A collection of earthquake studies throughout western British Columbia
department or school: Science, Faculty of
department or school: Earth, Ocean and Atmospheric Sciences, Department of
data provider: DSpace
degree campus: UBCV
creator: Littel, Geena
issued: 2024-05-03T08:19:01Z
issued: 2024
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: The tectonic regime of western British Columbia is largely governed by convergence of the offshore oceanic Pacific and Juan de Fuca plates with the continental North American plate. Offshore British Columbia, the Juan de Fuca plate, a remnant of the Farallon plate, subducts beneath Vancouver Island at the Cascadia subduction zone. The Pacific plate obliquely slips along the Queen Charlotte fault, a major translational fault offshore Haida Gwaii extending to southeast Alaska. These zones are joined by the Queen Charlotte triple junction, a tectonically complex region that is rapidly evolving over geologic timescales. Western mainland British Columbia experiences residual transpressional motion from oblique Pacific plate convergence, and volcanic hot spot activity. I use earthquakes to better understand the underlying tectonic processes of these distinct regions, with each presenting its own unique challenges and scientific insights. Offshore, from analysis of a new earthquake catalog I suggest that the triple junction can be modelled as a migrating pull-apart basin under regional transpression. Furthermore, breakup of the Explorer microplate likely occurs as seismicity along a predetermined strength fabric in the crust that was generated during its formation at a spreading ridge. Western British Columbia is generally seismically quiet, save for a unique concentration of earthquakes near the intersection of a major shear zone and a volcanic hot spot trend called the Anahim Volcanic Belt. I investigate these earthquakes by determining accurate hypocenters, focal mechanism solutions, and principal stresses, and by analyzing their spatio-temporal behavior. I interpret them to be a result of reactivated fault strands under northeast-directed extension in weakened lithosphere of the volcanic belt. In the Cascadia subduction zone, I apply an improved detection method to small earthquakes that accompany slow slip along the plate boundary called low-frequency earthquakes. By …
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/88171
note: A collection of earthquake studies throughout westernBritish ColumbiabyGeena LittelB. Sc. Geophysics, University of Oregon, 2018a thesis submitted in partial fulfillmentof the requirements for the degree ofDoctor of Philosophyinthe faculty of graduate and postdoctoral studies(Geophysics)The University of British Columbia(Vancouver)April 2024© Geena Littel, 2024The following individuals certify that they have read, and recommend to the Faculty ofGraduate and Postdoctoral Studies for acceptance, the thesis entitled:A collection of earthquake studies throughout western British Columbiasubmitted by Geena Littel in partial fulfillment of the requirements for the degree ofDoctor of Philosophy in Geophysics.Examining Committee:Michael G. Bostock, Professor, Department of Earth, Ocean, and Atmospheric Sciences,UBCSupervisorCharles G. Sammis, Professor Emeritus, Department of Earth, Ocean, and AtmosphericSciences, UBCSupervisory Committee MemberRon Clowes, Professor Emeritus, Department of Earth, Ocean, and Atmospheric Sciences,UBCUniversity ExaminerCarlos M. Hutt, Assistant Professor, Department of Civil Engineering, UBCUniversity ExaminerEmilie Hooft, Associate Professor & Associate Department Head, Department of EarthSciences, University of OregonExternal ExaminerAdditional Supervisory Committee Members:Catherine L. Johnson, Professor, Department of Earth, Ocean, and Atmospheric Sciences,UBCSupervisory Committee MemberiiAbstractThe tectonic regime of western British Columbia is largely governed by convergence ofthe offshore oceanic Pacific and Juan de Fuca plates with the continental North Ameri-can plate. Offshore British Columbia, the Juan de Fuca plate, a remnant of the Farallonplate, subducts beneath Vancouver Island at the Cascadia subduction zone. The Pacificplate obliquely slips along the Queen Charlotte fault, a major translational fault offshoreHaida Gwaii extending to southeast Alaska. These zones are joined by the Queen Char-lotte triple junction, a tectonicall…
has type: Thesis/Dissertation
date issued: 2024-11
is shown at: 10.14288/1.0442104
language: eng
degree discipline: Geophysics
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Bostock, Michael G.
type: Text
identifier URI: http://hdl.handle.net/2429/88171