Morphologic Expression of Shallow Volcanics and Ice Sheet Extent Along the Queen Charlotte Fault, Se Alaska and British Columbia
Description:
Transform faults represent one of the three types of major plate boundaries on Earth and are the least associated with volcanism. The Queen Charlotte fault (QCF) is the fastest-slipping ocean-continent transform fault in the world at 50-57 mm/yr (Brothers et al., 2020). It hugs the continental slope along western North America for >900 km between southern B.C. and southeast Alaska, roughly coincident with the location of the western extent of the Cordilleran ice sheet (CIS) during multiple Pleistocene glaciations. Young (Quaternary) volcanic features exist within 25 km on both sides of the fault, but the mechanisms driving this volcanism remain uncertain. Coupled with recent fault trace mapping and lithospheric-scale geophysical imaging of the plate boundary from the Transform Obliquity along the Queen Charlotte and Earthquake Study (TOQUES) experiment, we explore how the distribution of volcanism relative to fault structural variations and former ice sheet limits may provide new insight into the timing and mechanisms of volcanic activity in southeast Alaska and British Columbia. Using previously published and legacy seafloor geophysical data, as well as new multibeam bathymetry and sub-bottom profile data along the QCF, we synthesize diverse evidence for young and active volcanic features along the QCF. We also reassess seafloor morphology for evidence of the extent of the CIS relative to the location of the plate boundary and currently active fault trace. Mapping the distribution of volcanic activity along the QCF will provide a more robust explanation of ‘leaky transform’ magmatism at conservative boundaries like transform faults.
Session: Structure, Seismicity and Dynamics of the Queen Charlotte-Fairweather Fault System [Poster Session]
Type: Poster
Date: 5/1/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Katie
Student Presenter: Yes
Invited Presentation:
Authors
Katie Kennedy Presenting Author Corresponding Author ktmaekennedy@gmail.com Western Washington University |
Emily Roland rolande2@wwu.edu Western Washington University |
Doug Clark dhclark@wwu.edu Western Washington University |
Lindsay Worthington lworthington@unm.edu University of New Mexico |
Jim Baichtal baichtal557@gmail.com n/a |
Gary Greene greene@mlml.calstate.edu California State |
Maureen Walton Maureen.Walton@nrlssc.navy.mil U.S. Naval Research Laboratory |
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Morphologic Expression of Shallow Volcanics and Ice Sheet Extent Along the Queen Charlotte Fault, Se Alaska and British Columbia
Category
Structure, Seismicity and Dynamics of the Queen Charlotte-Fairweather Fault System