COMPLEXITY IN A SPATIALLY UNIFORM CONTINUUM FAULT MODEL
SHAW BE
GEOPHYSICAL RESEARCH LETTERS
21: (18) 1983-1986 SEP 1 1994
Abstract:
Recently, Rice [1993] pointed out that, up to now, the
self-organizing models which have produced complex nonperiodic sequences
of events have all been sensitive to the spatial discretization used, and
thus did not have a well defined continuum limit. He went on the suggest
that spatial nonuniformity or ''inherent discreteness'' may be a necessary
ingredient in allowing the complexity to develop in these systems. In this
paper, I present a counterexample to this suggestion: a spatially uniform
model with a well defined continuum limit is shown to give rise to complex
nonperiodic sequences. The complexity arises in the deterministic model
from inertial dynamics with a velocity-weakening frictional instability,
with the instability being stabilized at short lengthscales by a viscous
term. The numerical results are shown to be independent of the spatial
discretization for discretizations small compared to the viscous lengthscale.
Furthermore, the qualitative features of the complexity produced are seen
to be invariant with respect to two very different types of small scale
cutoffs, implying a universality of the results with respect to the details
of the small scale cutoff.