摘要
当地震波在层状介质中传播,P波通过速度界面时,会产生PP型折射波和PS型折射转换波.本文利用PS转换波与初至P波的到时差,提出一种不需要拾取P波和转换波震相的转换界面偏移成像方法.文中对三种不同的理论模型,在正演计算的基础上,采用了上述方法进行数值计算,计算结果表明,这种方法能够确定转换界面的位置和形态.这一方法的实现将有利于利用天然地震资料研究地球深部结构.
Transmitted PP and converted PS waves are generated when a P-wave propagates through an interface separation two media with large impedance contracts. To avoid the difficulty of picking up transmitted P-wave and converted wave phases, this paper proposed a converted wave migration method by estimating the travel time difference between PS converted wave and PP transmitted wave. To verify its validity, we apply the converted wave PS converted wave PS migration algorithm to synthetic data generated by three forward modeling. The migration results indicate that PS converted wave may be migrated to reconstruct the transmitting interface. This technique is helpful to investigate the deep earth structures by using earthquake data.
出处
《地球物理学进展》
CSCD
2004年第1期148-153,共6页
Progress in Geophysics
基金
中国科学院知识创新项目(KZCX2-112)资助.
