不同模型下爆炸源和层裂源的Lg波特性研究  

The characteristics of Lg waves excited by explosion source and spall based on different models

作　　者：何永锋[1] 李锴[1] 刘炳灿[1] 

机构地区：[1]装甲兵工程学院,中国北京100072

出　　处：《地震学报》2015年第4期640-647,共8页Acta Seismologica Sinica

基　　金：国家自然科学基金(41374068)资助

摘　　要：地下核爆炸区域及远区地震波信号中,有二次源即层裂源的贡献,其对区域震相Lg波具有调制作用.本文利用理论地震图数值模拟方法,分析爆炸源和层裂源在3种典型介质速度模型下的区域震相特征,得到了爆炸源和层裂源所激发的Lg波与介质速度模型的关系,并结合CLVD源所激发的S波随震中距的演化过程,对Lg波的形成机制进行了阐述.结果表明,CLVD源是激发地下核爆炸低频Lg波的主要因素.Spall is defined as a secondary seismic source contributing to regional and far field seismic signals generated by underground nuclear explosions.It can modulate the regional phase,i.e .,Lg waves.This paper analyzed the character-istics of Lg waves excited by explosion source and spall based on three typical crustal models by using numerical simulation of theoretical seismograms,then obtained the relationship between the crustal velocity models and the Lg waves excited by explosion source and spall.To explain the generation mechanism of Lg waves,we investigated the variation of S waves induced directly by compen-sate linear vector dipole （CLVD）source with different epicentral distances.The results indicate that CLVD source plays an important role in generating low-frequency Lg waves by underground nuclear explosions.

关 键 词：地下核爆炸 爆炸源 层裂源 LG波 

分 类 号：P315.31[天文地球—地震学]