【摘要】 本文以震群型的邢台大震序列、主震—余震型的唐山大震序列、前震—主震—余震型的海城大震序列为例,取余震区中的余震来研究强余震前的b值异常变化。结果发现,强余震前的b值确实发生异常变化,其变化形态与大震前b值在较大区域内的变化相似,即震前有个明显的峰值期。而且,这种变化形态与地震序列类型无明显的关系。强余震与大震前b值变化的相似性,可能表明发生在余震区中的强余震也经历着与大震孕育发展的类似过程。但孕震时间比大震短。利用余震区内的强余震震前的b值异常变化,可对大震后不太长的时间内的强余震进行临震预测。更多还原

【Abstract】 This paper took the strong Xin Tai earthquake sequence which was the swarm type, the great Tangshan earthquake which was of the main shock-after shock type and the Haicheng earthquake which was of the foreshock-main-after shock type as example and usig aftershock data in the aftershock areas to study the anomalous variations of b-values before a strong aftershock. The result showed that before a strong aftershock the b-values did have anomalous variations, the variation form of which was quite similar to those of the b-values before a strong aftershock in a much larger area, namely, there had been a period with obvious peak values. And there was no clear-cut correlations between the variation form and the sequence mode. The similar b-value variations both before the strong aftershock and the main shock might suggest that the strong aftershocks occurred in the aftershock area were undergoing a similar process of earthquake development just like that occurred for the strong main earthquakes. Yet, the time for carthquake development of the strong aftershocks was much shorter than that of the strong main shocks. On the basis of the anomalous b-value variations before a strong aftershock in an aftershock area, it is possible to predict the strong aftershocks within not a too long period after a main shock.更多还原