中国大陆西部重力场变化与强震危险性关系

Relationship between gravity variation and seismic hazards in the western China

本文基于中国大陆西部流动重力测量获得的区域重力场变化数据,尝试对其进行多种位场变换,在一定空间尺度约束下定义了6种区域重力场变化指标量.在此基础上,以中国大陆2002年、2005年和2008年等3期数据为研究对象,计算并统计了中国大陆西部MS≥6.0地震震中位置处震前重力场变化及各种导出参数值,尝试初步构建以地震预报为目的的地震重力学科指标体系参数.研究结果表明,震前区域重力场变化与地震发生位置没有显著的统计关系,但是重力场变化的垂直梯度和解析信号模量具有一定的地震预报意义,适合作为地震前兆异常使用.

In this paper,based on the regional gravity field variation derived from the mobile gravity observed data in the western China,we have got the six sorts of gravity variations at each space-fixed cell by means of the potential field transform.On the basis of the six types of variations,taking the three-issue gravity data in the years 2002,2005,2008 as study objects,we computed and analyzed the relationships between the MS ≥6.0 earthquake and the gravity vari-ation with the derived parameters,so that we could try to establish the index system for the purpose of the earthquake forecast.Our study results show that there is no significant relationship between the gravity variation and epicentral location before earthquakes.However,the amplitude of analytic signal and vertical gradient of gravity variation are related to the location of earthquakes happened in future,which can be used for the prediction of the earthquake loca-tion as earthquake precursory anomalies.