从两次溧阳地震认识地震现象的相似性

根据两次地震的烈度分布,认识到地震的震时效应与地震大小——烈度与震级的相似关系确是肯定的。反之,分析了两次地震前具有震兆意义的地震活动图象:震前的空区、广义前震与震群,注意到现象的重现性是很好的(即两次地震前均出现相同的现象),但与震级大小的相应关系并不存在。作者认为后者可能只是一种构造活动的反映而未必与震源有直接的关系。

Journal of Seismology ON THE SIMILARITY OF TWO LIYANG EARTHQUAKES

Two earthquakes occurring in Liyang area with a magnitudes of 5.5 (1974) and of 6.0 (1979), The distance between the two epicenters is not greater than 10 km and their source mechanism are very similar. They provide a good oppartunity for studying similarity of earthquakes. In comparing these two earthquakes, we notice that the shapes of isoseismals of the two earthquakes are almost the same and the difference of intensity between each pair of isoseismal of the two earthquakes is one degree. However, before these two earthquakes the precursory seismicity patterns of this region, such as seismic gaps, preshock swarms show rather good repetivity, but do not vary with their magnitudes. We think that the latter phenomenon may reflect the tectonic structure, but not the characters of the source of main earthquakes, assuming the entire region is subjected to a given stress.