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TitleThe Queen Charlotte Fault, British Columbia: seafloor anatomy of a transform fault and its influence on sediment processes
AuthorBarrie, J V; Conway, K W; Harris, P T
SourceGeo-Marine Letters vol. 33, no. 4, 2013 p. 311-318,
Alt SeriesEarth Sciences Sector, Contribution Series 20120465
Mediaon-line; digital; paper
File formatpdf
ProvinceBritish Columbia; Offshore region
NTS103B; 103C/16; 103F; 103G/04; 103J/04; 103K/01; 103K/02; 103K/03; 103K/04
AreaHaida Gawaii; Queen Charlotte Islands
Lat/Long WENS-133.0000 -132.0000 53.2500 52.7500
Subjectsmarine geology; structural geology; geophysics; structural features; seafloor topography; faults; faults, transform; bathymetry; Queen Charlotte Fault
Illustrationslocation maps; photographs; plots
ProgramMarine Geohazards, Public Safety Geoscience
Released2013 06 09
AbstractThe Queen Charlotte Fault Zone (QCFZ) off western Canada is the northern equivalent to the San Andreas Fault Zone, the Pacific - North American plate boundary. Geomorphologic expression and surface processes associated with the QCFZ system have been revealed in unprecedented detail by recent seabed mapping surveys. Convergence of the Pacific and North American plates along northern British Columbia is well known, but how the QCFZ accommodates this convergence is still a subject of controversy. The multibeam sonar bathymetry data reveal, for the first time, evidence of a fault valley with small depressions on the upper slope, offshore central Haida Gwaii (Queen Charlotte Islands). The depressions form where strike-slip right-step offsets have realigned the fault due to oblique convergence. Core stratigraphy and radiocarbon dating of sediments within the fault valley and small depressions suggest that these features are recent in origin. In addition, the development of the fault valley and dislocation of submarine canyons control sediment migration from the continental shelf through to the lower slope. This interpretation of the geomorphic expression of major plate tectonic processes along the QCFZ can now be tested with new surveys subsequent to the October 2012 magnitude 7.7 earthquake.
Summary(Plain Language Summary, not published)
The Queen Charlotte Fault off Haida Gwaii, British Columbia is the continuation of the earthquake zone extending from California to Alaska. Visual expression of the fault along the seafloor has been revealed in unprecedented detail by recent seabed mapping surveys. The fault lies in a small valley with occasional small depressions, or pond like features, breaking the continuous trace. Each time there is a small depression the fault shifts slightly to the east. The fault also cuts submarine canyons that extend westward from the coast of Haida Gwaii into the depths of Pacific Ocean, so that the canyon is displaced north-south, and in some cases, downward steps form along the axis of the canyons when they cross the fault.