广东地震台网水平定位能力评估

(广东省地震局,广州 510070)

广东地震台网;水平定位能力;最小二乘法;台站分布

The Estimation of Horizontal Location Ability for Guangdong Seismic Network
LIN Qingxi,LIANG Ming,YANG Xuan,JIANG Xijiao

(Guangdong Earthquake Agency,Guangzhou 510070,China)

Guangdong Seismic Network;Horizontal location ability;Least square method;Station distribution

DOI: 10.13512/j.hndz.2020.04.07

备注

精确可靠的地震定位结果是地震学研究的重要基础数据,而地震的水平定位精度是评价一个区域台网水平定位能力的重要依据。根据不同时期广东地震台站的几何分布,利用非线性最小二乘法,在假设每个网格点下方发生一个给定震级的地震情况下,计算研究区域网格点下水平定位误差椭球,其最大水平投影即为水平定位精度,从而实现对广东地震台网水平定位能力的理论评估。结果 显示:现阶段广东台网存在较为明显的定位能力薄弱区,分别加入“十二五”和“十三五”测震台站后,粤东、珠三角地区以及粤西地区水平定位能力得到明显的提升。分析以上结果,给出一个未来台网扩建方案,用以整体提升广东台网的水平定位能力。

The accurate and reliable earthquake location results are important basic data for seismological research,and the horizontal location accuracy of earthquakes is an important basis for evaluating the horizontal location capability of a regional seismic network. Based on the geometric distribution of Guangdong seismic stations in different periods and the assumption of a given magnitude under each grid point,the error ellipsoids of horizontal location under the grid points in the study area were calculated by using nonlinear least square method. The horizontal location ability for Guangdong Seismic Network was estimated theoretically by the maximum horizontal projection of error ellipsoids. The results show that there are obvious weak areas of location ability in the Guangdong Seismic Network at this stage. After the addition of seismic stations constructed in the "12th Five-Year Plan" and "13th Five-Year Plan",the horizontal location abilities were improved obviously in eastern Guangdong,Pearl River Delta and western Guangdong. By analyzing the above results,the paper gave a future network expansion plan to improve in horizontal location ability of Guangdong Seismic Network.