Three-dimensional reverse-time migration of teleseismic receiver functions using the phase-shift-plus-interpolation method
Three-dimensional reverse-time migration of teleseismic receiver functions using the phase-shift-plus-interpolation method
复制标题
相移加插值法远震接收函数三维逆时偏移
DOI：
10.1093/gji/ggz066
复制
发表时间：
2019
影响因子：
2.8
通讯作者：
Rong Huang
中科院分区：
文献类型：
--
作者：
Xiaohuan Jiang;Lupei Zhu;Shaoqian Hu;Rong Huang
遥测接收函数（RF）常用于确定地壳和上地幔中地震不连续面的深度。我们开发了一种有效的逆时偏移（RTM）方法，直接应用于接收机的功能。一次P-S转换相位及其在RF中的地壳多次波均可用于地震不连续面成像。该方法采用相移加插值算法外推三维速度模型中的震源和接收器波场，与全波方程数值解相比，大大降低了计算量。在多种地壳模型中的试验结果表明，该方法是有效的，且优于共转换点叠加方法。特别是，该方法正确地处理了由强烈的横向结构变化引起的衍射，并且对界面的最大倾角没有限制。我们将该方法应用于美国中部瓦巴什山谷地震带的线性阵列的真实的数据，并获得了一个失败的大陆裂谷的地壳结构图像。我们建议，未来的被动源地震记录实验地壳尺度成像使用的站间距小于5公里，和一个2-D阵列，甚至更小的站间距是需要强的横向结构变化的地区。随着越来越多的传感器用于被动源记录实验，现在，我们的RF-RTM方法可以是一个有用的工具，从沉积盆地，地壳岩石圈的尺度上的结构成像。
Teleseismic receiver functions (RFs) are frequently used to determine depths of seismic discontinuities in the crust and upper mantle. We developed an efficient reverse-time migration (RTM) method that is applied to teleseismic receiver functions directly. Both the primaryP-to-Sconverted phases and their crustal multiples in RFs can be used for imaging seismic discontinuities. The method uses the phase-shift-plus-interpolation algorithm to extrapolate both the source and receiver wavefields in a 3-D velocity model, which greatly reduces the computation costs compared with those using a full wave-equation numerical solver. Tests using synthetic data in various crustal models demonstrate the effectiveness of the method and its superiority over the common-conversion-point stacking method. In particular, the method handles diffraction caused by strong lateral structural variations correctly and there is no limitation on the maximum dip of the interface. We applied the method to real data of a linear array in the Wabash Valley Seismic Zone in the central USA and obtained a crustal structural image across a failed continental rift. We suggest that future passive-source seismic recording experiments for crustal scale imaging use station spacing less than 5 km, and a 2-D array with even smaller station spacing is desired for regions with strong lateral structural variations. With increasing numbers of sensors used in passive-source recording experiments nowadays, our RF-RTM method can be a useful tool for structural imaging on scales ranging from sedimentary basins, crust to lithosphere.