Abstract: Abstract The spatial distribution of m_b≥5.0 earthquakes and their focal mechanis solutions havebeen studied for the southern Taiwan─philippines area by use of ISC seismic data,as well as thepatterns of the subduction zone and the stress state in the crust and subduction zone along withthe other resuIts from the geophysical studies.It is considered that the eastern boundarv of theSouth China Sea plate consists of such subduction zones as southwestern Taiwan,Manila,Negrosand Cotabato.The western boundarv of the Philippines plate consists of the subduction zones ofEast Lazon trough and Plilippine Sea.The Philippine Islands are a transitional zone of being deformed.In the presence of that transitional zone,the South China Sea subplate has subducted beneath the Philippine Islands and the Philippine plate has a weak effect on the southern part.Key works：Subduction zone,Stress field,Plate movement,Focal mechanism solution,Taiwan,Philippines

Key words: Subduction zone, Stress field, Plate movement, Focal mechanism solution, Taiwan, Philippines

摘要： 利用ISC地震资料研究了台湾南部～菲律宾群岛的地震空间分布和m_b≥5.0的机制解,讨论了俯冲带的形态和地壳及俯冲带上的应力状态,并结合地质和地球物理的研究结果,认为南海次板块的东部边界是由台湾西南俯冲带、马尼拉俯冲带、内格罗斯俯冲带、哥达巴都俯冲带组成,菲律宾海板块的西部边界由东吕宋海槽俯冲带、菲律宾海俯冲带组成。菲律宾群岛是一个形变过渡带,由于该过渡带的存在,南海次板块俯冲于菲律宾群岛之下,菲律宾海板块对南部的影响很弱。

关键词: 俯冲带, 应力场, 板块运动, 地震机制解, 台湾, 菲律宾