← Back to Sessions

Implications of Multi-Layer High-Vp/Vs Seafloor Sediments Characterized Using Passive Ocean Bottom Seismic Data: Toward Improving Crustal and Mantle Structure Analysis

Description: 

Body-wave analysis of the sub-oceanic crust and mantle structure is often challenged by the response of seafloor sediment layers that overwrite propagating body waves. Kim et al. (2023; JGRse) introduced a novel method to characterize the in-situ structure of the seafloor sediment using teleseismic body waves recorded by ocean bottom seismometers (OBSs). The method resolves the impedance and the Vp/Vs value of each sediment layer, which is important in predicting the strength of the shallow layer reverberations. We show that a single layer model explaining PS-P time and a multi-layer model from the new method show different waveforms in both high- (~1 Hz) and low-frequency (< 0.3 Hz) ranges.

We apply the methodology to data from various OBS arrays in the Pacific to estimate in-situ sediment structures. The sediment models show multiple layers in some regions, including the top water-saturated layer with low S-wave velocity and high Vp/Vs values. The scaling relationship of Vp/Vs to Vp shows higher values than the previously discussed ones (e.g., Brocher, 2005; Hamilton, 1979). Furthermore, the sediment layer model constrained from the body waves exhibit agreement in predicted Rayleigh wave admittance with the sediment model from the Rayleigh wave admittance (Bell et al., 2015). In this presentation, we will discuss how the in-situ high-Vp/Vs multi-layer sediment model differs in predicting the reverberation effects on receiver function analysis for ocean bottom seismometers. Additionally, we will discuss the potential of integrating Rayleigh wave admittance into our body wave approach to enhance the resolution of crust and mantle structure at depths.

Session: Seismology in the Oceans: Pacific Hemisphere and Beyond - I

Type: Oral

Date: 5/2/2024

Presentation Time: 08:30 AM (local time)

Presenting Author: HyeJeong

Student Presenter: No

Invited Presentation: 

Authors