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TitleDo subducting seamounts generate or stop large earthquakes?
AuthorWang, K; Bilek, S L
SourceGeology vol. 39, no. 9, 2011 p. 819-822,
Alt SeriesEarth Sciences Sector, Contribution Series 20100497
Mediapaper; on-line; digital
File formatpdf
Subjectstectonics; structural geology; geophysics; crustal movements; crustal studies; subduction; subduction zones; tectonic setting; tectonic environments; tectonic zones; earthquakes; earthquake studies; earthquake risk; earthquake mechanisms; seismicity
Illustrationslocation maps
ProgramTargeted Hazard Assessments in Western Canada, Public Safety Geoscience
AbstractSeamount subduction is a common process in subduction zone tectonics. Contradicting a widely held expectation that subducting seamounts generate large earthquakes, seamounts subduct largely aseismically, producing numerous small earthquakes. On rare occasions when they do produce relatively large events, the ruptures tend to be complex, suggesting multiple rupture patches or faults. We explain that the seismogenic behavior of these seamounts is controlled by the development and evolution of an adjacent fracture network during subduction and cannot be described using the frictional behavior of a single fault. The complex structure and heterogeneous stresses of this network provide a favorable condition for aseismic creep and small earthquakes but an unfavorable condition for the generation and propagation of large ruptures.