全球大陆7级浅源大地震强余震震级和空间分布特征

Magnitude and Distance Distribution Characteristics of Strong Aftershocks in Continents of the World

本文收集了1967—2007年全球大陆(不包括中国大陆)29次7.0～7.9级浅源大地震的余震资料。根据震源机制解结果把这29次地震序列分为走滑型和非走滑型,其中17次是走滑型,12次是非走滑型,并分别研究了走滑型和非走滑型地震序列强余震震级分布特征和空间分布特征。研究结果表明,强余震与主震震级差服从指数分布,统计得到了走滑型地震序列B值为0.58,非走滑型地震序列B值为1.07。走滑型地震序列强余震与主震距离的优势分布范围是10～45km,而非走滑型地震序列强余震与主震的距离优势分布为20～59km,并且强余震与主震震中距服从正态分布。

We collect data for 29 earthquake sequences with MS7.0~7.9 from 1966 to 2007 in the continents of world（except China continent）,and then devide them into strike-slip or no-strike-slip earthquake sequences.Seventeen earthquake sequences are strike-slip type and twelve earthquake sequences are no-strike-slip type.We study the characteristics of the magnitude difference distribution between main shocks and their strong aftershocks;and then study the spatial distribution characteristics of strong aftershocks away from their main shocks of the 29 earthquake sequences.The result shows that the magnitude difference distribution obeys intercepted exponential distribution,the B value is 0.58 for the strike-slip type earthquake sequences and 1.07 for the no-strike-slip type earthquake sequences.While the spatial distribution of strong aftershocks obeys normal distribution,the dominated distribution area of strong shocks of the strike-slip type earthquake sequences is 10~45 km and no-strike-slip type earthquake sequences is 20~59 km.