Abstract
Stochastic slip rupture modeling is a computationally efficient
reduced-physics approximation that has the capability to create any
number of unique ruptures based only on a few statistical assumptions.
Its simplicity and efficiency make it an attractive and viable option
for testing early warning systems, hazard assessments, and
infrastructure response studies. Yet a fundamental question pertaining
to this approach is whether the slip distributions calculated in this
way are “realistic”. More specifically, can stochastic modeling
reproduce slip distributions that match what is seen in M9+ events
recorded in instrumental time? Here, we start with the 2011 M9.1
Tohoku-oki earthquake and tsunami where we test both a stochastic method
with a homogeneous background mean model and a method where slip is
informed by an additional interseismic coupling constraint. We test two
coupling constraints with varying assumptions of either trench-locking
or -creeping and assess their influence on the calculated ruptures. We
quantify the dissimilarity of slip distribution between the 12,000
modeled ruptures and a slip inversion for the Tohoku earthquake. We also
model tsunami inundation for over 300 ruptures and compare the results
to an inundation survey along the eastern coastline of Japan. We
conclude that stochastic slip modeling can produce ruptures that can be
considered “Tohoku-like”, and inclusion of coupling can both
positively and negatively influence the ability to create realistic
ruptures. We then expand our study and show that for the 1960 M9.4-9.6
Chile and 2004 M9.1-9.3 Sumatra events, stochastic slip modeling has the
capability to produce realistic ruptures.