Earth and Planetary Sciences ETDs

Publication Date

Summer 8-1-2023

Abstract

This study investigates whether the Yellowstone Caldera has enough melt to mute S-waves, creating a seismic shadow zone. Using a dense nodal deployment of ~650 stations, 7-9 earthquakes during the nodal deployment, and 21 broadband stations with 3,000-4,000 events per station; amplitude and noise maps, seismograms, and automatic phase picks probabilities from a deep learning model were analyzed to assess the potential role of melt, crustal attenuation, and noise in affecting body waves, particularly S-phases. The results are inconclusive, with unclear evidence whether observed amplitude decay is normal signal decay due to distance, noise-related, melt, or from scattering and intrinsic attenuation. The probability maps show no clear difference in performance between P and S-phases, suggesting other factors such as noise or scattering may be involved. These observations suggest the need for continued research and understanding of scattering and intrinsic attenuation in the upper crust. The long-term deployment of permanent broadband stations in Yellowstone could support future work in calculating attenuation and discriminating between scattering and intrinsic attenuation.

Degree Name

Earth and Planetary Sciences

Level of Degree

Masters

Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Brandon Schmandt

Second Committee Member

Lindsay Lowe Worthington

Third Committee Member

Tobias Fischer

Language

English

Keywords

Yellowstone, seismology, caldera, magma reservoir, geophysics, shadow zone

Document Type

Thesis

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