初探地震活动的时间分维特征

本文运用分维的概念和方法,对我国部分强震前地震活动时间分维,前震震群活动时间分维,7级以上大地震的余震活动时间分维和小震群活动时间分维进行了计算。初步结果表明,同一类型的地震活动(如强震前较大时空范围内地震活动、强震的余震、前震震群、小震群等类型)的时间分维十分相近,而不同类型地震活动的时间分维存在着差异,一般说来,强震前的地震活动比较普遍地存在降维现象,表现出临近强震时,震源及附近地区地震活动时间结构的有序性增强。这为地震预报开辟了一个新的途径。

A PRELIMINARY STUDY ON TEMPORALLY FRACTAL CHARACTERISTICS OF EARTHQUAKE ACTIVITIES

In this paper, using the fractal concept and method, tut temporally fractal dimensions of earthquake, activity before some strong events in China, fore-shock swarm- activity, aftershock activity of great M>7.0 events and small swarm activity have been calculated. The preliminary results indicate that the temporal fractals of a same type of earthquake activity (such as the earthquake activity within, a comparatively large temporal-spatial scale before a strong event, aftershocks of a strong event, foreshock swarms and small swarms etc.) are very much similar. The temporal fractals of different types of earthquake activities, however, show discrepancy. Generally speaking, there often exists a downfall dimension phenomenon of earthquake activity before a strong event, suggesting an increasing orderliness of temporally seismic structure in the source area and its vicinities at the time of impending a strong event. This has opened a new road to make earthquake predictions.