摘要
利用地震对分析统计方法研究了川滇木里—宁蒗及松潘一汶川区的地震时空分布图象。结果表明:①任何震级的地震在空间上的分布都是非随机的,不均匀分布。在较小震中距上,地震呈现明显的聚集现象。聚集程度有随震级明显增高的趋势,且随构造背景而异;②两区域的地震(松潘一汶川区3.5≤M≤3.9的子集例外)在时间上的分布也是不均匀的。小震级地震集中在较小时间间距范围上,较大震级地震的分布图象则随区域构造背景及地震活动水平不同而出现较大差异。
Using pair analysis statistics, we studied the spatial and temporal pattern of earthquake distribu- tion of Muli-Ninglang area and Songpan-Wenchuan area in Sichuan-Yunnan Province. It was in- dicated by the results that the spatial distributions of earthquakes for each mangnitude were nonrandom and nonuniform. As for small epicenter distances, the earthquakes were characterized by clear cluste- ing. The clustering degrees increaing with the increase of magnitude were different in diffetrernt tec- tonic setting. In addition, the temporal distributions of earthquakes, except the 3.5≤M≤3.9 subset in Songpan-Wenchuan, were also nonuniform. Small earthquakes appeared clustering at short time intervals, while the pettern of earthquake distribution for larger mangnitudes were rather different as to different tectonic setting and seismicity and seismicity level.
出处
《四川地震》
1991年第2期36-42,共7页
Earthquake Research in Sichuan
