闽台地区地震活动的广义时空分维特征

本文根据广义分维方法，分析计算了１９７２年以来福及其周边地区ＭＬ≥５．０级地震，台湾地区Ｍｓ≥７．０级地震前后小震活动广义时间分维和广义空间分维的变化特征。结果表明，闽台两地中强震前普遍存在着Ｄｔ，Ｄｓ的低值异常，福建地区中强震前２ａ左右完成降维过程，而台湾地区则有强震前１ａ左右结束异常。

Characteristics of generalized temporal and spatial fractal dimension before and after mid-strong earthquakes in Fujian and Taiwan

This paper,uses the generalized fractal dimension method to analyze the changes of gen eralized temporal (D_t) and spatial (D_s) fractal dimension of small seismic events around the epicenter before and after earthquakes of larger than 5. 0 in ML value in Fujian and of larger than 7. 0 in Ms value in Taiwan. The results show that low value anomaly of D_t and D_s is widely detected before mid-strong earthquakes. The course of the low value anomaly was fin ished two years before mid-storng earthquakes in Fujian area and one a before mid-storng earthquakes in Taiwan area. The analysis of the lowering charcteristics of the generallied fractal dimension show at least that one of the both D_t and D_s curves is lower than several year's standard square error line before earthquake, meanwhile, the other synchronously lower than average value line. It can be used as a standard of anomaly identification. The results indicate that the generalized temporal and spatial fractal dimension method can well re flect Fujian and Taiwan's seismic tendency in intermediate and short terms.