垂直形变震后效应与地震前兆的识别  

DISCRIMINATION BETWEEN POST-SEISMIC EFFECT AND EARTHQUAKE PRECURSOR OF VERTICAL DEFORMATION

作　　者：张四新[1] 刘立炜[1] 祝意青[1] 

机构地区：[1]中国地震局第二监测中心,西安710054

出　　处：《大地测量与地球动力学》2013年第6期5-9,共5页Journal of Geodesy and Geodynamics

基　　金："十二五"国家科技支撑计划项目(2012BAK19B01-01)

摘　　要：针对大震后出现的垂直形变震后效应与地震前兆判断的不确定性问题,利用昆仑山口西8.1级、汶川8.0级地震前后青藏块体东北部的区域水准、跨断裂水准资料,分析了震后效应与地震前兆所对应形变异常的区别。结果认为:震后效应异常所在区域在大震前大多呈现弱继承性或逆继承性升降差异运动,即区域应力场在大震前大多呈现"弱挤压"或相对"松弛"状态。而地震前兆所在区域在大震前则呈现较强的继承性升降差异运动,即区域应力场在大震前多呈现"强挤压"状态。Discrimination between post-seismic effect and earthquake precursor of vertical deformation after large earthquake was analyzed with the regional leveling and fault-crossing leveling data before and after Ms 8.1 earthquake in Qinghai -Xinjiang area and Wenchuan Ms8.0 earthquake in the northeast margin of Qinghai-Tibet The results show that： Post-seismic effect was reflected by counter-inheritance motion of mountain decreased and basin uplift, it indicates that the tectonic stress field ＂weak compressing＂ or ＂relaxation＂ before big earthquake ; And earthquake precursor of vertical deformation was reflected by inheritance motion of ascending and descending differently, it indicates an intensive trend of tectonic stress field before big earthquake.

关 键 词：垂直形变 震后效应 地震前兆 形变异常 识别 

分 类 号：P315.725[天文地球—地震学]