广义地震活动窗及其对震前异常过程的跟踪应用  

Generalized seismicity window and its application in tracing the developmental process of precursory anomalies

作　　者：王琤琤[1] 刘红桂[1] 王炜[2] 陈兴东[1] 梅卫萍[1] 张晓勇[1] 

机构地区：[1]江苏省地震局,江苏南京210014 [2]上海市地震局,上海200062

出　　处：《地震》2000年第4期19-27,共9页Earthquake

基　　金：中国地震局"九五"科研攻关项目!(95-0 4 -0 2 -0 4 )部分成果

摘　　要：提出了广义地震窗的概念 ,并以此作为研究范围以突出局部构造特点。用多年地震频次等值线划分广义地震窗的方法 ,在中国东部得到 45个广义地震窗 ,它们具有明显的构造意义。应用原有地震活动参数提出一个相对指标 f,用以消除局部地域特点和地震活动涨落的时段特点 ,提高原指标的异常信息提取能力。用地震活动指数 A(b)值的相对指标 f A( b) ,提出了用多窗异常组合图综合平面和时间的三维信息以跟踪异常过程 ,结果显示主震前存在一定数量的广义地震窗相继出现异常的迁移现象 ,并初步认为其本质是应变波的推进。A concept of generalized seismicity window has been suggested. Investigations have been made within various generalized seismicity-windows to stress local tectonic features. A method of dividing generalized seismicity windows has been proposed on the basis of the average value of earthquake frequency for many years. 45 generalized seismicity windows have been identified in the eastern China. They have obvious tectonic implications. Based on some existing seismicity parameter a relative index f has been proposed to eliminate the influences of local differences and temporal fluctuations of the seismicity, thus enhance our ability to draw more information from the original seismicity parameter. Using the seismicity index A(b) to form a relative index f A(b) , a method of multi window anomaly combination plot combining the three dimensional information of anomalies in time and space has been proposed to trace the developmental process of anomalies. The results show that migration phenomenon of anomalies exists prior to the mainshock, that is, anomalies appear successively in a number of generalized seismicity windows. Advances of strain waves are tentatively considered as the physical nature of this phenomenon.

关 键 词：广义地震窗 多窗异常组合 异常迁移 地震活动 

分 类 号：P315.5[天文地球—地震学]