摘要
本文根据Mandelbrot提出的分形几何学观点,对海城、唐山和松潘三个大地震前后地震(M_L≥3.0)序列,根据其时空分布的总体特征,分析了它们在时间和空间分布上的自相似结构,计算了各自的分维。结果表明:时空分布特征分别类似于一维Cantor集合或一维连续统(?) Cantor集合。并以大震发生为对称点,得到大震前后的分维明显不同。一般大震前,其时空分布具有较低的分维,震后偏高。本文认为,用分维定量描述地震时空分布的复杂性是一个较好的物理量,也许它对未来大震发生的时空预报将起重要作用。
Based on the fractal viewpoint suggested by Mandelbrot,seismic activities (ML≥3.0) are studied for the Haicheng,Tangshan and Songpan earthquakes respectively before and after the occurrence of the large earthquake. The results show that a property of temporal-spatial distribution of seismic activities in a one or two-dimension space has the quality of statistical self-similarity at different length scales. Especially,it has a noninteger fractal dimension less than one or two. And this property is similar to that of one-dimension Cantor set or one-dimes ion continuum (?) Cantor set. In particular,it is found that the fractal dimension is obviously different before and after the occurrence of the large earthquake. In general,that fractal dimension is lower before the quake than after.In this paper,the fractal dimension is considered to be a good physical quantity for describing the complexity in temporal-spatial distribution of seismic activities. Perhaps,it will be of important help in the prediction of large earthquakes.
出处
《地震学报》
CSCD
北大核心
1989年第3期251-258,共8页
Acta Seismologica Sinica
基金
地震科学联合基金
