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Tsunamis and splay fault dynamics
Author(s) -
Wendt James,
Oglesby David D.,
Geist Eric L.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl038295
Subject(s) - geology , fault (geology) , thrust , seismology , homogeneous , boundary (topology) , thrust fault , earthquake rupture , finite element method , deformation (meteorology) , boundary value problem , tsunami earthquake , structural engineering , aerospace engineering , physics , engineering , mathematical analysis , oceanography , mathematics , quantum mechanics , thermodynamics
The geometry of a fault system can have significant effects on tsunami generation, but most tsunami models to date have not investigated the dynamic processes that determine which path rupture will take in a complex fault system. To gain insight into this problem, we use the 3D finite element method to model the dynamics of a plate boundary/splay fault system. We use the resulting ground deformation as a time‐dependent boundary condition for a 2D shallow‐water hydrodynamic tsunami calculation. We find that if the stress distribution is homogeneous, rupture remains on the plate boundary thrust. When a barrier is introduced along the strike of the plate boundary thrust, rupture propagates to the splay faults, and produces a significantly larger tsunami than in the homogeneous case. The results have implications for the dynamics of megathrust earthquakes, and also suggest that dynamic earthquake modeling may be a useful tool in tsunami research.