Deconvolution of teleseismic recordings for mantle structure
Deconvolution of teleseismic recordings for mantle structure
复制标题
地幔结构远震记录的反褶积
DOI：
10.1111/j.1365-246x.1997.tb00943.x
复制
发表时间：
1997
影响因子：
2.8
通讯作者：
M. Sacchi
中科院分区：
文献类型：
--
作者：
M. Bostock;M. Sacchi
摘要
要描绘详细的地幔结构，往往需要从远震记录的地震记录中分离出震源特征和结构响应。该反卷积问题可以在对数谱域中提出，在对数谱域中，时间域卷积的运算被简化为加法形式。在许多台站记录的多个事件的引入导致一致性方程系统，源时间函数和与源和接收器之间的传播路径相关联的脉冲响应都必须遵守该系统。系统本质上是奇异的，稳定是通过提供源时间函数的初始估计来实现的。尽管存在其他选择，但从与对应于给定事件的一组对准地震记录的奇异值分解中的最大特征值相关联的特征图像中推导出有效的估计。研究了反褶积方案与同时最小二乘反褶积的关系。将该方法应用于加拿大国家地震台网记录的宽带远震P波，证明了包括与上地幔结构有关的次级相在内的有效格林函数的恢复。
SUMMARY
Delineation of detailed mantle structure frequently requires the separation of source signature and structural response from seismograms recorded at teleseismic distances. This deconvolution problem can be posed in a log-spectral domain where the operation of time-domain convolution is reduced to an additive form. The introduction of multiple events recorded at many stations leads to a system of consistency equations that must be honoured by both the source time functions and the impulse responses associated with propagation paths between sources and receivers. The system is inherently singular, and stabilization is accomplished through the supply of an initial estimate of the source time function. Although alternative choices exist, an effective estimate is derived from the eigenimage associated with the largest eigenvalue in a singular-value decomposition of the suite of aligned seismograms corresponding to a given event. The relation of the deconvolution scheme to simultaneous least-squares deconvolution is examined. Application of the methodology to broadband teleseismic P waveforms recorded on the Canadian National Seismograph Network demonstrates the retrieval of effective Green's functions including secondary phases associated with upper-mantle structure.