Numerical simulations on megathrust rupture stabilized under strong dilatancy strengthening in slow slip region
MetadataShow full item record
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 subduction margins, it remains unknown how SSEs interact with the seismogenic zone and affect megathrust ruptures. Here, I construct a 2-D thrust fault model governed by rate-state friction to investigate how fault dilatancy influences the amplitude and spatial distribution of‘ coseismic slip, afterslip, and SSEs. Model results illustrate that, under strong dilatancy and high pore pressure around the friction stability transition, coseismic rupture stops at the onset of SSEs. Modeled SSEs have lower velocities, longer recurrence intervals and durations, and larger slip amounts as dilatancy becomes stronger, demonstrating a transition from short-term to long-term type of SSE behavior. These results qualitatively explain the range of spatial distributions of SSEs and megathrust ruptures observed or inferred in natural subduction zones. Furthermore, the relative depths of SSEs and megathrust afterslip may serve as an indicator of dilatancy effectiveness.
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): 1311–1316, doi:10.1002/grl.50298.
Showing items related by title, author, creator and subject.
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 ...
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 ...
Heterogeneous rupture in the great Cascadia earthquake of 1700 inferred from coastal subsidence estimates Wang, Pei-Ling; Engelhart, Simon E.; Wang, Kelin; Hawkes, Andrea D.; Horton, Benjamin P.; Nelson, Alan R.; Witter, Robert C. (John Wiley & Sons, 2013-05-15)Past earthquake rupture models used to explain paleoseismic estimates of coastal subsidence during the great A.D. 1700 Cascadia earthquake have assumed a uniform slip distribution along the megathrust. Here we infer ...