Earth and Planetary Sciences ETDs

Publication Date

Fall 11-14-2022

Abstract

Imaging Earth’s crust is critical to understanding processes in the near-surface that affect civilization such as the interaction of seismic waves with the near-surface to generate natural or man-made hazards or investigating how the shallow crust affects the distribution of resources. In chapter 1, I processed and analyzed active source seismic data recorded by ~1000 geophones that were acquired over the legacy HADDOCK nuclear test at the Nevada National Security Site. Using seismic reflection and refraction methods, we image the partially collapsed post-detonation structure to better understand the velocity structure in and around the HADDOCK chimney. Results from this work can be generalized to assist in the investigation of suspected Underground Nuclear Explosions and support ongoing source physics experiments at the Nevada National Security Site. In chapter 2, I investigate the subduction zone interface structure beneath Kodiak Island in Alaska. I estimate P-to-S receiver functions from distant earthquakes recorded by ~400 three-component 5 Hz geophones. We determined that the 1964 Great Alaska Earthquake ruptured beyond the extent of the low-velocity shear zone observed in the Kenai Peninsula. In chapter 3, I study the subsurface structure of the Raton Basin in New Mexico. I analyze teleseismic waveforms recorded by nine broadband and 96 5 Hz geophones deployed at different times within the last fourteen years. Results from this work show that the top of the Early Cretaceous-age Dakota Formation is the most prominent seismic boundary basin-wide. The results also suggest that local earthquakes attributed to reactivated basement faults occur from roughly the sediment-basement boundary and extend deeper into the Precambrian basement. The three chapters presented here were prepared as manuscripts to be submitted for publication in peer-reviewed Earth Sciences journals. Chapter 1 is modified from a manuscript that was published in the Bulletin of the Seismological Society of America, 2021, Volume 111. Chapter 2 was published in Geophysical Research Letters, 2022, Volume 49. A version of Chapter 3 will be submitted to a peer-reviewed journal. Together these works create high-resolution images of the near-surface environment to better understand both man-made and natural geologic structures.

Degree Name

Earth and Planetary Sciences

Level of Degree

Doctoral

Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Lindsay L. Worthington

Second Committee Member

Brandon Schmandt

Third Committee Member

Robert E. Abbott

Fourth Committee Member

Susan L. Bilek

Language

English

Keywords

Receiver functions, seismic reflection, 1964 Great Alaska Earthquake, underground nuclear test, Nevada National Security Site, Underground nuclear explosion, subduction zone interface, Raton Basin, teleseismic earthquakes

Document Type

Dissertation

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