Sponsored by Phillips 66

Exploring Earth’s Interior with 3D Numerical Seismic Wave Simulations

PROJECT NUMBER: 61

AUTHOR: John Rekoske, Geophysical Engineering | MENTOR: Ebru Bozdag, Geophysics

ABSTRACT

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New advancements in high-performance computing (HPC) and 3D numerical wave equation solvers pose unique opportunities to improve our understanding of the Earth’s interior. A recent study has proposed a new model, EPOC (Irving et al. 2018), for the elastic parameters (density and P-wave speed) of the Earth’s outer core. In this research, we compute 3D synthetic seismograms using the SPECFEM3D_GLOBE (Komatitsch and Tromp 2002) software, where the simulations were run using the Mines’ Wendian HPC system. We tested several different models for the Earth’s outer core (EPOC and PREM), as well as different models for the Earth’s mantle (S40RTS (Ritsema et al. 2011) and PREM (Dziewonski and Anderson 1981)). Using the synthetic seismograms, we compute the cross-correlation to quantify the phase shift observed between the seismograms for specific phases that travel through the outer core. We find that the new EPOC model can result in time shifts of up to 3-4 seconds for seismic phases such as SKS, PKiKP, and PKIKKIKP. These results demonstrate the potential significance of the outer core parameters for the tradeoff between the mantle and outer core in seismic inversions.

VISUAL PRESENTATION

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AUTHOR BIOGRAPHY

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John Rekoske is a graduating senior majoring in Geophysical Engineering and minoring in Data Science. His research with the Department of Geophysics focuses on using high-performance computing to perform numerical simulations of seismic wave propagation from earthquakes to illuminate information about the elastic parameters of the Earth’s interior, especially the outer core. His other research interests involve earthquake hazard modelling, deep learning, and computational seismology.

Sponsored by Phillips 66