再论台湾岛及邻近海域强震前的中强地震条带现象及成因初探

摘要

Before ML 7.6 earthquake occurred in Nantou on September 21,1999,an earthquake belt phenomenon occurred in Taiwan Island.Here,the seismic pattern before ML 7.0 earthquake in Taitung overseas on Dec.2004,ML 7.2 earthquake in Kaohsiung overseas on Dec.2006 and ML 6.7 earthquake in Kaohsiung on Feb.2016 is restudied with earthquake belt method in this paper.The result showed that the earthquake belt phenomenon ML ＞ 5.5 had occurred before the three earthquakes mentioned above.It explains that there had existed all earthquake belts before strong earthquake in Taiwan Island and its adjacent waters in recent years.After analyzing the forming cause of these earthquake belts,we consider that the earthquake belt of N-E direction is formed by Philippine plate squeezing.The earthquake belt along the eastern coast of the Taiwan island is formed by seismic fault effect on the east Taiwan island.The earthquake belt along the Ryukyu trench is formed due to the Ryukyu trench fault zone.The result has referent significance for earthquake prediction on the Taiwan Island and its adjacent sea area.%台湾岛1999年9月21日在南投发生7.6级地震前有出现地震条带现象,在2005年工作的基础上继续用地震条带方法对2004年12月台东海外7.0级地震、2006年12月高雄海外7.2级地震和2016年2月6日高雄6.7级地震前的地震图像进行分析发现,这3次地震前也存在ML5.5级以上地震条带现象,说明近年来台湾岛及邻近海域强地震前都有地震条带出现.对这些条带形成的原因进行分析后认为:EN向地震条带是受菲律宾板块挤压形成的,沿台湾岛东部海岸排列的地震条带是受台湾岛东部的地震断层影响形成的,沿琉球海沟方向排列的地震条带是受琉球海沟断裂带影响形成的.研究结果对台湾岛及邻近海域的地震预报具有参考意义.