【摘要】 本文研究了大华北地区(30°—42°N、106°—125°E)1970—1988年期间12次中强地震前主震附近小震活动的时间分维特征及其与主震之间的关系。表明在12次中强震前主震附近不同时段内165个小震时间序列中,有87个存在分维结构,8次中强震前2年至1年间出现分维值小于0.5的前兆值。同时还研究了35个前震、余震及震群序列的分维特征,发现其中29个存在分维结构。海城前震的分维值为0.432,余震分维值在0.60—0.78之间,震群分维值的优势分布在0.7—0.8之间。更多还原

【Abstract】 This paper studies the time-subdimensional features of activities of small quakes near mainshocks before 12 moderate and strong earthquakes during 1970-1988 in North China (30°-40°N, 106°-125°E) and their relation with mainshocks. It is shown that there existed 87 subdimensional textures in the 165 time series of small earthquakes in various stages near mainshocks before the 12 moderate and strong earthquakes, two to one year prior to 8 moderate and strong earthquakes there appeared precusory value of subdimensional value less than 0.5. Simultaneously, we also studied the subdimensional feature of 35 foreshock, aftershock and swarm series and found that 29 of the 35 had subdimensional texture. The subdimensional value of the Haicheng foreshocks is 0.432, those of the aftershocks is 0.60-0.78 and those of the swarm is 0.7-0.8 predominantly.更多还原