2024/12/11 by Young H. Kim, Hitoshi Kawakatsu, Takeshi Akuhara +7 · 1 voice
Earth and Planetary Sciences · Environmental Science · #Methane Hydrates and Related Phenomena #Seismic Imaging and Inversion Techniques #Seismic Waves and Analysis
paper · pdf · doi:10.1093/gji/ggae444
openalex publication_date 2024/12/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/27
SUMMARY This study presents the velocity structures of the seafloor sediment across the Pacific using teleseismic body waves recorded by arrays of ocean bottom seismometers (OBSs). We apply the method inverting the multicomponent stacked autocorrelation functions and radial-component waveform of teleseismic body waves. We analyze OBSs distributed across the Pacific Ocean, through a wide range of water depths and equipped with various sensor types. The inverted models agreeing with measurements of seafloor drilling samples demonstrate the broad applicability of employing the inversion method to resolve sediment thicknesses ranging from <100 m to a few kilometers. In addition to various broad-band OBSs, we confirm our method works also for short-period sensors, since our retrieved the model using data from a short-period sensor in Northeast Japan agrees with active-source seismic survey analyses. The constrained models show various numbers of intrasediment discontinuities across different locations. Furthermore, the newly characterized sediment models have higher values of P-wave to S-wave velocity ratio (VP/VS) than the previously known scaling relationships, which suggests a larger effect of sediment-layer reverberation on the body-wave analysis than we have anticipated. The sediment velocity models obtained in this study produce Rayleigh-wave admittances that are consistent with those in previous studies but with much finer structural details within the sediment layer. The reverberation waveform inversion method will enable improved predictions of the impact of the water and sediment layers in body-wave records from existing and future OBS observations.