张北62级地震前京西北地区地震波速比的异常变化  

The abnormal change of wave velocity ratio in northwest of Beijing before Zhangbei 6.2 earthquake

作　　者：刘继禄[1] 张从珍[1] 李雪英[1] 杜迎春[1] 董孝平[1] 

机构地区：[1]河北省地震局,中国石家庄050021

出　　处：《地震地磁观测与研究》2000年第1期6-11,共6页Seismological and Geomagnetic Observation and Research

摘　　要：对张北62级地震前京西北地区地震波速比的时空分布特征进行了分析,发现62级地震前,该地区波速比时空分布都出现了较明显的低值异常:下降—低值—恢复—下降—发震的过程。空间分布则为近似椭圆形的低值异常区,异常区外围地区地震平静。对计算结果进行了t检验,波速比的时空变化及t检验结果表明,62级地震前京西北地区地震波速比存在着比较明显的低值异常。We analysis the time space change of wave velocity ratio in northwest of Beijing before Zhangbei 6 2 earthquake,and find that there is an obvious change,this process includes decline,low value,comeback,decline and happen.The abnormal area in space spread is a ellipse area,and there is a placidity outside the abnormal area.At the end,we check up the statistical result through t test,the result of the abnormal change of wave velocity ratio indicates that there is obvious abnormal low value of wave velocity ratio in northweat of Beijing.

关 键 词：京西北地区 波速比 张北地震 地震波 地震 

分 类 号：P315.31[天文地球—地震学]