There are estimates that as much as 25 million tons of debris is headed toward Southern California, but predicting when it will arrive is difficult.

"Can you predict the weather two weeks from now? No. It's like the weather. This is driven by weather," said Menas Kafatos, Dean, Schmid College of Science.

Scientists at Chapman University are using computer models to mathematically track the path Japan's tsunami debris should take across the Pacific.

Experts predict winds will push what's been called a giant garbage patch -- with boats, homes and cars that were swept out to sea. By now they believe much of what was washed away has sunk.

"I imagine what remains is things that float easily, like plastic bottles, wood, things of that sort," Kafatos said. "It's bad for environment. It's bad for marine life."

The tsunami flooded hundreds of miles along the coast of Japan, killing between 15,000 and 19,000 people.

"Most of the debris came from cities," Kafatos said. "All these costal areas and villages. That will not be radioactive."

Some of the debris has already been spotted near Hawaii. Scientists expect some tsunami trash to hit Seattle next year and then head south.

NOAA is tracking the debris as best they can and they're asking for help from the public.

If you find anything on the beach that you think may be debris from the tsunami, you can e-mail your report to NOAA. They'd like to see a photo as well.

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