Seismic wave propagation through a low-velocity nuclear rubble zone
Seismic wave propagation through a low-velocity nuclear rubble zone
复制标题
地震波通过低速核碎石区的传播
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
D. Harris
中科院分区：
文献类型：
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作者：
S. Larsen;D. Harris
作为水声核扩散监测项目（ST 639）的一部分，开发了一个二维有限差分程序。该代码用于模拟地震和声波在地壳和海洋水柱中的传播。作为示范，我们调查了地震能量的传播通过一个低速区对应的碎石区由地下核爆炸。模拟震源和地面记录仪器的几何形状代表地震折射勘测。该数值模拟的目的是确定由于在地表可以检测到低速区（核腔）而引起的地震波场扰动。通过空腔的波能明显延迟，并且在P和S波场的横截面上容易观察到。在地面记录的合成地震图表明，与穿过空洞的射线路径相对应的那些台站的振幅减小和相移。相当一部分能量被低速区反射，并作为反向行波传播。
A 2-dimensional finite-difference code has been developed as part of the Hydroacoustic Nuclear Proliferation Monitoring Project (ST639). This code is used to model seismic and acoustic wave propagation in the Earth`s crust and oceanic water column. As a demonstration, we investigate the propagation of seismic energy through a low-velocity region corresponding to the rubble zone created by an underground nuclear explosion. The geometry of the simulated source and surface recording instruments is representative of a seismic refraction survey. The purpose of this numerical simulation is to determine perturbations in the seismic wave field due to the low velocity region (nuclear cavity) can be detected at the surface. Wave energy passing through the cavity is noticeably delayed, and is easily observed on cross-sections of the P and S wave fields. Synthetic seismograms recorded at the surface demonstrate an amplitude reduction and phase shift for those stations corresponding to ray-paths through the cavity. A significant fraction of energy is reflected off the low-velocity zone, and propagates as backward traveling waves.