台湾大地震活动的模糊时间分维特征

本文用模糊时间分维方法探讨了台湾地区地震活动的时间分布规律。结果发现,“大地震”活动的时间序列与分维持征间有良好对应关系。台湾东,西地震带自本纪纪以来划分的４个“大地震”活动高潮时段前,都有一段时显维过程。可以认为,分维特征较好地反映了台湾地区的中长期地震活动趋势。

Temporal characteristics of fuzzy fractal dimension of large earthquakes in Taiwan area

Taiwan Island and its adjacent waters are the region of the highest selsmiclty in China.This paper approaches the law of the seismic activity distribution with time according to the temporal characteristics of fuzzy dimension of earthquakes occurred in Taiwan area. The concepts and computing methods,fractal and fractal dimension,are introduced briefly at first. By using scale transform technique and least-square algorithm,fuzzy fractal dimension of distributoon with time of "large earthquakes" (a fuzzy concept in this paper),which occurred in the seismic zones at the eastern and western Taiwan since this century,have been obtained. The results show that every period of seismicity peak began in the meantime fractal dimension values quickly went up after and obvious dimension reduction process. By M-t diagrams and D. (t) curves, 4 selsmicity peak periods were divided for each of two zones since this century,the western lagging behind the eastern. The results indicate that the temporal characteristics of fuzzy dimension in Taiwan area respond well to Taiwan's mid-term seismic tendency.