辽宁地区中强以上地震时空分布特征

TEMPORAL—SPATIAL DISTRIBUTION OF MODERATE EARTHQUAKES IN LIAONING PROVINCE

对辽宁地区M_s≥4 3/4级地震空间和时间分布特征进行了研究。通过研究认为,郯庐地震带北段是区内最重要的地震带,它控制了辽宁地区的地震活动;渤海北西向地震带和朝鲜新义州—釜山地震带的活动也将会对辽宁地区产生影响,地震活动网络结点、海城地震余震活动区等是未来容易发生中强以上地震的地区。通过熵谱分析、周期图等方法的研究,认为辽宁地区地震活动存在300多年的活动周期,未来百年将处于剩余应变释放期,活动水平不会太高。

This paper presents an analysis of earthquakes with magnitude over 43/4 in Liaoning province. The research results show that the north segment of Tanlu seismic Zone as the most important seismic zone has controlled earthpuake activity in liaoning area. The earthquake activity of Bohai seismic zone and of Xiufu seismic belt have also a greater influence on seismicity in Liaoning region. The intersections of earthquake network and the aftershock area of Haicheng earthquake of M=7.3 are some regions to be prone to occurrence with moderate earthquakes in the future. By the results derived from entropy spectrum analysis and period—graph analysis, it has been found that there exist the seismic activity period with over 300 years in the research area. It is estimated that the seismicity in Liaoning province will be the stage releasing remnant strain, so it is lower in the future.