存在低速层条件下天然地震波传播射线特征分析

Analysis on natural earthquake propagation radiation path under the presence of low speed layer

依据弹性波动理论,多层地壳介质模型中,天然地震波传播路径及走时满足Snell定律.假设地震发生在地壳中某一深度且地幔中存在低速层,可推导出震源至地面的纵波(P波)射线路径及走时方程.依据该方程考察分析了低速层存在对P波传播路径和走时的影响,研究结果对地壳结构预测提供依据.

According to the elastic wave theory,the natural seismic wave propagation path and travel time satisfy the Snell law in the multilayered crustal medium model.Assuming that earthquakes occur at a certain depth in the earth's crust and a low velocity layer exists in the mantle′the P wave ray path and travel time equation of the source to the ground can be derived.Based on the equation the influence of the low velocity layer on the propagation path nd travel time of the P wave is investigated.The results of the study provide the basis for the prediction of the crustal structure.