中国陆域近10年地震时空分布统计特征

对中国陆域近10年4级以上地震震中的空间分布和季节分布特征进行了统计分析，从1994年1月到2005年2月间的4级以上地震，共计966次。近10年的地震空间分布与中国陆域历史地震分布基本吻合。中国陆域地震活动与印度板块、太平洋板块及欧亚板块间的相互作用有关，与前者相关的地震位于青藏高原及其外围地区；与后者密切的地震活动集中在中国陆域南海，尤其是台湾省。同时地震活动多围绕断块的周围分布。地震震中较集中地分布在活动断裂带附近、断裂带密集分布地带以及大构造区域的边界地带。地震年际活动的季节统计分析表明，地震高峰期集中出现在春季和秋季，各年地震活动波动性最大，地震距平曲线与地球自转速度变化曲线协同，地球自转速度的季节性变化是影响地震活动的基本因素之一。

Time and Space Statistic Characters on Earthquake in China Last 10 Years

In China, there have been 966 earthquakes that are above 4 magnitudes during the latest 10 years from Jan. 1994 to Feb. 2005. Analysis of the seasonal and spatial distribution features of those epicenters shows that the spatial distribution of the latest 10 years earthquake correspond to that of the past history. There is a close relationship between the earthquake and the tectonic plate activity of Indian tectonic plate or Pacific Ocean tectonic plate. The former earthquakes display in Qinghai-Tibet Altiplano and its outlying zone. The latter earthquakes concentrate in southeast China and the South China Sea, especially in Taiwan Province. To some extent, the earthquake mostly occurs nearby the active fracture zone, the fracture zone dense area, as well as the boundary of the big tectonic zone. The seasonal study of the seismic movement shows that seismic rush - hour appears in spring, and the most fluxional ones are in autumn. The earthquake anomalous curve is similar to the earth rotation speed change curve, and the earth rotation rate seasonal change is one of seismic activity fundamental factors.