16/9/2011ucerf3 / eq simulators workshop rsqsim jim dieterich keith richards-dinger uc riverside...
TRANSCRIPT
![Page 1: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/1.jpg)
1 6/9/2011 UCERF3 / EQ Simulators Workshop
RSQSim
Jim DieterichKeith Richards-Dinger
UC Riverside
Funding: USGS NEHRPSCEC
![Page 2: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/2.jpg)
2 6/9/2011 UCERF3 / EQ Simulators Workshop
Representation of Fault Friction• Constitutive relation:
• State evolution:
• Stress evolution:
• Terms in red are additional ones due to normal stress variations (Linker and Dieterich, 1992)
• Interaction coefficients, K, calculated from the dislocation solutions of Okada, 1992
• Tectonic stressing rates derived from backslipping the model
• Numerical integration too slow for the scale of problems we would like to address
![Page 3: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/3.jpg)
3 6/9/2011 UCERF3 / EQ Simulators Workshop
Representation of Fault Friction• Constitutive relation:
• State evolution:
• Stress evolution:
State 1: nucleation State 0: locked fault
State 2: seismic slip
![Page 4: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/4.jpg)
4 6/9/2011 UCERF3 / EQ Simulators Workshop
Representation of Fault Friction• No predetermined failure stress or stress drop• Stress drop scales roughly as
![Page 5: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/5.jpg)
5 6/9/2011 UCERF3 / EQ Simulators Workshop
Representation of Fault Friction• No predetermined failure stress or stress drop• Stress drop scales roughly as
![Page 6: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/6.jpg)
6 6/9/2011 UCERF3 / EQ Simulators Workshop
Approximations to Elastodynamics
Parameters that influence the rupture process:• Slip speed during coseismic slip determined from
shear impedance considerations• Reduction of a on patches nearby to seismically
slipping patches• Stress overshoot during ruptures
![Page 7: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/7.jpg)
7 6/9/2011 UCERF3 / EQ Simulators Workshop
Effect of Overshoot on Rupture Characteristics
Large overshoot (13%)
Small overshoot (1%)
![Page 8: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/8.jpg)
8 6/9/2011 UCERF3 / EQ Simulators Workshop
Approximations to Elastodynamics Values for rupture parameters determined by comparison with fully dynamic rupture models
DYNA3D – Fully dynamic finite element simulation
RSQsim – Fast simulation
Propagation time 14.0 s
Propagation time 14.3 s
![Page 9: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/9.jpg)
9 6/9/2011 UCERF3 / EQ Simulators Workshop
Smooth Initial Stress (w/ block of higher normal stress)
![Page 10: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/10.jpg)
10 6/9/2011 UCERF3 / EQ Simulators Workshop
• Rate-strengthening (a > b) patches– Approximated as always sliding at steady-state– Distributed as
• Deep creeping extensions to major faults• Shallow creep on major faults• Entire creeping sections (e.g. SAF north of Parkfield)
– Possibly with small imbedded stick-slip patches
• More complicated mixed stick-slip and creeping areas (e.g. Hayward Fault)
![Page 11: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/11.jpg)
11 6/9/2011 UCERF3 / EQ Simulators Workshop
Penetration of slip of large events into creeping zone
![Page 12: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/12.jpg)
12 6/9/2011 UCERF3 / EQ Simulators Workshop
Fraction of moment release in creeping section
Aftershocks
![Page 13: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/13.jpg)
13 6/9/2011 UCERF3 / EQ Simulators Workshop
1989 Loma Prieta EarthquakeSimulation
Omori's law R t 1
Omori's law R t 1
Small repeating earthquakes
![Page 14: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/14.jpg)
14 6/9/2011 UCERF3 / EQ Simulators Workshop
Power-law temporal clustering
Decay of aftershocks follows Omori power law t -p with p = 0.77
Foreshocks (not shown) follow an inverse Omori decay with p = 0.92
Dieterich and Richards-Dinger, PAGEOPH, 2010
Stacked rate of seismicity relative to mainshock origin time
![Page 15: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/15.jpg)
15 6/9/2011 UCERF3 / EQ Simulators Workshop
Power-law temporal clustering
Interevent Waiting Time DistributionsCalifornia Catalog 1911 – 2010.5
![Page 16: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/16.jpg)
16 6/9/2011 UCERF3 / EQ Simulators Workshop
Power-law temporal clustering
Space – Time Distributions
![Page 17: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/17.jpg)
17 6/9/2011 UCERF3 / EQ Simulators Workshop
Earthquake cluster along San Andreas Fault
M7.3 43 aftershocks in 18.2days
All-Cal model – SCEC Simulator Comparison Project
![Page 18: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/18.jpg)
18 6/9/2011 UCERF3 / EQ Simulators Workshop
Earthquake cluster along San Andreas Fault
M6.9 Followed by 6 aftershocks in 4.8 minutes
All-Cal model – SCEC Simulator Comparison Project
![Page 19: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/19.jpg)
19 6/9/2011 UCERF3 / EQ Simulators Workshop
Earthquake cluster along San Andreas Fault
M7.2
All-Cal model – SCEC Simulator Comparison Project
![Page 20: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/20.jpg)
20 6/9/2011 UCERF3 / EQ Simulators Workshop
• slip ~2.3 - 4.0 cm
• duration ~10-40 days
• inter-event time - ~10-19 months
• simultaneous slip in different areas
• no Omori clustering
• spontaneous segmentation
Colella et al.,submitted
Colella et al.,submitted
Slow-slip events
![Page 21: 16/9/2011UCERF3 / EQ Simulators Workshop RSQSim Jim Dieterich Keith Richards-Dinger UC Riverside Funding: USGS NEHRP SCEC](https://reader036.vdocuments.us/reader036/viewer/2022062322/56649ce35503460f949af556/html5/thumbnails/21.jpg)
21 6/9/2011 UCERF3 / EQ Simulators Workshop
Summary or Conclusions (if appropriate or desired)