Using data from tide gauges and deep-ocean pressure sensors, Cheung and his graduate students developed a computer algorithm to reconstruct the earthquake rupture and estimate possible tsunami hazards across the Pacific Ocean. They have validated the formula with data from the 1964 Prince William Sound and 1996 Andreanov earthquakes in Alaska, the 1944 Tonakai and 1994 Kuril earthquakes near Japan, and the 1995 Antofagasta earthquake in Chile.

"This method has taken the guesswork out of the tsunami-warning procedures," Cheung said. "Instead of looking at water-level data near the tsunami source and trying to figure out what might happen several thousand miles away, we can actually use the water-level data to calculate the tsunami waveforms anywhere in the Pacific basin."

The research is having far-reaching impacts. The National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory, its center for tsunami research, has adapted this mathematical formula into a tsunami-forecasting tool. The Chilean Navy is now implementing this tsunami-forecasting method and, starting this month, has an oceanographer at the University of Hawai'i working directly with Cheung.