大震前后中强地震活动格局变化及其预测意义初步研究

PRIMARY STUDY ON THE MIGRATE OF LARGE-SCALE SEISMICITY PATTERN BEFORE AND AFTER LARGE EARTHQUAKE AND ITS SIGNIFICANCE FOR PREDICTION

摘要:

从演化的角度研究了1950年以来青藏块体中强以上地震活动大尺度的空间有序性及震后活动格局的转折变化。结果指出,大震前大尺度地震活动时空有序图像的出现是大震孕育过程中的一个重要阶段,对7级以上地震的中期预报具有指示意义;大震后原有活动格局的打破及转折是震后地震演化过程中的一个重要阶段,对未来地震活动的预测具有指示意义。在打破格局的地震及其附近地区继续发生中强以上地震或显著性地震事件的可能性较大;而在1~3年的中期尺度上,这些地区及其附近存在发生7级以上地震的可能。

Abstract:

The large-scale seismicity spatial ordering pattern and the turning characteristics of postseismic activity pattern of moderate-strong earthquake are studied in Qinghai-Xizang block from 1950. The results point out that the appearance of large-scale seismicity spatial ordering before large earthquake is an important stage in the process of strong earthquake development and it can conduct the M_S≥7 earthquake prediction. The breakout or turning of moderate-strong earthquake activity pattern is also an important stage in the process of postseismic activity evolvement, especially the earthquake which breaks down the pattern gives an indication of future seismic activity tendency. There is probability of reoccurring moderate-strong earthquakes or distinct events, and M_S≥7 earthquake in 1~3 year in the region and adjacent areas of earthquake that breaks out the seismic activity pattern.