1. VISUALIZING EARTHQUAKE SIMULATION DATA Amit Chourasia 1, Steve Cutchin 1, Alex DeCastro 1, Geoffrey Ely 2 1 San Diego Supercomputer Center 2 Scripps Institute of Oceanography University of California, San Diego Presented By: Amit Chourasia, Visualization Scientist, SDSC Presented to: Virtual Globes Session AGU Fall meeting, San Francisco, Dec 13 th 2007

2. TeraShake Simulation Region  600km x 300km x 80km  Spatial resolution = 200m  Mesh Dimensions 3000 x 1500 x 400 = 1.8 billion mesh points  Simulated time = 4 minutes  Number of time steps = 22,728 (0.011 sec time step)  60 sec source duration from Denali  3D Crustal structure: subset of SCEC CVM3.0  Near-surface S-wave velocity truncated at 500m/s, up to 0.5 Hz

3. Data  Domain Resolution: 3000x1500x400 uniform  3 scalar fields (2D and 3D, floating point)  Derived data (magnitudes, vorticity, etc)  Temporal (22727 steps)  Size 10-50TB per simulation (potentially 430 TB)  Input characteristics (volumetric stiffness, etc)

4. General Questions & Problems  Regions of impact  Occurrence of peak velocities and there location  Understand wave propagation  How to verify and validate ?  How to analyze and gain scientific insight ?  How to share information among experts and others ?

5. Viz Design Evolution 5

6. Movie

7. Maps 7 TeraShake1.3: Spectral Acceleration at 3.0 sec

8. Self Contouring Technique 8 TeraShake1.3: Spectral Acceleration at 3.0 sec

9. Geo Context Simple Overlays  City names  Faultlines  Major Freeways Not sufficient Customized color mapping Broader information overlays (minor roads, POI’s,…..) Interactivity

10. Context Population (2000 Census) Road Rail Hospital Harbor.

11. Map service portal 11 Live Demo

12. Pre-cooked Demo  Map Service Movie Map Service Movie  Google Earth Integration Movie Google Earth Integration Movie

13. Pipeline Web Browser Colormap Applet Server Back End Data Fetch Reformat data WGS84 Colormap original data Colormap transformed data Request Publish Execution Colormaping: SVT, TEEM

14. Software  Scalable Visualization Toolkit* (batch volume rendering)  Deskvox, Meshviewer (interactive volume rendering)  Storage Resource Broker* (SRB)  Teem toolkit *  Google Earth * TeraGrid friendly

15. Lessons Learned (TeraShake)  In the north-westward propagating rupture scenario the wave propagation is strongly guided toward the Los Angeles basin after leaving the San Andreas Fault (unexpected)  The sediment filled basin acts as an amplification source for trapped waves. A Strong amplification is observed in the LA basin long after the initial rupture (unexpected)  Contiguous basins act as energy channels, enhancing ground motion in parts of the San Gabriel and Los Angeles basins.  Identification of regions of particularly strong shaking  Validation of input rupture model and instability identification  Observation of star burst patterns in the Spectral Amplification maps (unexpected) Over 130,0000 images, Consumed 40,000 hrs of compute time, More than 50 unique animations 15

16. Future Work  Find/develop  novel techniques to visually represent data  Methods to measure and quantify errors  Effective visualization tools and services  Temporal animations methods  Make visualizations accessible

17. References  Visual Insights into High-Resolution Earthquake Simulations. IEEE Computer Graphics and Applications,vol. 27, no. 5, pp. 28-34, September/October, 2007  Enabling very-large scale earthquake simulations on parallel machines. "Advancing Science and Society through Computation", International Conference on Computational Science 2007, Part I, Lecture Notes in Computer Science series 4487, pp. 46-53, Springer  Strong shaking in Los Angeles expected from southern San Andreas earthquake, Geophys. Res. Lett. 33, L07305,doi:10.1029/2005GRL025472

18. Acknowledgements Contributors Natalie Rubin, Lucas Gilbert, John Moreland Scientists Kim Olsen, Steve Day, Bernard Minster, Tom Jordan, Phil Maechling, Yifeng Cui, Reagan Moore  Southern California Earthquake Center (SCEC)  San Diego Supercomputer Center (SDSC) Funding National Science Foundation

19. Thanks for your Patience ?- Webpage: http://visservices.sdsc.edu/scechttp://visservices.sdsc.edu/scec Email: amit # sdsc.edu