Finite Difference Approach to Seismic Wavefield Modeling Across the Hawaii-Emperor Ridge
Description:
Volcanic seamount chains are widespread throughout ocean basins. P-wave travel time tomography allows for imaging the interiors of these volcanoes, but that requires proper waveform identification of seismic phases that propagate across complex volcanic structures. Current limitations on the number of seismic phases included in tomographic analyses results in less detailed images and a poorer understanding of geological structures than may be possible. In previous studies (Dunn et al., 2019; Watts et al., 2021; Xu et al., 2022; MacGregor et al., 2023), several seismic phases were identified in recorded sections collected along the Hawaiian-Emperor Chain. However, interpreting the origins of some of these phases remains challenging, and others remain a mystery. In this study, we developed an idealized seamount model based on the seismic structure of Jimmu Guyot (Xu et al., 2022) and calculate the seismic P-SV wavefield for various source and receiver positions using a finite difference wavefield modeling code (Levander, 1988; Lata and Dunn, 2020). Our goal is to model observed seismograms and identify additional phases, including P-to-S converted waves. We also intend to verify recent tomographic images of the Hawaiian-Emperor Seamount Chain made by travel time inversion via wavefield matching. By resolving any ambiguities and pinpointing new seismic phases, we aim to enhance future seismic images of the Hawaiian-Emperor Chain and contribute to improvements in our knowledge of the nature of specific structures, such as volcanic cores (a high-density and high-wave-speed interior core of the seamount), the hypothesized magmatic underplating of the oceanic crust by mantle melts rising beneath the volcanic chain, and the nature of the Moho and oceanic crust beneath these volcanic edifices.
Session: Earth’s Structure from the Crust to the Core [Poster Session]
Type: Poster
Date: 5/2/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Megumi
Student Presenter: Yes
Invited Presentation:
Authors
Megumi Fujimoto Presenting Author megumif7@hawaii.edu University of Hawaii at Manoa |
Robert Dunn Corresponding Author dunnr@hawaii.edu University of Hawaii at Manoa |
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Finite Difference Approach to Seismic Wavefield Modeling Across the Hawaii-Emperor Ridge
Category
Earth’s Structure from the Crust to the Core