A massive trail of debris from the devastating tsunami that struck Japan in March of 2011 is slowly making its way across the Pacific Ocean en route to the West Coast of the United States, where scientists are predicting it will arrive in the next two to three years – right on schedule.
The mass of debris, weighing millions of tons and forming a trail a thousand miles long, will likely strike Oregon and Washington, according to models based on winds and currents.
But new accounts of where the trail has progressed suggest that at least some of that debris may peel off and enter the infamous “Garbage Patch,” a huge gyre in the Pacific where plastic and other debris has accumulated over the years, according to Jack Barth, an Oregon State University oceanographer and an expert on Pacific Ocean currents and winds.
“Recent reports of debris are from farther south than the axis of the main ocean currents sweeping across the north Pacific toward Oregon,” said Barth, a professor in OSU’s College of Oceanic and Atmospheric Sciences. “This means a fair amount of debris may enter the patch. We should still see some of the effects in Oregon and Washington, but between some of the materials sinking, and others joining the garbage patch, it might not be as bad as was originally thought.”
Barth said as time goes on, more of the materials will sink as they become waterlogged, or become heavy from barnacles and other organisms growing on them.
Conversely, he said, items of debris that are higher in the water and can be caught by the winds – such as small boats – may arrive more quickly than anticipated. The “westerlies,” as these winds are called, blow straight across the Pacific Ocean from Japan to the Pacific Northwest coast “and they can be pretty strong,” Barth pointed out.
Recent reports that the debris is ahead of schedule don’t match Barth’s calculations, which suggest that the bulk of the debris should arrive along the West Coast in 2013 to 2014. It appears to be moving about 10 miles a day, he said.
Fears of contamination from the debris are largely unfounded, Barth said. The OSU scientist just returned from a meeting of PICES - the North Pacific Marine Science Organization, where Japanese scientists reported that radiation levels in the waters off the Japanese coast were below a safe threshold.
“The dilution power of the Pacific Ocean is enormous,” Barth said.
Barth led a five-year study a decade ago looking at how water moves off the Oregon coast in the aftermath of the 1999 shipwreck of the New Carissa. Hundreds of gallons of oil leaked from the vessel and despite sophisticated ocean current models, the fuel appeared in places that surprised scientists.
Although the westerlies will bring some of the debris toward the Northwest coast, what happens as it arrives near the shore will depend on the time of year, Barth said.
“One thing we learned from the New Carissa, is that when things get dumped off the Oregon coast in winter, they go quickly northward,” Barth pointed out. “If the debris arrives in the winter, some of it may get pushed up to Vancouver Island. If it gets here in the summer, it is more likely to drift down to the south.”
Local winds can further confuse the issue, keep debris off-shore in the summer when the winds are from the north, and pushing it on-shore in the winter.
The estimated 5 million to 20 million tons of debris sucked into the ocean during the massive tsunami is due to hit Hawai’i in 2013, according to University of Hawa’i at Manoa scientists.
Nikolai Maximenko, a senior researcher at UH Manoa’s International Pacific Research Center, and scientific computer programmer Jan Hafner, developed a computer model of ocean currents earlier this year to speculate where the debris might end up. Now, valuable sightings of the debris are being reported by sailing ships from area where the model predicted.
Ever since the tsunami scientists at the University of Hawai‘i at Manoa’s International Pacific Research Center have been trying to track the trajectory of this debris that can threaten small ships and coastlines.
Warned by maps of the scientists’ model, the Russian sail training ship, the STS Pallada, recently found an array of unmistakable tsunami debris on its homeward voyage from Honolulu to Vladivostok.
Soon after passing Midway Islands, Pallada spotted surprising number of floating items. “On Sept. 22, in position 31042,21 N and 174045,21 E, we picked up on board the Japanese fishing boat. Radioactivity level – normal, we’ve measured it with the Geiger counter,” wrote Natalia Borodina, information and education mate of the Pallada. “At the approaches to the mentioned position (maybe 10-15 minutes before) we also sighted a TV set, fridge and a couple of other home appliances.”
Borodina adds on Sept. 27 that “we keep sighting everyday things like wooden boards, plastic bottles, buoys from fishing nets (small and big ones), an object resembling wash basin, drums, boots, other wastes. All these objects are floating by the ship.”
On Oct. 8, the Pallada entered the port of Vladivostok. The most remarkable photo taken of the voyage is of a small fishing vessel about 20 feet long, which they were able to hoist up on to the Pallada. The markings on the wheel house of the boat show its home port to be in the Fukushima Prefecture, the area hardest hit by the tsunami.
With the exact locations of some of the by now widely scattered debris, scientists can make more accurate projections about when the debris might arrive at the Papahanaumokuakea Marine National Monument. The first landfall on Midway Islands is anticipated this winter. The debris that misses Midway will continue toward the main Hawaiian Islands and the North American West Coast.