[CIG-SHORT] dynamic rupture on realistic mesh

[Brad Aagaard]

Hongfeng,

There are a number of potential differences between planar and nonplanar 
geometry when you setup the problem. As I mentioned before, one of the 
main differences can occur if you resolve a regional stress field onto 
nonplanar geometry. Alternatively, if you explicitly specify shear and 
normal stresses that are independent of fault orientation (e.g., a 
nominal, uniform value), then rupture is much more similar to a planar 
fault-- only the dynamic stress interaction is different.

PyLith doesn't not make any assumptions about the geometry of the fault, 
so the code works exactly the same independent of the fault geometry. 
You should examine your initial conditions and parameters to see 
precisely what the differences are between your planar and nonplanar 
models. You may want to plot the ratio of the shear strain energy to the 
fracture energy (see Steve Day's 1982 paper or Aagaard and Heaton 2008), 
which is related to how easily ruptures propagate for given set of 
conditions (stress field and friction parameters).

Regards,
Brad


On 4/6/12 2:50 PM, Hongfeng Yang wrote:
> I am running dynamic rupture scenarios on a realistic geometry mesh.
> Pylith reads in the initial stress on the fault fine--I can see the
> nucleation zone as I assigned. But in the output, slip on fault is 0,
> indicating the rupture failed to initiate.
>
> I have tried the same parameters on planar faults, one single fault
> plane and kinked fault with multiple planes. In all planar fault cases,
> rupture initiates and propagates.
>
> So it seems to relate to the mesh. Anyone has successful experience of
> running dynamic ruptures using pylith on realistic geometry fault models?
>
> Thanks,
>
> Hongfeng
>
> --
> Postdoctoral Investigator
> Department of Geology and Geophysics
> Woods Hole Oceanographic Institution
> 360 Woods Hole Rd, MS 24
> Woods Hole, MA 02543
>
>
>
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