Science

Japanese tsunami trash still crossing Pacific, headed toward Alaska

Scooting atop the waves like a flotilla of wind-driven beach balls -- or maybe a fleet of errant, unmanned kayaks -- hundreds of buoys flushed to sea when a catastrophic tsunami struck northeastern Japan last March have already crossed the Pacific Ocean and made landfall on beaches from Kodiak Island to Oregon, says a Washington oceanographer who pioneered the tracking of flotsam across the world's seas.

More are coming. Maybe even to the beaches of upper Cook Inlet -- Kenai, Nikiski, and the silt-laden shores of Alaska's largest city.

"I've seen debris from the Pacific go all the way up to the Forelands area, so you'd find them all the way to (there), I'm sure," said Curtis Ebbesmeyer, known for his study of trans-oceanic journeys by spilled rubber duckies and Nike shoes. "Anchorage is a little rarer, but I would encourage people . . . to look."

Through February, at least 350 buoys of three different styles now in use by Japan's oyster fishery -- and photographed amid tsunami debris shortly after the disaster -- have been reported by 45 different beachcombers in the three Pacific Coast states, British Columbia and Alaska.

"The arrival of these buoys is unprecedented," Ebbesmeyer told Alaska Dispatch in a telephone interview on Wednesday. "Yes, they've washed up over the years, here and there, but never in these numbers. The arrival rate is 167 times the historical arrival rate.

"When you look at the data, you cannot escape what's going on," he added. "And we actually have traced a few of the buoys to actual, individual oyster farms."

Despite that view, a team of ocean current modelers and federal marine debris experts announced that no material from the tsunami has yet been confirmed in North America -- including the buoys reported to Ebbesmeyer by Alaska beachcombers since last year.

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"The first bits of tsunami debris are estimated to make landfall this winter on small atolls northwest of the main Hawaiian Islands," reported Audrey McAvoy in this Associated Press story. "Other pieces are expected to reach the coasts of Oregon, Washington state, Alaska and Canada between March 2013 and March 2014."

Any buoys would have had to travel faster than ocean currents to reach Alaska if they had been set loose by the March 11 disaster, NOAA tsunami marine debris coordinator Ruth Yender told an online news conference.

"Similar buoys have washed ashore in Alaska and the U.S. West Coast before the tsunami," she said in the story.

These NOAA modelers have simply underestimated the speed that flotsam can skim across the ocean when driven by wind, Ebbesmeyer said. Their estimates are based on how fast low-floating items like lumber might travel and don't take into account how "windage" can propel the relatively light buoys.

Aside from this mistake in the calculations, they're ignoring the gritty, surf-tossed evidence that he and his small army of volunteer beachcombers have amassed over the past six months, he said.

"There's 'legally confirmed' and there's 'as good as it gets,'" Ebbesmeyer said. "The Japanese Consulate and NOAA want to only deal with debris that is like a house with a street number on it or a boat with a name on it. Unfortunately, 99.9 percent of the debris from the tsunami will not carry a definitive tag, if you will."

Massive catastrophe spawns massive flotilla of trash

When a magnitude 9.0 megathrust earthquake rocked the ocean floor 45 miles east of the Tohoku region in northern Japan on March 11 last year, a tsunami swept inland with 130-foot waves, leveling cities and towns, killing thousands of people. Everything that might float away -- the detritus of modern civilization -- was flushed into the ocean as the waves receded.

"If you put a major city through a trash grinder and sprinkle it on the water, that's what you're dealing with," is how Ebbesmeyer described the situation in an AP story last spring.

The destruction created up to 25 million tons of debris, with as much as 2 million tons remaining in the ocean, the AP story reported. Most of that is expected to sink or get caught up in a trash gyre known as the Great Pacific Garbage Patch, with only 1 to 5 percent eventually reaching American and Canadian beaches.

As time passed, scientists and oceanographers have tried to get a fix on the location and status of this flotsam and debris on its slow journey across the Pacific Ocean. Here is an animation showing how it might be morphing.

It's not due to morbid curiosity. The material could ensnare marine life, pollute beaches and possibly include human remains. (Early fears that some of the material might contain radioactive material from nuclear power plants damaged during the disaster largely have been discounted, Yender said in the AP story.)

The goal is to be prepared when it begins washing ashore or endangering sea life, adding to a worldwide epidemic of human refuse and floatable trash spreading across the world's seas. The items range from mile-long ghost nets that strangle marine life to tiny particles that appear almost indistinguishable from plankton, the foundation of the marine food web.

At least 267 species across the world regularly suffer injury from getting snared or eating debris -- including most sea turtle species, almost half of all seabirds and 43 percent of marine mammals, according to a United Nations report.

By now, much of the tsunami trash has spread out across thousands of square miles, with individual pieces floating alone rather than in dense, easily located rafts, the scientists said.

"The major question is how much of that material sank since last year, and how much remains afloat or still in the water column," said Nicholas Mallos, a conservation biologist and marine debris specialist for the Ocean Conservancy, in this story.

"In many cases it's not density that matters, it's total amount," added Nikolai Maximenko, with the International Pacific Research Center at the University of Hawaii. "For example, if there's a current flowing around Midway Island, that island would collect debris like a trawl moving across the ocean. It will collect all the debris on its way."

Federal scientists are now starting to fly on Coast Guard patrols of the Hawaiian archipelago to watch for debris, Yender said. Other scientists are being asked to start searching for landfalls in Midway and other atolls.

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Has some tsunami flotasm already arrived?

A major reason Ebbesmeyer believes the hundreds of buoys that have washed up on Alaska and the Pacific beaches since last fall originated with the Japanese tsunami is that they arrived on schedule. A long-tested computer model developed by his colleague, Jim Ingraham, accurately predicted the arrival of 10 to 20 buoys at various locales. It's a model that has been tested with the trajectory of other buoys in the past.

The crux is understanding the wind's power to move light objects across the water, he said.

"I found a long time ago that if you don't carefully address windage, you can't explain the drift of an object, and unfortunately the people who run computer models don't get out in the field," Ebbesmeyer said.

In this case, he said, the buoys in question were predicted to travel across the ocean at about 23 miles per day -- about 1 mph. The NOAA model, Ebbesmeyer said, predicts tsunami debris will move much more slowly, at about 7 miles per day.

That might be likened to the difference between a boat and a floating log, he said. Dump a batch of kayaks into the ocean off Japan next to a raft of logs. Which ones catch the wind and start moving?

"The kayaks will get across the ocean in seven months, and all that lumber will take a couple years."

But Ebbesmeyer isn't relying on his model. He's relying on dozens of gum-booted tideline strollers, all working the beaches from the Olympic Peninsula to Yakutat in their spare time. "I've got all the grunts out there, the beachcombers, and they're faithful. They're careful, they're reporting in. And I'm just the collection person."

Add it all up.

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• Three kinds of buoys congregated in Japan after the tsunami and later showed up in similar proportions on the Pacific Coast;

• Unprecedented numbers of buoys arriving in a short span;

• The close match to predictions by the Ingraham's computer model; and

• A few confirmations by oyster farmers.

"This is as good as beachcombing ever gets. This is as good as flotsam ever gets," Ebbesmeyer said. "The only thing that would be better would be a boat with a name on it. Or a house with a street number on it."

Contact Doug O'Harra at doug(at)alaskadispatch.com

Got flotsam?

If you've come across possible tsunami trash along Alaska beach, please send an email (with photo attached if possible) to eric@alaskadispatch.com. Also report it to Curt Ebbesmeyer at http://www.flotsametrics.com/contact.php

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