More than a million tons of debris are moving across the North Pacific. They're being monitored closely, and scientists expect the first pieces to arrive in northern Hawaii soon.
The rest of the West Coast is expected to see debris around 2014.
The National Oceanic and Atmospheric Administration said agency workers were boarding Coast Guard flights that patrol the archipelago. NOAA also asked scientists stationed at Midway and other atolls to look for the debris.
In September, a Russian training ship spotted a refrigerator, a television set and other appliances west of Hawaii. By now, the debris has likely drifted so far apart that only one object can be seen at a time, said Nikolai Maximenko, a University of Hawaii researcher and ocean currents expert.
One to 2 million tons of debris remain in the ocean, but only one to 5 percent of that could reach Hawaii, Alaska, Oregon, Washington state and Canada's British Columbia, Maximenko said.
So far, no debris confirmed to be from the tsunamis has landed on American shores. Officials say there is little chance of debris being contaminated by radiation.
The Associated Press contributed to this report.