USC News

Menu Search

Experts Help Redraw Tsunami Hazard Maps

Experts Help Redraw Tsunami Hazard Maps
Aggeliki Barberopoulou of the USC Tsunami Research Center

Costas Synolakis, Jose Borrero and Aggeliki Barberopoulou of the USC Tsunami Research Center provided basic research for a new set of inundation maps recently released jointly by USC, the California Geological Survey and the California Emergency Management Agency.

The large-scale maps, accessible on the California Department of Conservation Web site (, show all the counties in the state, from Del Norte to San Diego County.

On each map, a red line shows the best estimate for “the largest anticipated tsunami event, plus a high tide,” according to geologist John Parrish of the California Geological Survey, who presented the maps at a San Francisco meeting of the American Geophysical Society shortly before the fifth anniversary of the Dec. 26, 2004 tsunami in the Indian Ocean.

Borrero, a member of the Sonny Astani Department of Civil and Environmental Engineering, began the actual painstaking computer simulations that made the calculation – work later taken over and completed by Barberopoulou, working with Synolakis.

Detailed simulation is required because tsunami effects are heavily dependent on the orientation of the coastline (whether or not it faces likely earthquake areas), the shape of the shoreline (some formations can focus waves as they come ashore, making the crests higher) and the local topography near the ocean (hilly coasts are safer than beaches with flat topography). When all the factors combine to maximize impact, the waves can be as high as 45 feet in Crescent City in Northern California.

Some 350,000 Californians live in areas subject to potential inundation, according to the study.

More stories about:

Experts Help Redraw Tsunami Hazard Maps

Top stories on USC News