Where All the Debris From Japan's Tsunami Went

When a tsunami devastated entire cities in Japan (and started the ongoing Fukushima nightmare), it created nearly 25 million tons of debris, with much of it washing away in the Pacific Ocean. The question is: Where did it all go?

We know what happened to bits and pieces of it: An entire pier washed up on the coast of Oregon several months after the tsunami, and lots of other detritus have shown up on the coasts of Hawaii, Alaska, and the Pacific Northwest. But there are still millions of tons of pollution that remain unaccounted for out there—a new model from researchers at the University of Hawaii can give us a clue to where it all went.

According to Jan Hafner, who presented her research at the 2014 Ocean Sciences Meeting in Honolulu, debris likely crossed the north Pacific and eventually landed in the Gulf of Alaska before migrating down across much of the west coast of the United States. From there, some of the debris has made it back past Hawaii and into the middle of the Pacific, with small parts making it all the way back to Japan.

Since the storm, the International Pacific Research Center at the University of Hawaii has been closely tracking winds and ocean currents and has kept details of anecdotal accounts of debris coming ashore. They’ve also been tracking debris near the Philippines since super typhoon Haiyan hit last November.

About a year and a half after the March, 2011 disaster, fishing boats, buoys, small refrigerators, and other pieces of wreckage that float began washing up in Hawaii. Later, about two and a half years after the storm, pipes and poles and pieces of wood that sit further below the surface arrived.

There’s not really a great way of actually tracking where the debris has gone—doing so would be extremely costly and perhaps impossible for much of the smaller pieces—but Hafner says her model lines up with anecdotal evidence of what has already been found.

“While marine debris observing system that could provide data for quantitative verification of the model is nonexistent, model results were found consistent with scarce reports from the coastline and the sea in terms of timing and dynamical composition,” she wrote.

Going forward, it looks like much of the debris may make its way into the North Pacific gyre, which might sound familiar to you because it’s the spot of the Great Pacific Garbage Patch, a vast wasteland of micro plastics, trash, and other debris. Hafner doesn’t have an estimate for how much of the tsunami’s debris could eventually end up there, but given the Pacific Ocean’s natural currents, that’s probably where a lot of it will stay. And that's a bummer, because we don't really have a good way of cleaning any of this stuff up.