摘要
为了检验属于板内构造环境的中国大陆是否存在“特征地震”的复发行为,本文研究了10个原地复发强震震源区的震级—频度关系,其中,各震级档的地震频度均按主震之间的时间间隔归一化。结果主要表明:在单一震源或发震断裂段的震级—(对数)累积频度关系图上,中—小地震部分仍然服从于G—R(古登堡—李克特)关系(指数分布);而主要大小的(特征)地震部分明显地离开中—小地震部分的G—R关系曲线,亦即不服从于指数分布或b值模型;在这两个不连续部分之间存在1—2个震级单位的频次“空档”;而代表一个震源区主要大小地震的特征事件,其震级波动大多在0.5个震级单位左右。这些结果与Schwartz和Coppersmith(1984)提出的特征地震震级—频度模式一致。
In order to test whether the recurrence behavior of characteristic earthquakes exists on the Chinese continent which tectonicaily belongs to intra-plate environment, the magnitude—frequency relationships for 10 sources where strong or large earthquakes were repeated have been investigated,Of which the earthquake frequenies of different magnitude ranges have been normalized by the time—interval between or among major events. The results mainly shows that for the plot of magnitude versus (log)cumulated frequency at a single source or a seismogenie fault—segment,the part of moderate and small size events still obeys G—R (Gutenberg—Richter) relation(exponent distribution) ,while the part of mainly size events is far away from the G—R relation curve of the moderate and small events, or does not obey exponent distribution or b value model. One frequent 'gap'which ranges between 1 and 2 units of magnitude exists at between these two unconnected parts. In most cases ,the variation of the magnitudes of the characteristic events which may be representative of the major size earthquakes is about 0.5 unit of magnitude. These results are in agreement with what suggested by the magnitude—grequency relationship model of characteristic earthquakes (Schwartz and Coppersmith, 1984).
出处
《四川地震》
1993年第2期19-28,共10页
Earthquake Research in Sichuan
关键词
地震
震级
频度
震源区
强震
recurrence at same place, magnitude—frequency relationshhip, characteristic earthquake ,Chinese continent
