Deformation of the Pacific Plate west of the Queen Charlotte Fault

Perrin, Robert

Deformation of the Pacific Plate west of the Queen Charlotte Fault

dc.contributor.advisor	Lauer, Rachel
dc.contributor.author	Perrin, Robert
dc.contributor.committeemember	Karchewski, Brandon
dc.contributor.committeemember	Pidlisecky, Adam
dc.contributor.committeemember	Tutolo, Benjamin
dc.contributor.committeemember	Innanen, Kristopher
dc.contributor.committeemember	Schaeffer, Andrew
dc.date	2024-05
dc.date.accessioned	2024-04-15T17:29:57Z
dc.date.available	2024-04-15T17:29:57Z
dc.date.issued	2024-03-26
dc.description.abstract	The Queen Charlotte Fault (QCF) is a transform fault that stretches from Haida Gwaii to Icy Point, Alaska, and has been of particular interest since an earthquake in 2012 demonstrated its geohazard potential. Observations made along the margin since then have raised questions about how deformation is distributed around the fault. Firstly, plate motion along the QCF is aligned with the fault apart from its southern section, where there is slight convergence between the Pacific and North American plates. While some evidence suggests the convergence may be accommodated by thickening of the Pacific Plate, there are uncertainties about how this is distributed along the QCF. Secondly, along the southern QCF lies the Queen Charlotte Terrace and several oblique faults. These features extend approximately 30 km west of the fault and are thought to be part of the mechanism that accommodates transpression along the southern QCF. This raises questions about why they are limited to this distance, and what the zone of influence of the fault might be. Finally, deformation of the Pacific Plate is controlled by lithospheric strength, which is a function of both thickness and temperature. Thick sediments west of the QCF, should allow young crust to be warmer than areas that are lightly sedimented. The limited heat flow observations that exist along the QCF, however, show a heat flow deficit, suggesting the crust may be cooler than expected. This raises questions about the thermal state of the crust, and how that may impact crustal deformation. This study examines these observations using several existing geophysical datasets. This study shows that the crust appears to be thicker than typical oceanic crust along Haida Gwaii. I also show that the zone of influence of the QCF is related to the dominant geometrical wavelengths of the fault and is consistent with observed deformation. Finally, I examine the thermal state of the crust to show that crustal cooling by hydrothermal circulation is likely occurring. The conclusions from this study improve our understanding of deformation of the Pacific Plate and underscore the need for continued studies along the QCF.
dc.identifier.citation	Perrin, R. (2024). Deformation of the Pacific Plate west of the Queen Charlotte Fault (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	https://hdl.handle.net/1880/118411
dc.language.iso	en
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	Queen Charlotte Fault
dc.subject	Heat flow
dc.subject	Gravity
dc.subject	Strike-slip fault
dc.subject	stress perturbation
dc.subject	Crustal deformation
dc.subject.classification	Geophysics
dc.subject.classification	Geology
dc.title	Deformation of the Pacific Plate west of the Queen Charlotte Fault
dc.type	doctoral thesis
thesis.degree.discipline	Geoscience
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.thesis.accesssetbystudent	I do not require a thesis withhold – my thesis will have open access and can be viewed and downloaded publicly as soon as possible.