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Applications: Simulation of EarthquakesEvan Bollig, [email protected]
Summary
Motivation
Earthquake modeling and simulation
Data Assimilation
Computational Requirements
Case Studies
Importance of Earthquake Simulations
Kobe, Japan (1995)
Magnitude 6.9 --> $200B in damage
5,500 Dead; 26,000 Injured
Active prediction program was in place, but not sophisticated enough to give warning
Living on an ACTIVE Earth: Perspectives on Earthquake Science. National Academic Press, Washington D.C. 2003
Things to remember[...] currently no approaches to earthquake forecasting that are uniformly reliable. {SRC p.213}
Events may repeat, but span longer time than documented history and/or larger space than sensor networks can monitor
“Grand Challenges” are just starting
Most “large-scale parallel simulations” are attempts to prove it can be done in parallel
Earthquake models useful in other disciplines (i.e. Tsunami- and Geo-engineers)
Spatial/Temporal Scales{S
RC
p.2
22
}
Scales (Cont.)
Microscopic (~10-6m to 10-1m)
Fault-zone (~10-1m to 102m)
Fault-system (~102m to 104m)
Regional Fault-Network (~104m to 105m)
Tectonic Plate-Boundary (~105m to 107m)
Typical Computational Problems
Data Assimilation
Sensors provide incomplete information to existing simulations
Simulation attempts to forecast possible aftershocks and damage to infrastructures
Example: disloc (NASA JPL)
Earthquake Fault-System Simulations
Particle/slider-block model
Earthquake occurs when cluster of particles displace at same time
Grand Challenges for Earthquakes
Subcommittee on Disaster Reduction (US Government) has 10 year strategy, 6 challenges
Provide hazard and disaster information where and when it is needed
Understand the natural processes that produce hazards
Develop hazard mitigation strategies and technologies
Reduce the vulnerability of infrastructure
Assess disaster resilience
Promote risk-wise behavior
Other Grand Challenge Initiatives
Network for Earthquake Engineering Simulation (NEES)
APEC Cooperation for Earthquake Simulation (ACES)
Australian Computational Earth Systems Simulator (ACcESS)
Network for Earthquake Engineering Simulation (NEES)
NSF Funded “Collaboratory” managing “Grand Challenges” in Geosciences
Share data, software and facilities to encourage collaboration
Provide metadata documenting simulations and events
High Priority Topics:
Performance-based criteria for design, evaluation and retrofit of new/existing structures
Post-disaster safety assessment, repair, loss estimation
Model-based analysis
Example NEES Project
Mitigation of Collapse Risk in Older Concrete Buildings
http://peer.berkeley.edu/grandchallenge/index.html
Hazard assessments in one or more urban regions
Lab and field tests in addition to computational models
January 2007 - December 2012; $3.6M
ACES
Offshoot of APEC (Asia Pacific Economic Cooperation)
APEC Cooperation for Earthquake Simulation
Sponsored by Australia, China, Japan and United States
Goal: develop simulation for the complete earthquake process and provide virtual laboratory to probe behavior
iSERVO Project (ACES)
the international Solid Earth Virtual Research Observatory
http://iservo.edu.au
Started in 2003
Mission: develop web-based services and grid technologies to ensure seamless access to data and models
iSERVO ResultsVirtual California (QUAKESim)
1000 Year simulation
faults divided into 650 segments (10km long, 15km deep)
http://quakesim.jpl.nasa.gov/animations.html
iSERVO ResultsAustralian intraplate model (FEM)
Model interaction bewteen multiple plates
Software Frameworks
OpenSEES (NEES)
Object oriented library for building models, solving problems, etc.
Tcl Model Builder
http://opensees.berkeley.edu/index.php
GeoFEST
2D/3D FEM package written in C
http://www.physics.hmc.edu/GL/geofest/
GeoFEM (used on EarthSimulator)
http://geofem.tokyo.rist.or.jp/
Case Studies: TeraShakeTeraShake 2.1
Mw 7.7 earthquake
230 km section of San Andreas fault
60 second rupture; 250 second simulation
Mesh Dimensions: 3000 x 1500 x 400
contains 1.8 billion cubes (200m resolution)
Computing Requirements
18,000 CPU hrs
240 processors of the 10 teraflop IBM DataStar supercomputer at SDSC
47 TB of data produced (150,000 files)
http://www.hpcwire.com/hpcwire/hpcwireWWW/04/1217/108981.htmlhttp://epicenter.usc.edu/cmeportal/TeraShake.html
See What’s Shaking (IEEE Vis 2006)
Contest to visualize subset of TeraShake 2.1 data
Motivate new techniques and software for seismic visualization
See What’s Shaking (IEEE Vis 2006)
Contest to visualize subset of TeraShake 2.1 data
Motivate new techniques and software for seismic visualization http://2006_ieee_vis.sdsc.edu/2006_ieee_vis_data/submissions/
22122/terashake1.png
See What’s Shaking (IEEE Vis 2006)
Contest to visualize subset of TeraShake 2.1 data
Motivate new techniques and software for seismic visualization http://2006_ieee_vis.sdsc.edu/2006_ieee_vis_data/submissions/
87788/Image%202.png
See What’s Shaking (IEEE Vis 2006)
Contest to visualize subset of TeraShake 2.1 data
Motivate new techniques and software for seismic visualization
Bollig, Womeldorff, Chen (2008)
Case Study: Tsunami Simulation
December 26, 2004
Mw 9.3 event
produced waves up to 25m (80ft) tall
New Jersey water level fluctuated 34cm
300,000 people killed
Case Study: Tsunami Simulation
December 26, 2004
Mw 9.3 event
produced waves up to 25m (80ft) tall
New Jersey water level fluctuated 34cm
300,000 people killed
Court
esy o
f E
arth
Obse
rvat
ory
and N
AS
A G
SF
C
Tsunami ModelFinite Element Method
more than 2 million nodes
Mesh generated from GTOPO30 (http://
edc.usgs.gov/products/elevation/gtopo30/gtopo30.html)
global elevation model with grid spacing of 30 arc seconds (1 km)
Huai Zhang, Yaolin Shi, Dave A. Yuen, Ying-chun Liu, Chaofan
Zhang and Xiaoru Yuan, "Modelling and Visualization of Tsunamis"
Submitted to Pure and Applied Geophysics (PAGEOPH). Birkhauser
Verlag AG. (In Press).
Tsunami ModelFinite Element Method
more than 2 million nodes
Mesh generated from GTOPO30 (http://
edc.usgs.gov/products/elevation/gtopo30/gtopo30.html)
global elevation model with grid spacing of 30 arc seconds (1 km)
Huai Zhang, Yaolin Shi, Dave A. Yuen, Ying-chun Liu, Chaofan
Zhang and Xiaoru Yuan, "Modelling and Visualization of Tsunamis"
Submitted to Pure and Applied Geophysics (PAGEOPH). Birkhauser
Verlag AG. (In Press).
Case Studies: Tsunami SimulationProbabilistic model for forecasting hazards
Scenario with inter-plate thrust along Manila subduction zone in South China Sea
Mw 7.5 event southwest of Philippines
Furthest from Chinese mainland
Yingchun Liu, Angela Santos, Shuo M. Wang, Yaolin Shi, Hailing Liu, and David A. Yuen.
Tsunami Hazards From Potential Earthquakes along South China Coast. Physics of the
Earth and Planetary Interiors (PEPI). Elsevier, 2007, Vol.163, 233–245. (SCI)
Creative Expression
Results overlayed in Google Earth (interactive)
Carefully chosen colormaps help isolate areas at high risk of damage
Xiaoru Yuan, Yingchun Liu, Baoquan Chen, David A. Yuen and Tomas
Pergler. “Visualization of High Dynamic Range Data in Geosciences”
Physics of the Earth and Planetary Interiors (PEPI), 163:312-320, 2007.
Elsevier. DOI
Acknowledgements
Thanks to Yuen’s Group (Univ. of MN Twin Cities) for Tsunami images