Geometrical effects of a subducted seamount on stopping megathrust ruptures
MetadataShow full item record
We have numerically simulated dynamic ruptures along a “slip-weakening” megathrust fault with a subducted seamount of realistic geometry, demonstrating that seamounts can act as a barrier to earthquake ruptures. Such barrier effect is calculated to be stronger for increased seamount normal stress relative to the ambient level, for larger seamount height-to-width ratio, and for shorter seamount-to-nucleation distance. As the seamount height increases from 0 to 40% of its basal width, the required increase in the effective normal stress on the seamount to stop ruptures drops by as much as ~20%. We further demonstrate that when a seamount is subducted adjacent to the earthquake nucleation zone, coseismic ruptures can be stopped even if the seamount has a lower effective normal stress than the ambient level. These results indicate that subducted seamounts may stop earthquake ruptures for a wide range of seamount normal stress conditions, including the case of the thrust fault being lubricated by seamount-top fluid-rich sediments, as suggested from observations in the Japan and Sunda Trenches.
Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 40 (2013): 2011–2016, doi:10.1002/grl.50509.
Suggested CitationGeophysical Research Letters 40 (2013): 2011–2016
Showing items related by title, author, creator and subject.
Yang, Hongfeng; Liu, Yajing; Lin, Jian (American Geophysical Union, 2012-12-19)Subducted seamounts have been linked to interplate earthquakes, but their specific effects on earthquake mechanism remain controversial. A key question is under what conditions a subducted seamount will generate or stop ...
Llenos, Andrea L. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-06)Large earthquake rupture and triggering mechanisms that drive seismicity in subduction zones are investigated in this thesis using a combination of earthquake observations, statistical and physical modeling. A comparison ...
Numerical simulations on megathrust rupture stabilized under strong dilatancy strengthening in slow slip region Liu, Yajing (John Wiley & Sons, 2013-04-15)Episodic slow slip events (SSEs) typically involve a few millimeters to centimeters of slip over several days to months at depths near or further downdip of megathrust seismogenic zones. Despite its widespread presence in ...