汶川8.0级地震宁夏前兆异常回顾与同震响应特征分析

Review of precursor anomalies and coseismic responsecharacteristics in Ningxia area before WenchuanMS8.0 earthquake

摘要:

对2008年5月12日四川汶川8.0级地震前宁夏地区出现的前兆观测异常进行回溯性分析,从大地震的孕育范围与地震前兆的发展阶段分析认为这些观测异常可能与汶川8.0级地震有关。宁夏地区数字化流体与形变观测资料出现了不同程度的同震响应变化,对比分析其同震响应特征,结果显示宁夏地区前兆观测对汶川8.0级地震表现出南北分区特征。前兆观测异常的出现与同震响应变化的形态特征,反映出了汶川8.0级地震从孕震阶段到发震时刻宁夏地区的应力\|应变状态的变化过程。

Abstract:

This paper made a retrospective analysis on the precursory observation anomalies in Ningxia area before the Wenchuan M_S 8.0 earthquake on May 12, 2008. From the seismogenic range of large earthquakes and the development stage of earthquake precursory, it is considered that these observation anomalies may be related to the Wenchuan M_S 8.0 earthquake. The data of digital fluid and deformation observation in Ningxia area occurred different degrees of coseismic response changes. The characteristics of coseismic response were compared and analyzed, and the results indicated that the precursory observation of the Wenchuan M_S 8.0 earthquake in Ningxia have north-south regional features. The precursory observation anomalies and morphological characteristics of coseismic response in this study reflect the change process of stress\|strain state in Ningxia area from the preparation stage to the occurrence of Wenchuan M_S8.0 earthquake.