地震活动是岩石圈构造变动的突出表现。按地震发生的构造环境和地理分布,地球地震活动可分属于三大地震构造系统,(1)环太平洋地震构造系;(2)洋脊地震构造系和(3)大陆地震构造系。众所周知,除了环太平洋是全球地震活动最密集的地带而外,再就是陆壳分布区。亚、欧、美、非和澳洲各大陆内均有浅源地震活动,但它们突出地集中分布在北纬20—50°之 Seismic activity is a prominent manifestation of changes in the lithospheric structure. According to the tectonic environment and geographical distribution of earthquakes, Earth’s seismic activity can be divided into three major seismotectonic systems: (1) the Pacific Rim Seismotectonic System; (2) the Ocean Ridge Seismotectonic System; and (3) the Mainland Seismotectonic System. As we all know, except the Pacific Rim is the most intensive seismic activity in the world, and then the continental crust distribution. There are shallow earthquakes in all continents in Asia, Europe, the United States, Africa and Australia, but they are prominently concentrated at 20-50 ° N