LOS ANGELES - Volunteers who patrol California beaches for plastic, cigarette butts and other litter will be on the lookout this winter for flotsam from last year's monstrous tsunami off Japan's coast.
Armed with index-size cards, beachcombers will log water bottles, buoys, fishing gear and other possessions that might have sailed across the Pacific to the 1,100-mile shoreline.
The March 2011 disaster washed about 5 million tons of debris into the sea. Most of that sank, leaving an estimated 1 1/2 million tons afloat. No one knows how much debris - strewn across an area three times the size of the United States - is still adrift.
Tsunami flotsam has already touched the Pacific Northwest and Hawaii this year. The West Coast is bracing for more sightings in the coming months as seasonal winds and coastal currents tend to drive marine wreckage ashore.
Like the past winter, scientists expect the bulk of the debris to end up in Alaska, Washington state, Oregon and British Columbia. Last week, the Coast Guard spotted a massive dock that possibly came from Japan on a wilderness beach in Washington state.
Given recent storm activity, Northern California could see "scattered and intermittent" episodes, said Peter Murphy, a marine debris expert at the National Oceanic and Atmospheric Administration, which recently received a $5 million donation from Japan to track and remove tsunami debris.
To prepare, state coastal regulators have launched a cleanup project to document possible tsunami items that churn ashore. Working with environmental groups, volunteers will scour beaches with a checklist. It's like a typical beach cleanup, but the focus will be to locate articles from Japan.
Until now, efforts in California have been haphazard. The goal is to organize tsunami debris cleanups at least once every season stretching from the Oregon state line to the Mexican border and then posting the findings online.
Debris from Asia routinely floats to the U.S. It's extremely difficult to link something back to the Japanese tsunami without a serial number, phone number or other marker.
Of the more than 1,400 tsunami debris sightings reported to NOAA, the agency only traced 17 pieces back to the event, including small fishing boats, soccer balls, a dock and a shipping container housing a Harley-Davidson motorcycle with Japanese license plates. No confirmed tsunami debris so far has reached California.