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TitleInterplate earthquakes as a driver of shallow subduction erosion
AuthorWang, K; Hu, Y; von Huene, R; Kukowski, N
SourceGeology vol. 38, no. 5, 2010 p. 431-434, (Open Access)
Alt SeriesEarth Sciences Sector, Contribution Series 20090309
Mediapaper; on-line; digital
File formatpdf
Subjectstectonics; geophysics; earthquakes; earthquake mechanisms; subduction; subduction zones; plate motions; plate margins; erosion; stress analyses
Illustrationsschematic representations
ProgramTargeted Hazard Assessments in Western Canada, Public Safety Geoscience
Released2010 05 01
AbstractBasal erosion is a prevalent process at subduction zones and plays an important role in the mass balance of global plate tectonics. In contradiction with the theoretical expectation that basal erosion requires high basal friction and hence compression in the upper plate, extensional faulting is commonly observed in submarine wedges that undergo such erosion. Here we propose a model to explain this apparent paradox in terms of stress fl uctuations during earthquake cycles. In this model, basal erosion occurs during large earthquakes when the shallow, rate-strengthening part of the plate interface strengthens and its overlying wedge weakens, but extension occurs during interseismic relaxation of wedge stress. The mechanics of basal erosion provide important information on the nature of the updip limit of the megathrust seismogenic zone in margins dominated by basal erosion.