2019年8月海南岛三亚地震的控震断裂及未来地震危险性分析

2019年8月20日,海南省三亚市天涯区连续发生两次有感地震.为研究本次地震的控震断裂及琼南地区未来的地震危险性,综合分析了琼南地区历史地震活动特征和主要断裂的构造活动特征.结果表明:近EW向九所-水断裂在琼南地区起主要控震作用,沿断裂带小型地震频繁而密集发生.震中周边的NW向乐东-田独断裂较其他方向断裂活动时代最新,...

Analysis of Earthquake-controlling Faults of Sanya Earthquake on Hainan Island on Aug.,2019 and Future Seismic Risks

On Aug.,20,2019,two earthquakes occurred successively in Tianya District,Sanya City of Hainan Province.In order to study the earthquake-controlling faults and the future seismic risks in Southern Hainan area,we comprehensively analyzed the characteristics of historical earthquakes and the tectonic activity characteristics of main faults in the study area.As the research shows,the Jiusuo-Lingshui fault in near EW-direction plays a major role in controlling earthquakes in southern Hainan,and small earthquakes occur frequently and intensively along the fault zone.Compared with other faults,the NW-direction Ledong-Tiandu fault around the epicenter has the newest activity era,which together with the Jiusuo-Lingshui fault,caused this earthquake jointly.Active faults in this region have not been active since the late Pleistocene.Based on previous studies on stress drop,gravity observation and in-situ stress in Southern Hainan area,it is inferred that the possibility of destructive strong earthquakes in the near future is relatively small.