Impact of velocity model on Moho depth: Insights from receiver function migration in intraplate Gujarat region, India

Understanding Moho characteristics in the Gujarat region is crucial due to its complex geology and tectonic processes in this seismically active intraplate region. This study aims to delineate the Moho depth and examine the impact of various velocity models on it by analyzing seismic data from 58 stations. We utilized the P receiver function migration and H-k stacking techniques with global 1D (IASP91), global 3D (Crust1.0), and local 3D velocity models. Our findings reveal the variations across the entire region; the crustal thickness ranged from 32 to 44.98 km using IASP91, 32.02 to 42.88 km using Crust1.0, and 32 to 41.92 km using the local 3D velocity model. The observed variations in Poisson's ratio ranging from 0.15 to 0.35 indicate heterogeneity in the composition of the crust. A detailed analysis of the impact of the velocity model on Moho depth reveals that when comparing the Crust1.0 model with the IASP91 model, a 3.60% change in V(p )results in a 3.18% change in Moho depth. Similarly, comparing the local 3D velocity model with the IASP91 model indicates a 3.05% change in V-p leads to a 3.03% change in Moho depth. These results indicate that the change in V(p )affects the Moho depth estimations, suggesting the necessity of a high-resolution velocity model to accurately determine the Moho depths. Our findings underscore the robustness of these conclusions and highlight the need for deeper exploration into the geological and tectonic factors influencing crustal properties in the study area.