Characterizing the sediment properties of subduction systems is essential for comprehensively understanding of subduction dynamics and geometry, and a well-determined sediment structure is crucial for correcting and accounting for its presence in seismic data used to investigate deeper structures. The complexity and variability of the seafloor sediment used to be hypothesized to contribute to along-strike variations of seismicity in Aleutian-Alaska subduction zone. The Alaska Amphibious Community Seismic Experiment (AACSE), designed to sample the subduction zone at the Alaska Peninsula region including the incoming Pacific plate, accretionary wedge and forearc, offers a unique opportunity to test this hypothesis and investigate the role of seafloor sediment in subduction systems. In this study, we use OBS data from the AACSE to measure seafloor compliance and Ps converted wave delay times and integrate them to conduct a Bayesian Monte Carlo joint inversion, aimed at resolving marine sediment and shallow crustal structure.