Waveform Fitting of Receiver Functions for Enhanced Retrieval of Crustal Structure in the Presence of Sediments

Abstract

AbstractThe receiver function technique is widely used to image crustal structure using P‐to‐S converted phases at the Moho discontinuity. However, the presence of sedimentary layer generates additional P‐to‐S conversions and reverberations, which can overprint the Moho phases and pose problems in imaging crustal structure with standard receiver function techniques. We introduce a robust two‐step method that uses H‐κ stacking to determine average thickness and Vp/Vs of the sedimentary layer, followed by waveform‐fitting of the observed receiver function to constrain the average crustal thickness and sub‐sediment Vp/Vs. We tested the method using both synthetic data and real‐data from stations located on sedimentary layers in the Netherlands and USA. We show that the new method outperforms other common approaches in retrieving accurate Moho depth and sub‐sediment Vp/Vs estimates, even in cases where the Moho phases are completely overprinted by large‐amplitude phases related to sedimentary layers.