【摘要】 南海东北部地处欧亚板块与菲律宾海板块的交汇区,新构造运动活跃。根据地震活动性、震源机制解和GPS资料对该区的新构造活动特征进行分析,在此基础上讨论该区新构造运动的动力学机制。分析发现,菲律宾海板块NW向俯冲对该区的影响最为显著,导致了该区较强的地震活动性以及与俯冲方向一致的构造应力场。而印藏碰撞产生的侧向应力传递也影响到该区,控制华南地块向SE方向运动,并与菲律宾海板块的NW向俯冲共同作用,使华南地块在SE向运动的同时伴有逆时针旋转。印藏碰撞的SE向应力传递对俯冲产生的NW向水平挤压的抵消作用,使得地震活动性自东向西减弱以及构造应力场P轴方位角顺时针旋转。在这一背景下,区内滨海断裂带的活动控制了该区的地震、海岸带构造升降等新构造运动。更多还原

【Abstract】 The northeastern South China Sea area is tectonically active because of its location in the convergent zone of Eurasian plate and Philippine Sea plate.According to seismicity,focal mechanism solution(FMS) and GPS data,we analyzed the characteristics of the neotectonics in this area,and put forward the dynamic mechanism of the neotectonics.On the basis of these data,it’s suggested that the NW-trending subduction of Philippine Sea plate had stronger impact on the research area relative to the India-Tibet collision,and led to strong seismicity and NW-trending stress field.However,lateral stress transmission resulting from the collision also affected this area,and caused the South China Block to have moved southeastward.Meanwhile,the South China Block rotated counter-clockwise under the combined action of the two.The SE-trending lateral stress transmission counteracted the NW-trending compression produced by subduction and resulted in the westward-weakening seismicity and the clockwise-rotating axis P of FMS.Under this tectonical setting,the Binhai Fault Zone controls the earthquake and coastal tectonic uplift-subsidence of this area.更多还原