Press Archive

SDSC Helps National Geographic Explore the 'Big One'

SDSC Visualizations Featured in National Geographic Explorer Program, "LA's Future Quake"

Published 09/06/2006

What would happen to Los Angeles if a magnitude 7.7 earthquake ruptured along the southern San Andreas fault? For the first time, National Geographic Explorer will follow a realistic simulation that reveals the details of second-by-second events as this possible quake unleashes its phenomenal power against this mega-city city of 11 million people.

The viewer will ride with the earthquake waves, simulated on supercomputers at the San Diego Supercomputer Center (SDSC) at UC San Diego, following their progress across the landscape. The program airs on the National Geographic Channel on both Wednesday, September 6 at 5:00 p.m. and 8:00 p.m. Pacific time, and again on Saturday, September 9 at 7 p.m. and 10 p.m. Pacific time.

The show features movies of the fast-moving earthquake waves by SDSC visualization scientist Amit Chourasia, based on earthquake simulation scenarios on the San Andreas Fault carried out in the TeraShake collaboration between SDSC staff, earthquake scientists of the Southern California Earthquake Center (SCEC) at USC, San Diego State University (SDSU), and other institutions. The program also includes Chourasia's visualizations of simulations of earthquakes on the Puente Hills Fault.

"Visual imagery is intuitively understood by humans and acts as a great discovery and analysis tool," said Chourasia. "It's exciting when computer simulations and visualizations carried out for scientific research can also be directly used to help communicate the awesome forces of earthquakes to the general public."

The TeraShake simulations, which use an earthquake model developed by Kim Olsen, associate professor of geological sciences at SDSU, are the most realistic yet of where the most intense ground motion may occur in Southern California during a magnitude 7.7 San Andreas Fault earthquake.

These state-of-the-art simulations are the result of close, long-term collaboration between SCEC researchers and experts from groups across SDSC in a Strategic Applications Collaboration. "To solve the novel challenges that emerge when scientists run their codes at the largest scales and data sets grow huge, we worked closely with the scientists through months of code porting, new feature integration, and optimization," said SDSC computational scientist Yifeng Cui.

The highly detailed TeraShake simulations, run at 200 meter resolution over the immense volume with some 1.8 billion grid points, ran for four days on SDSC's 15.6 Teraflops (one trillion calculations per second) DataStar supercomputer, requiring a complex choreography of data movement between DataStar, disk, and archival storage. The dozens of terabytes of output data (more than the digital text equivalent of the Library of Congress printed collection) is archived in the SCEC Digital Library, managed by the SDSC Storage Resource Broker at SDSC, where it is easily available to researchers for further analysis.

While the larger simulated 7.7 earthquake on the San Andreas Fault is seen to inflict considerable potential damage on Los Angeles, because the epicenter is some distance from the city it is not the total devastation often depicted in disaster films. The Puente Hills event, however, though smaller, is expected to cause far more damage because it is located within the Los Angeles basin itself. Fortunately, scientists believe it represents a rare event.