吉林地区平均波速比的测定及研究

THE MEASUREMENT AND RESEARCH OF AVERAGE WAVE VELOCITY RATIO IN JILIN PROVINCE

本文选取2001～2009年吉林省地震观测报告记录的地震事件,根据断裂构造特征和地震的空间分布情况,将研究区域分为四个地区,即西部、中部、东部、长白山火山区。采用多台和达法计算波速比方法研究了吉林地区的波速比分布情况,通过对比发现吉林省西部、中部、东部及长白山火山地区的波速比有明显的变化趋势,即西低、东高、长白山火山区最高,这对吉林地区的地震趋势判断有一定参考意义。文中讨论了2006年吉林乾安-前郭M5.0级地震前后的波速比变化特征,发现该震前出现波速比趋势下降的特征,这对中强地震的短临预测具有实用价值。

In this text,based on the events which were recorded by the seismic observation report of Jilin province from 2001 to 2009,and the condition of the fracture characteristics and the space distribution of the earthquakes,we divide the research areas into four parts：the western part,the central part,the eastern part,and the volcanic area in Changbai mountain.And we have researched the Jilin area distribution of the wave velocity ratio with the multi-station method.Through the comparison we have discovered that there was obvious variation tendency of the wave velocity ratio in the western part,the central part,the eastern part,the volcanic area in Changbai mountain：low in the western part,high in the eastern part,the highest in the volcanic area in Changbai mountain.It＇s meaningful to the earthquake trend estimation in Jilin area.In the paper,we have discussed the varied characteristics of the wave velocity ratio in Qianan-Qianguo earthquake and found the wave velocity ratio had the downtrend.It is very useful for short-time prediction of middle-strong earthquakes.