叶秀薇, 黄元敏, 胡秀敏, 刘锦. 2013: 广东东源MS4.8地震序列震源位置及周边地区P波三维速度结构. 地震学报, 35(6): 809-819. DOI: 10.3969/j.issn.0253-3782.2013.06.004
引用本文: 叶秀薇, 黄元敏, 胡秀敏, 刘锦. 2013: 广东东源MS4.8地震序列震源位置及周边地区P波三维速度结构. 地震学报, 35(6): 809-819. DOI: 10.3969/j.issn.0253-3782.2013.06.004
Ye Xiuwei, Huang Yuanmin, Hu Xiumin, Liu Jin. 2013: Location of the Dongyuan MS4.8 earthquake sequence of Guangdong and 3D P-wave velocity structure in and around source region. Acta Seismologica Sinica, 35(6): 809-819. DOI: 10.3969/j.issn.0253-3782.2013.06.004
Citation: Ye Xiuwei, Huang Yuanmin, Hu Xiumin, Liu Jin. 2013: Location of the Dongyuan MS4.8 earthquake sequence of Guangdong and 3D P-wave velocity structure in and around source region. Acta Seismologica Sinica, 35(6): 809-819. DOI: 10.3969/j.issn.0253-3782.2013.06.004

广东东源MS4.8地震序列震源位置及周边地区P波三维速度结构

Location of the Dongyuan MS4.8 earthquake sequence of Guangdong and 3D P-wave velocity structure in and around source region

  • 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3 km×5 km. 震源区地壳结构复杂, 埋深712 km处为一个速度达6.2 km/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16 km). 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.

     

    Abstract: In this paper, we determined the location of Dongyuan MS4.8 earthquake sequence on 16 February 2012 and 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 MS4.8 earthquake fits a unilateral fracture model, and ruptured down and westward, with a rupture area of 3 km×5 km. A high velocity zone (HVZ) is at the depth of 712 km, with the velocity 6.2 km/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 16 km, 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.

     

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