Los Angeles ( CNN ) -- A high-frequency radar in California detected the March 11 tsunami that devastated Japan , raising hopes for the development of a new early warning system , a University of California at Davis oceanographer said . It was the first time a tsunami has been observed on radar , said Professor John Largier , an oceanographer at the University of California at Davis and an author of a new paper describing the work . `` We have the hardware set up . We have the system operational . It 's a software challenge that we show we can achieve '' for the West Coast , Largier told CNN Tuesday . His paper appears this month in the journal Remote Sensing . A consortium of universities in California already has a high-frequency radar system set up for the West Coast to detect changes in the ocean 's currents . To develop an early warning system for tsunamis on the West Coast , software would be needed , Largier said . Such a detection system could provide a 15-minute warning for a tsunami approaching northern California and an early warning of an hour for southern California , where the shallow continental shelf along the coast is bigger , Largier said . The U.S. East Coast and southeast Asia would have to set up a system and software from scratch , but an early detection system could provide an hour 's warning for the Eastern Seaboard and several hours for southeast Asia , where the coastal shallow waters are much bigger , Largier said . For the past decade , Largier and his colleagues have used a high-frequency radar array at the university 's Bodega Marine Lab to study ocean currents off California . That radar array is state-funded , but researchers are concerned about the costs of continuing to operate it , Largier said . Researchers from Hokkaido and Kyoto universities in Japan and San Francisco State University and Largier used data from radar sites at Bodega Bay ; Trinidad , Calif. ; and two sites in Hokkaido , Japan , to look for the tsunami offshore . The radar does n't pick up the actual tsunami but rather changes in currents as the wave travels , the scientists said . As the waves enter shallower coastal water over the continental shelf , they slow down , increase in height and decrease in wavelength , the scientists said .
A tsunami has been observed for the first time on radar , an oceanographer says . That was the March 11 tsunami that devastated Japan . The West Coast already has a high-frequency radar system for the ocean . Southeast Asia , parts of the U.S. East Coast would have to build radar systems from scratch .