The operator of the stricken Fukushima nuclear plant has been dumping something like a thousand tons per day of radioactive water into the Pacific ocean.
Most people assume that the ocean will dilute the radiation from Fukushima enough that any radiation reaching the West Coast of the U.S. will be low.
For example, the Congressional Research Service wrote in April:
Scientists have stated that radiation in the ocean very quickly becomes diluted and would not be a problem beyond the coast of Japan.
U.S. fisheries are unlikely to be affected because radioactive material that enters the marine environment would be greatly diluted before reaching U.S. fishing grounds.
And a Woods Hole oceanographer said:
“The Kuroshio current is considered like the Gulf Stream of the Pacific, a very large current that can rapidly carry the radioactivity into the interior” of the ocean, Buesseler said.
“But it also dilutes along the way, causing a lot of mixing and decreasing radioactivity as it moves offshore.”
But – just as we noted 2 days after the earthquake hit that the jet stream might carry radiation to the U.S. by wind – we are now warning that ocean currents might carry more radiation to the at least some portions of the West Coast of North America than is assumed.
Specifically, we noted more than a year ago:
The ocean currents head from Japan to the West Coast of the U.S.
As AP notes:
The floating debris will likely be carried by currents off of Japan toward Washington, Oregon and California before turning toward Hawaii and back again toward Asia, circulating in what is known as the North Pacific gyre, said Curt Ebbesmeyer, a Seattle oceanographer who has spent decades tracking flotsam.
“All this debris will find a way to reach the West coast or stop in the Great Pacific Garbage Patch,” a swirling mass of concentrated marine litter in the Pacific Ocean, said Luca Centurioni, a researcher at Scripps Institution of Oceanography, UC San Diego.
Here is what the North Pacific Gyre looks like:
CNN said that “the Hawaiian islands may get a new and unwelcome addition in coming months — a giant new island of debris floating in from Japan.” It relied in part on work done by the University of Hawaii’s International Pacific Research Center, which predicts that:
“In three years, the [debris] plume will reach the U.S. West Coast, dumping debris on Californian beaches and the beaches of British Columbia, Alaska, and Baja California. The debris will then drift into the famous North Pacific Garbage Patch, where it will wander around and break into smaller and smaller pieces. In five years, Hawaii shores can expect to see another barrage of debris that is stronger and longer lastingthan the first one. Much of the debris leaving the North Pacific Garbage Patch ends up on Hawaii’s reefs and beaches.”
Indeed, CNN notes:
The debris mass, which appears as an island from the air, contains cars, trucks, tractors, boats and entire houses floating in the current heading toward the U.S. and Canada, according to ABC News.
The bulk of the debris will likely not be radioactive, as it was presumably washed out to sea during the initial tsunami – before much radioactivity had leaked. But this shows the power of the currents from Japan to the West Coast.
An animated graphic from the University of Hawaii’s International Pacific Research Center shows the projected dispersion of debris from Japan:
In addition to radioactive debris, MIT says that seawater which is itself radioactive may begin hitting the West Coast within 5 years. Given that the debris is hitting faster than predicted, it is possible that the radioactive seawater will as well.
And the Congressional Research Service admitted:
However, there remains the slight potential for a relatively narrow corridor of highly contaminated water leading away from Japan …
Transport by ocean currents is much slower, and additional radiation from this source might eventually also be detected in North Pacific waters under U.S. jurisdiction, even months after its release. Regardless of slow ocean transport, the long half-life of radioactive cesium isotopes means that radioactive contaminants could remain a valid concern for
Indeed, nuclear expert Robert Alvarez – senior policy adviser to the Energy Department’s secretary and deputy assistant secretary for national security and the environment from 1993 to 1999 – wrote yesterday:
According to a previously secret 1955 memo from the U.S. Atomic Energy Commission regarding concerns of the British government over contaminated tuna, “dissipation of radioactive fall-out in ocean waters is not a gradual spreading out of the activity from the region with the highest concentration to uncontaminated regions, but that in all probability the process results in scattered pockets and streams of higher radioactive materials in the Pacific. We can speculate that tuna which now show radioactivity from ingested materials [this is in 1955, not today] have been living, in or have passed through, such pockets; or have been feeding on plant and animal life which has been exposed in those areas.”
Because of the huge amounts of radioactive water Tepco is dumping into the Pacific Ocean, and the fact that the current pushes waters from Japan to the West Coast of North America, at least some of these radioactive “streams” or “hot spots” will likely end up impacting the West Coast.