中国及其周邻地区中深源地震的活动特征分析

Characteristics Analysis of Moderate-deep Focal Earthquake Occurred in China and Neighbouring Region

根据USGS最新的 7万多条地震资料 ,分析了中国及其周邻地区的地震深度特征 ,特别是 4个中深源震区的深度特征。结果表明 :中国及其周邻四大中深源地震区多位于各板块的交界带上 ,地震活动强度最大的地区为吉林—日本深震区 ,其次为台湾中深震区 ,中印缅交界区和新疆—兴都库什中深震区的地震强度相当 ;并且后面两者的地震频次在 5 5km ,110km和 2 2 0km左右深度出现了多震层位式的高值 ;由深度资料推断板块间的作用方式来看 ,太平洋板块向欧亚大陆的挤压是一个由浅入深的过程 ,在不同的部位有不同的俯冲角度 ,印度板块向欧亚大陆的推挤 ,表现为前者垂直插入后者之中 ,俯冲现象不明显。

According to the latest more than 70,000 seismic recordings from USGS,the earthquake depth characteristics in China and Neighbouring rengion have been analyzed,especially for the ones in the four regions with moderate-deep focal earthquakes.The results show that the moderate-deep focal areas in China and other four regions nearby are located in the borders of plates.The strongest area for seismicity is Jilin-Japan deep seismic zone and the next is Taiwan moderate-deep focal zone.The seismic strength in the border area of China-India-Myanmar corresponds to the one in Xingdukushi moderate-deep focal area.Furthermore,the high values of depths of 55km,110km and 220km appeared in the latter two.It can be seen from the functional pattern between the plates of depth data that the compression of the Pacific Plate to the Eurasia is a process from shallow to deep.There are different dive angles in different parts. The compression of the India Plate to the Eurasia shows that the former inserts under the latter and no obvious diving phenomenon.