Sarah Minson Caltech February 22, 2011LLNL. Mark Simons (Caltech) James Beck (Caltech)
Sarah Minson California Institute of Technology
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Transcript of Sarah Minson California Institute of Technology
Potential of real- time high-rate scientific, consumer, and crowd- sourced GPS for earthquake early warning and rapid response
Sarah MinsonCalifornia Institute of Technology
Real-time finite fault slip models for earthquake early warning
Sarah E. MinsonCalifornia Institute of Technology
Jessica R. Murray, John O. Langbein, Joan S. GombergU.S. Geological Survey
What happens after an earthquake?Real-time:
EEWLocationMw
Shortly thereafter:Network response
Better locationBetter MwSource mechanism
Much, much later:Research/source studies
Fault geometryFinite fault slip modelKinematic rupture model
Why not just do this in real-time?
Moment saturation
0 20 40 60 80 100 120 1404
5
6
7
8
9
Tohoku EEW
Time (sec)
Mag
nitu
de
Mw 9.0
Final
Gavin Hayes and David Wald
Let’s Play a Math TrickUse Bayesian inference with a conjugate prior to derive:1. Analytical expression for PDF describing all
possible slip distributions2. Analytical expression for the probability
associated with any fault geometry
Inversion DesignAssume an epicenter location from seismic EEWConsider the set of faults centered at the epicenter with any strike and dip
Build discretized fault with total extent large enough to encompass rupture Only include offsets from stations within expected P-wave range
No moment saturation with GPS
Seismic EEW
GPS
PTWC
True Mw Evolution
Tsunami early warningBest Slip Model Real-time Uniform
Seaflooruplift
Faultslip
ConclusionsReal-time finite fault source models require only existing information:
EEW locationReal-time high-rate GPS streams
These models are not limited by computational expense. They are limited by the time it takes for the rupture to grow in size and information about the rupture to propagate
Take-Home MessageFor regions with both dense seismic networks and real-time high-rate GPS, we could have non-saturating magnitudes and finite fault slip distributions (and thus accurate warnings and shaking forecasts) in real-time starting today.