地震空间活动性异常的多尺度表示及其对强震时空要素的指示作用

MULTI-SCALE EXPRESSION OF SPATIAL ACTIVITY ANOMALIES OF EARTHQUAKES AND ITS INDICATIVE SIGNIFICANCE ON THE SPACE AND TIME AT-TRIBUTES OF STRONG EARTHQUAKES

基于偄ｔｒｏｕｓ小波变换的噪声腜?,通过小波变换与统计显著性检验模型的有机结合 ,产生了数据图象结构的多尺度支撑表示 .这一表示不仅给出了数据结构在不同尺度的形状和位置 ,而且剔除了噪声对结构的影响 .由于相应的算法对数据结构的先验假设要求不高 ,故这一方法适用于分析结构复杂的数据 .本文将该思路用于地震空间活动性的研究 ,重点探讨了如何识别并描述不同尺度地震空间活动性异常的方法 .以我国西南地区松潘、黄龙、龙陵、盐源等典型地震序列为例 ,分析了不同尺度地震空间活动性异常的结构特征 .研究表明 ,地震活动性异常的多尺度空间结构与强震震中之间存在一定的关系 ,而松潘序列前震活动性异常的时空演化也表现出一定的规律 .

The noise model based on á trous wavelet algorithm produces a multi-scale expression of image through the combination of wavelet transform and a testing model of statistical significance. This kind of expression not only gives the formation and location of image structure on different scales, but also eliminates the influence of noise. Since the algorithm does not need any priori hypotheses, it is suitable for the data with complex structure. The research line is employed in this paper to analyze the spatial activity of earthquake. The method of how to recignize and describe the multi-scale space activity of earthquake is emphatically discussed in this paper. Taking typical sequences in Southwest China as research cases, we systematically study the structure characters of spatial activity of earthquake on different scales. Results show that multi-scale space structure to some extent possesses indicative effect on strong epicenters. And the foreshock anomalies of Songpan earthquake sequence also reveal interesting pattern during the spatial-temporal evolution.