丽江地区7.0级震前地震序列随潮汐作用的变化特征  

Variation Features of Seismic Sequence under Tidal Effect before M7.0 Earthquake Lijiang

作　　者：吴小平[1] 龚玉兰[2] 黄雍[3] 胡家富[1] 

机构地区：[1]云南大学地球科学系,云南昆明650091 [2]昆明理工大学数理材料学院,云南昆明650041 [3]云南省地震局,云南昆明650041

出　　处：《云南大学学报（自然科学版）》2000年第2期116-119,共4页Journal of Yunnan University(Natural Sciences Edition)

摘　　要：对丽江地区 7.0级地震前 3a内发生的 16 0 5个中小震发震时震源处的潮汐体应力进行了计算 ,按时间进程统计了震源在潮汐体应力的压、张作用下发生的地震所释放能量的平方根的比值 (潮汐体应力压张地震比 ) ,得到了 7.0级大震前丽江地区地震序列在潮汐体应力压张地震比随时间的变化过程 .结果表明 ,在 7.0级丽江大震前的 2a多时间内 ,潮汐体应力压张地震比一直高于 1,距大震前半年开始剧烈升高 ,临震时达到最大 .Tidal body stress at focus points of 1?605 middle and small earthquakes which took place during three years at Lijiang area before M 7.0 shock Feb.3,1996 are calculated.Statistics about the ratio of the square root of seismic energy related with tidal compression to that of seismic energy related with tidal extension are made on time course.Patterns of the ratio variation with time of the earthquake sequence at Lijiang area before the M 7.0 shock are obtained.The result indicates that the value of the ratio was higher than 1 during the time of more than two years before the M 7.0 shock,and began to go up severely at the time six months before the big shock,and reached the maximum just before the shock.

关 键 词：丽江 地震序列 潮汐体应力压张地震比 云南 

分 类 号：P315.7[天文地球—地震学]