【摘要】 利用震源位置和速度结构的联合反演,得到2012年2月16日广东东源MS4.8地震序列的震源位置及震源区速度结构模型,并进一步采用双差定位法对该序列位置重新定位.结果显示,东源MS4.8地震是一次自上而下、自西向东的单侧破裂过程,破裂面积约3km×5km.震源区地壳结构复杂,埋深712km处为一个速度达6.2km/s的高速体,主震的起始破裂位置位于高速体的顶部速度梯度较大的区域,破裂面穿越整个高速体,余震止于高速体下方的低速区底部(埋深约16km).东源县锡场镇下方的这种高、低速相间的结构,表明地壳层间相邻物质性状的差异利于应变能的积累和释放,因此东源地区具备发生中强地震的构造条件.更多还原

【Abstract】 In this paper,we determined the location of Dongyuan MS4.8earthquake sequence on 16February 2012and velocity structure of the source region using a simultaneous inversion method.On this basis we relocated the earthquake sequence using the double-difference location algorithm.The results show that the Dongyuan MS4.8earthquake fits a unilateral fracture model,and ruptured down and westward,with a rupture area of 3km×5km.A high velocity zone(HVZ)is at the depth of 712km,with the velocity 6.2km/s.The source rupture started from the top of the HVZ,where the velocity shows a large gradient.The ruptured area cuts across HVZ.All aftershocks are not beyond the lower bound,at 16km,of low velocity zone,which is located below the HVZ.Such a structure of high velocity alternating with low velocity is propitious for strain energy accumulation and release.So Dongyuan region has a crust structure favourable to moderate earthquake occurrence.更多还原