基于余震信息的宏观震中和影响场方向快速判定方法——以云南地区为例*

(1.云南省地震局,云南 昆明 650224; 2.昆明市西山区防震减灾局,云南 昆明 650118)

余震; 宏观震中; 影响场方向; 一元线性回归模型

Rapid Assessment of the Macro-epicenter and Earthquake-effected Field Based on Aftershocks:a Case Study of Yunnan Area
BAI Xian-fu1,DAI Yu-qian2,LI Yong-qiang1,ZHU Yue-fen1,

(1. Earthquake Administration of Yunnan Province,Kunming 650224,Yunnan,China)(2. Earthquake Administration of Xishan District,Kunming City,Kunming 650118,Yunnan,China)

aftershocks; macro-epicenter; Isoseisma direction; simple linear regression

备注

选取了1966年以来云南地区22个MS≥6.0震例的地震影响场和余震序列,对两者的关联度进行空间统计分析。将余震分级后按2小时递增进行时段划分,然后用一元线性回归方法对各组余震数据进行线性模型回归。采用自变量极值法控制回归直线的范围,将得到的回归线段中点判定为宏观震中,线段方向判定为影响场方向。结果 表明:此方法判定的结果总体上比较接近各震例的宏观震中和影响场方向。

Collecting the isoseismal map and aftershocks of 22 earthquake events(M≥6.0)occurred in Yunnan since 1966,we studied a method for the rapid assessment of the macro-epicenter and earthquake-effected field. Firstly,we classified the aftershocks by magnitude and time into different groups,then we calculated the data of every group by simple linear regression. Controlling the length of regressive line through Variable Extreme Value method,we regarded the middle point of the regressive line as the macro-epicenter,and the line's direction as the isoseisma's direction. The results are generally in line with the data got by the field survey.