
From the repeted gravimetry data of Dianxi Experimental Field from 2005 to 2009, local differential and cumulate gravity change pictures have been obtained. The study results from the data are as follows. 1 ) The dynamic evolvement pictures of gravity field can generally reflect the movement state of the crustal substance before earthquake. Short-term local effect is obviously reflected by the differential dynamic change, while local tectonic movement and fault structure effect by the cumulate dynamic change. 2)A positive and negative transitional gravity gradient zone across the epicenter along almost north-south direction appeared two years before the earthquake, and a symmetrical four-quadrant distribution of the gravity change appeared too around the epicenter half year before the earthquake. They were the prominent gravity precursor marks of the Yaoan earthquake. 3 ) Durative positive gravity change appeared in the west to the epicenter three years before the earthquake. It was helpfull for energy accumulation. 4)The relatively high-low four-quadrant distribution picture may reflect that there exist a sheafing stress. So we put forward a ‘ lock in shearing force mode’ for the precursor model.关键词
姚安地震/重力场/动态变化/前兆模式/闭锁剪力Key words
Yaoan earthquake/ gravity field/ dynamic change/ precursor model/ lock in sheafing force mode分类
天文与地球科学引用本文复制引用
申重阳,谈洪波,郝洪涛,李辉,杨光亮,玄松柏..2009年姚安Ms6.0地震重力场前兆变化机理[J].大地测量与地球动力学,2011,31(2):17-22,47,7.基金项目
国家社会公益项目(2005DIB3J120) （2005DIB3J120）
地震科学联合基金(A07030) （A07030）
国家自然科学基金(40574012) （40574012）
