地震孕育过程中形变趋势变化形态的理论分析  

Theoretic Analysis for Tendency Anomalies' Types of Deformation Precursors in Earthquake-Generating Process

作　　者：薛艳[1] 宋治平[2] 宋先月[2] 武安绪[3] 于海英[2] 王小平[2] 

机构地区：[1]中国地震局分析预报中心,北京100036 [2]上海市地震局,上海200062 [3]北京市地震局,北京100081

出　　处：《中国地震》2003年第3期306-314,共9页Earthquake Research in China

基　　金：地震科学联合基金项目 (10 110 5 );国家"十五"科技攻关项目 (2 0 0 1BA6 0 1B0 1- 0 4 - 0 2 )

摘　　要：利用流变介质包体模型理论中体应变解析解计算分析了孕震过程中不同观测点的形态异常特征 ,结果表明 ,硬包体产生的体应变具有明显的 3阶段过程 ,软包体却只有 2个阶段的特点 ,但它们的形态特征不仅都具有象限性与地区性 ,而且还随震中距的不同而不同。岩石实验结果也表明 ,观测点距破裂面的距离不同 ,其形态特征也不同。在理论分析与岩石实验结果一致的基础上 ,分析了张北地震与景泰地震前形变异常的形态特征 ,即具有明显的地区性与象限性 ;并且形态特征随震中距的变化而不同 ;变化幅度也随震中距的增大而减小。基于对形变异常形态特征的理解 ,提出了利用形态特征预测、判断发震地点及孕震状态的思路。Based on the theoretical expression of the rheologic inclusion model, we analyzed the deformation precursors' characteristics for different observation points during the earthquake-generating process. The results show that the bulk-strain produced by strong body has three stages with different characteristics, while that by a soft inclusion has two. Whether a hard inclusion or a soft inclusion, the shapes of deformation precursors not only exists quadrant and regional features, but also are varied in different epicentral distances. The results of rock experiment also show that the deformation shapes of various observation points with different distances to the fracture surface are distinct. Based on the coherence of theoretical analysis and rock experiment, we analyzed the shape characteristics of deformation precursors before the Zhangbei earthquake and the Jingtai earthquake. The conclusion shows that the deformation precursors' shapes have regional characteristics and quadrant feature, and they are varied with different epicenter distances. In addition, their sizes will become smaller with larger epicenter distance. On the basis of the comprehension for the characteristics of deformation precursors' shapes, we proposed an idea how to estimate the location of a strong earthquake occurrence and the state of a earthquake generation by the characteristics of deformation precursors' shapes.

关 键 词：形变异常 形态特征 流变包体理论 岩石实验 

分 类 号：P315[天文地球—地震学]