Oceanographers from ASR Ltd., a Raglan, New Zealand based marine consulting and research company, have been using computer models to track the progress and likely position of the massive amounts of debris washed in to the Pacific Ocean by the Japan Tsunami.

Within a days of the tsunami, after seeing media reports of large amounts of debris washed in to the sea, the team launched a computer simulation designed to follow the progress of the material as it was pushed along by ocean currents. Their results have been available on the web since then, and now a year later, it seems their predictions match what is being observed.

“Our results show that the first bits of debris should be reaching the area around Midway atoll and the northern Hawaiian Islands around now” say project leader Laurent Lebreton “this is being confirmed by data coming back from research boats searching that area”.

This team’s approach differs from other researchers in two important ways. Firstly they use information on the size of the tsunami combined with coastal population density in Japan to more accurately estimate the amount and location of debris washed in to the sea. Secondly, they use data based on real ocean currents to model the movement of the debris since the tsunami. By using data from past years, they can deduce how far and how fast the debris has moved.

“The westward pace of the debris field is slowing” adds Lebreton “the stuff could have moved as far as 1500 km in the first month due to strong currents near Japan. But now that it is in the deep ocean, currents are slower and it has taken another 11 months to move the 4,000 extra kilometres to Hawaii.”

According to their studies, large amounts of debris shouldn’t hit the California coast for a few years – If at all – with most of the material staying at sea. Jose Borrero, a researcher ASR who also contributed to the project says “Based on the model, most of the debris will be sucked in to the North Pacific subtropical gyre – what people like to call ‘The Great Pacific Garbage Patch’.”

ASR’s research is unique in that it was done without any government or research funding. “We knew we had the right tools to do this work” say Lebreton “so we kept working at it over the past out of our own personal interest.“

“We hope our work will be noticed by the international community” add Borrero, “There are a lot of groups studying this issue worldwide and we’d like to get our results in to the mix. We don’t have any research funding, so it has been all done on our own time, which makes it hard to get noticed.”

The paths of tsunami debris form Japan across the Pacific Ocean. Colours represent possible positions after particular time intervals from 1 month to 4 years.