前兆起伏加剧与短临地震预报

起伏加剧是相态突变前的一种临界现象,本文应用这一观点探讨了强地震前小震活动频次和地下流体、气体、地应力等前兆变化的起伏加剧现象,并得到以下初步结果: 1.临近强地震前较大范围内超过平均日活动水平的小震活动的空间分布具有有序性,即出现穿过未来大震区的小地震活动条带,条带的交汇区为未来大震区。2.强地震前的小震高频次活动日大多与外因出现时间同步,目前发现的外因有塑望、节气、中强以上磁暴以及大气压力下降等。这种小震的高频次活动一般出现在震前当天至一个月时间内。3.前兆的起伏时间和小震频次的起伏时间大致同步。它们在成因上有联系。

PREMONITORY FLUCTUATION AGGRAVATION AND IMPENDING EARTHQUAKE PREDICTION

Fluctuation aggravation is a kind of critical phenomenon before suddenly phase cnange. In this paper we discuss premonitory fluctuation aggravation before strong earthquake at this point, such as small earthquake frequency, underground fluid, gas and earth stress and so on. The preliminary conclusions are as followss:1. Before strong earthquake, the space distribution of small earthquakes which exceed average day active level in a large area is of the orderliness-the active belts of small earthquakes pass through the coming strong earthquake area. The intersecting area of two belts is the site of coming strong earthquake.2. Before strong earthquake, most of the high frequency day of small earthquakes synchronize the time of the external causes, the external causes that are found at present include syzygy, solar term, magnetic storm exceeding middle level, and atmosphere pressure fall and so on. This kind of high frequency activity of small earthquakes usually appears a month or a day before the coming strong earthquakes.3. The time of the premonitory fluctuation and the time of small earthquake frequency fluctuation are approximately synchronization, there are relations between them in the cause of formation.Impending prediction indexes of earthquake as stated here are not only applicable to the many foreshork area, but also to few foreshork area. Because there are many times of premonitory fluctuation before strong earthquake, it is not possible to completely eliminate false for the time prediction of the strong earthquake.