Reply to the discussion by Rao and Singh on “Acoustic characteristics on clayey-silty sediments of the South China Sea during methane hydrate formation and dissociation”

This reply addresses the insightful discussion by Rao and Singh regarding our recent publication on the acoustic characteristics of methane hydrate-bearing clayey-silty sediments. We elaborate on the orthogonal geometry of our 3D acoustic transducer system, demonstrating the precise 90° alignment essential for S-wave splitting measurements, and clarify our frequency selection and calibration methodologies. Furthermore, we explain our experimental strategy of utilizing a single specimen to maintain skeleton consistency, thereby eliminating structural heterogeneity during phase transitions. We provide a kinetic explanation for the reduced hydrate saturation observed at high effective pressures (12 MPa), attributing it to compaction-induced mass transfer limitations. Additionally, we integrate the discussers’ microstructural plate-like clay model with our macro-mechanical framework to better describe hydrate cementation and sediment anisotropy. Finally, we clarify that the orientation of our prediction model axes is designed for practical geophysical inversion. These elaborations aim to deepen the understanding of multiphase interactions and acoustic behaviors in hydrate-bearing sediments.