利用克里金技术标定新疆及附近地区P/S震相幅值比及其在地震事件识别中的应用  

CALIBRATION OF P/S AMPLITUDE RATIOS FOR SEISMIC EVENTS IN XINJIANG AND ADJACENT AREAS BASED ON A BAYESIAN KRIGING METHOD

作　　者：潘常周[1] 靳平[1] 肖卫国[1] 

机构地区：[1]西北核技术研究所,中国西安710613

出　　处：《地震学报》2007年第6期625-634,共10页Acta Seismologica Sinica

基　　金：军控核查技术项目(513310101)资助

摘　　要：针对中国的乌鲁木齐台（WMQ）和哈萨克斯坦的马坎奇台（MAK），采用贝叶斯克里金技术建立了新疆及附近地区地震事件的P／S震相幅值比的校正曲面，并分析了校正曲面与地震波传播路径的关系，以及校正曲面对于改善P／S震相幅值比判据识别效果的有效性．分析结果表明，建立的校正曲面基本合理，结合传播路径差异和地震波传播规律，能够较好地解释校正曲面的起伏特征．而且，在传播路径差异较大，使得P／S震相幅值比经震中距校正后离散度仍然较高的情况下，利用校正曲面修正P／S震相幅值比，可以进一步降低其离散度，从而改善判据的识别效果．MAK台lg[Pn（2～4Hz）／Lg（2～4Hz）]校正曲面修正后，对天然地震的误识率由16．3％下降为5．2％．Correction maps of P/S amplitude ratios for seismic events distributed in Xinjiang, China and adjacent areas were established using a Bayesian kriging method for the two seismic stations WMQ and MAK. The relationship between correction maps and variations of along-path features was analyzed and the validity of applying the correction maps to improve performances of P/S discriminants for seismic discrimination was investigated. Results obtained show that obtained correction maps in general may reflect event-station path effects upon corresponding P/S discriminants, and the correction of these effects could further reduce scatters of distance corrected P/S measurements within earthquake and explosion populations as well as improve their discriminating performances if path effects are a significant factor of such scatters. For example, as corresponding kriging correction map was applied, the misidentification rate of earthquakes by lg[Pn（2-4 Hz）/Lg （2-4 Hz）] at MAK was reduced from 16.3% to 5.2%.

关 键 词：地震事件 识别 克里金 P/S震相幅值比 

分 类 号：P315.31[天文地球—地震学]