Japan tsunami debris field approaches Hawai`i

The Japanese tsunami of March 11, 2011, dumped millions of tons of debris into the ocean, setting it adrift on the surface of the North Pacific—and some will be in Hawai`i soon.

(Image: Computer model of the Japan tsunami debris field on Dec. 13, 2011. Credit: IPRC/SOEST, University of Hawai`i.)

Some of that material should get to the Hawaiian Islands via a fairly direct southern route, while some will sweep across the northern Pacific, down the West Coast, and back to Hawai'i.

The first pulse of that stuff should arrive in the Hawaiian archipelago from the west this winter, and a second major pulse could arrive on the trades from the northeast in three or four years, according to Nikolai Maximenko, oceanographer with the University of Hawai`i's International Pacific Research Center.

The federal government's best guess for when it hits our beaches in the main islands is 2014 to 2015, said Carey Morishige, Pacific Islands Regional Coordinator of NOAA's Marine Debris Program.

And with respect to radioactivity from Japan's nuclear powerplant disasters, the residual radiation might be detectable with extremely sensitive laboratory equipment, but should be no health hazard to anyone in the Hawaiian Islands, said radiochemist Henrieta Dulaiova, of the University of Hawai`i's Department of Geology and Geophysics.

They spoke Dec. 10, 2011, at a Kaua`i conference sponsored by the Surfrider Foundation.

An estimated 20-25 million tons of debris was estimated by the Japanese government to have been created when the tsunami hit Japan's shores. Of that, Maximenko said, a third to a quarter was pulled into the ocean. And a lot of that material likely sank. More has dispersed widely, and it's likely that a large amount of what's left will be trapped in the massive Eastern Pacific gyre known as the Great Garbage Patch.

A 15-year progression of how the debris is likely to move can be found here.

You can see it catching the fringes of the Main Hawaiian Islands, and settling in the Garbage Patch.

Maximenko said the first of the remaining debris could be arriving at the western end of the Hawaiian archipelago any day now. A Russian sail training ship spotted debris 250 miles from Midway Atoll in September. The material spotted included lumber, household appliances like refrigerators and televisions, washbasins, boots and other stuff. They even picked up an empty Japanese fishing boat, drifting amid the debris.

Maximenko said the debris should move inexorably down the chain, first Kure and Midway, then the nearer islands of the Papahanaumokuakea refuge, and then Kaua`i.

“From the times of arrival and composition, we hope to learn much,” Maximenko said. His model for how the debris may be moving can be found here.

A number of frequently asked questions are answered at this NOAA marine debris site. Basic information about marine debris is here.

Surfrider and the NOAA marine debris program will be monitoring the coastlines and setting up programs to deal with the arrival of Japan tsunami debris. RaisingIslands invites folks with information on the subject to add to the comment selection on this post.

© Jan TenBruggencate 2011