广义地震活动窗及其对震前异常过程的跟踪应用

提出了广州地震窗的概念，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，用以消除局部的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的时间的三维信息以跟踪异常过程，结果显示主震

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

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.