广东地区4级左右地震前环境剪应力场的变化  

The variation of tectonic environment shear stress field before moderate and small earthquakes in Guangdong area

作　　者：叶秀薇[1] 闻则刚[1] 杨马陵[1] 康英[1] 

机构地区：[1]广东省地震局,中国广州510070

出　　处：《地震地磁观测与研究》2003年第6期26-32,共7页Seismological and Geomagnetic Observation and Research

基　　金：国家"十五"攻关科技项目;强地震短临预测技术研究2001BA601B-04-03

摘　　要：根据1993年陈培善等导出的峰值加速度、峰值速度和峰值位移与构造环境剪应力场τ0的关系,利用广东省数字地震记录研究了广东地区4级左右地震前后环境剪应力场的变化。结果显示,地震前并未观察到中短期异常变化,以短临变化为主,震前3～15天应力等级显著上升,应力等级相对主震后余震以及较早前的小震都要高,且个别小震平均应力等级大于3这一异常现象。The relations (P.S. Chen et al, 1993) between the peak acceleration, velocity, displacement and the tectonic environment shear stress field τ0 , can be used to estimate τ0 values for small earthquakes. The variation of tectonic environment shear stress field was studied with the data of Guangdong Digital Telemetry Seismograph Network. The result shows the mid-term and short-term anomalies could not be detected before the moderate and small earthquakes, but the short-term and impending anomalies appeared. The value of stress grade obviously raise before the earthquakes 3- 15 days, and the value of stress grade is higher than others which estimated by the aftershocks and the small earthquakes occurred early.

关 键 词：构造环境剪应力场 数字地震记录 地震力学 破裂 

分 类 号：P315[天文地球—地震学]