APPLICATION OF SLANT MOVEOUT CORRECTION IN RECEIVER FUNCTION ANALYSIS

Abstract

Receiver function (RF) analysis is widely used to image seismic discontinuities in the Earth's crust and upper mantle. However, variations in slowness and incidence angle, especially in the presence of dipping interfaces, can cause converted Ps phases to arrive at different times, reducing coherence in stacking and obscuring structural interpretation. This study introduces a slant moveout (SMO) correction method to address this misalignment. The approach is first validated through syn-thetic forward modeling using a 1D velocity model with a dipping Moho interface, simulating converted phases (Ps, PpPs, PsPs+PpSs) across a range of slowness values. The results show significant misalignment before correction and vertical phase alignment after applying SMO correction, leading to enhanced amplitude and clarity in stacked traces. The method is then applied to real teleseismic data recorded from 2012 to 2022 at the UGM seismic station in Yogyakarta, Indonesia, using events of magnitude 7.1–9. Receiver functions are computed after prepro-cessing steps including bandpass filtering, rotation to the LQT system, and time-domain deconvolution. Time shifts are calculated for each trace based on theoretical Ps arrival times using slowness and interface geometry parameters. Af-ter correction, RF gathers show improved coherence near the reference delay time (around 2.4–2.6 s) with more vertical alignment, particularly for slowness between 0.055–0.062 s/km. The applied time shifts range from 0.27 to 1.07 s. Final stacked RFs exhibit clearer Ps phases with sharper onsets, more distinguishable multiples, and enhanced waveform symmetry and baseline stability. These findings confirm that SMO correction improves the temporal resolution and interpretability of RF analysis, especially in tectonically complex regions with dipping structures.