Earth and Planetary Sciences ETDs

Publication Date

Summer 8-15-2024

Abstract

There are many outstanding questions in plate tectonics that remain unanswered because large regions of the Earth are unexplored, both at the surface and in the subsurface. In this dissertation, I processed and analyzed active source seismic reflection data from the historically understudied Queen Charlotte transform plate boundary. Using this dataset, I found that the southern segment of the plate boundary has active underthrusting, is analogous to subduction zone crustal slivers, and is a site of early subduction initiation. Along the entire plate boundary, I constrained the near-surface thermal gradient using the stability of gas hydrate, finding that it is primarily controlled by the age of the Pacific plate, but fluctuations arise from topography, fluid flow, and surface processes. Analyzing the structure of the Pacific plate offshore Haida Gwaii, I found that flexure of the plate is caused by underthrusting beneath the Queen Charlotte Terrace and significant sedimentation.

Degree Name

Earth and Planetary Sciences

Level of Degree

Doctoral

Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Lindsay L. Worthtington

Second Committee Member

Maureen L. Walton

Third Committee Member

Emily C. Roland

Fourth Committee Member

Brandon Schmandt

Language

English

Keywords

Active Source Seismology, Marine Geophysics, Queen Charlotte Plate Boundary, Transform Plate Boundary, Subduction Initiation

Document Type

Dissertation

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