Category Archives: Japan Tsunami

Fukushima Dumps First Batch of Once-Radioactive Water in Sea

Water tanks holding contaminated water in front of the reactor buildings at Fukushima Daiichi. February 11th, 2015. Captions And Photo source: ©© IAEA Imagebank


Japan’s crippled Fukushima nuclear plant Monday began releasing previously contaminated water into the sea, but the man tasked with preventing another meltdown warned other highly radioactive fluid still stored on site could pose a major threat…

Read Full Article, AFP

Examining the Fate of Fukushima Contaminants, WHOI (08-20-2015)

Fukushima Operator Finds New Source of Radiation Leak into Sea, Reuters (02-25-2015)

Fukushima Accident Still Ongoing After Three Years: Q&A, IPS News (06-20-2014)

Examining the Fate of Fukushima Contaminants

Japan. Photo source: ©© Robertodevito

By © Woods Hole Oceanographic Institution;

An international research team reports results of a three-year study of sediment samples collected offshore from the Fukushima Daiichi Nuclear Power Plant in a new paper published August 18, 2015, in the American Chemical Society’s journal, Environmental Science and Technology.

The research aids in understanding what happens to Fukushima contaminants after they are buried on the seafloor off coastal Japan.

Led by Ken Buesseler, a senior scientist and marine chemist at the Woods Hole Oceanographic Institution (WHOI), the team found that a small fraction of contaminated seafloor sediments off Fukushima are moved offshore by typhoons that resuspend radioactive particles in the water, which then travel laterally with southeasterly currents into the Pacific Ocean.

“Cesium is one of the dominant radionuclides that was released in unprecedented amounts with contaminated water from Japan’s Fukushima Daiichi nuclear power plant following the March 11, 2011, earthquake and tsunami,” says Buesseler. “A little over 99 percent of it moved with the water offshore, but a very small fraction—less than one percent—ended up on the sea floor as buried sediment.”

“We’ve been looking at the fate of that buried sediment on the continental shelf and tracking how much of that contaminated sediment gets offshore through re-suspension from the ocean bottom,” he adds.

The research team, which included colleagues from the Japan Agency for Marine-Earth Science and Technology and the Japan Atomic Energy Agency, analyzed three years’ worth of data collected from time-series sediment traps.

Researchers deployed the pre-programmed, funnel-shaped instruments 115 kilometers (approximately 70 miles) southeast of the nuclear power plant at depths of 500 meters (1,640 feet) and 1,000 meters (3,280 feet). The two traps began collecting samples on July 19, 2011—130 days after the March 11th earthquake and tsunami—and were recovered and reset annually.

After analyzing the data, researchers found radiocesium from the Fukushima Daiichi Nuclear Power Plant accident in the sediment samples along with a high fraction of clay material, which is characteristic of shelf and slope sediments suggesting a near shore source.

“This was a bit of a surprise because when we think of sediment in the ocean, we think of it as sinking vertically, originating from someplace above. But what this study clearly shows is that the only place that the material in our sediment traps could have come from was the continental shelf and slope buried nearshore. We know this because the coastal sediments from the shelf have a unique Fukushima radioactive and mineral signal,” says Buesseler.

The data also revealed that peak movements of the sediments with radiocesium coincided with passing typhoons which likely triggered the resuspension of coastal sediments. Radiocesium was still detected in sediment samples from July 2014.

“The total transport is small, though it is readily detectable. One percent or less of the contaminated sediment that’s moving offshore every year means things aren’t going to change very fast,” Buesseler says. “What’s buried is going to stay buried for decades to come. And that’s what may be contributing to elevated levels of cesium in fish—particularly bottom-dwelling fish off Japan.”

While there were hundreds of different radionuclides released from the Fukushima Daiichi Nuclear Power Plant during the disaster, after the initial decay of contaminants with half lives (the time it takes for one half of a given amount of radionuclide to decay) less than days to weeks, much of the attention has remained focused on cesium-137 and-134— two of the more abundant contaminants. Cesium-134 has a half-life of a little over two years, and so any found in the ocean could come only from the reactors at Fukushima. Cesium-137 has a half-life of roughly 30 years and is also known to have entered the Pacific as a result of aboveground nuclear weapons tests in the 1950s and ‘60s, providing a benchmark againstwhich to measure any additional releases from the reactors.

In October, Buesseler and the research team will return to Japan to redeploy more sediment traps. The continued study will help estimate how long it takes to decrease the level of radiocesium in seafloor sediments near the Fukushima Daiichi Nuclear Power Plant.

The research was funded initially by a Rapid Response Grant from the National Science Foundation, and continued for three years through support from the Deerbook Charitable Trust and Gordon and Betty Moore Foundation.

The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean’s role in the changing global environment. For more information, please visit

Original Article And Learn More, WHOI

Fukushima Accident Still Ongoing After Three Years: Q&A, IPS News (06-20-2014)

Tokyo Finds High Levels of Radiation in Children’s Park

Iitate, Fukushima Prefecture, Japan, 27 March 2011. Greenpeace radiation safety experts Jan Van de Putte and Jacob Namminga monitor contamination levels at Iitate village, 40km northwest of the crisis-stricken Fukushima/Daiichi nuclear plant, and 20km beyond the official evacuation zone. Radiation levels found by the Greenpeace monitoring team are far above internationally recommended limits – people living here would receive the yearly maximum dose of radioactivity within a few days, yet have not yet been evacuated. Captions and Photo source: ©© Christian Åslund / Greenpeace


Authorities in the Japanese capital have cordoned off a playground where high levels of radiation were detected this week, reviving concerns about nuclear contamination four years after the Fukushima disaster…

Read Full Article, Reuters

Fukushima Operator Finds New Source of Radiation Leak into Sea, Reuters (02-25-2015)
The operator of the tsunami-crippled Fukushima found a pool of highly contaminated water on the roof of a plant building and that it had probably leaked into the sea through a gutter when it rained…

Fukushima Accident Still Ongoing After Three Years: Q&A, IPS News (06-20-2014)

Trace Amounts of Fukushima Radioactivity Detected Along Shoreline of British Columbia

Ucluelet, British Columbia. Photo source: ©© Ernest Von Rosen

By © Woods Hole Oceanographic Institution;

Scientists at the Woods Hole Oceanographic Institution (WHOI) have for the first time detected the presence of small amounts of radioactivity from the 2011 Fukushima Dai-ichi Nuclear Power Plant accident in a seawater sample from the shoreline of North America. The sample, which was collected on February 19 in Ucluelet, British Columbia, with the assistance of the Ucluelet Aquarium, contained trace amounts of cesium (Cs) -134 and -137, well below internationally established levels of concern to humans and marine life.

The WHOI scientists, with the help of citizen volunteers, have collected samples at more than 60 sites along the U.S. and Canadian West Coast and Hawaii over the past 15 months for traces of radioactive isotopes from Fukushima. Last November, the team reported their first sample containing detectable radioactivity from Fukushima 100 miles (150 km) off shore of Northern California. However, no radiation had yet been found along any of the beaches or shorelines where the public has been sampling since 2013.

“Radioactivity can be dangerous, and we should be carefully monitoring the oceans after what is certainly the largest accidental release of radioactive contaminants to the oceans in history,” said Ken Buesseler, a marine chemist at WHOI who has been measuring levels of radioactivity in seawater samples from across the Pacific since 2011. “However, the levels we detected in Ucluelet are extremely low.”

Scientists at WHOI are analyzing samples for two forms of radioactive cesium that can only come from human sources. Cesium-137, the “legacy” cesium that remains after atmospheric nuclear weapons testing, is found in all the world’s oceans because of its relatively long, 30-year half-life. This means it takes 30 years for one-half of the cesium-137 in a sample to decay. The Fukushima reactors added unprecedented amounts of cesium-137 into the ocean, as well as equal amounts of cesium-134. Because cesium-134 has a two-year half-life, any cesium-134 detected in the ocean today can only have been added recently—and the only recent source of cesium-134 has been Fukushima.

The Ucluelet sample contained 1.4 Becquerels per cubic meter (Bq/m3) (the number of decay events per second per 260 gallons of water) of cesium-134, a telltale sign of having come from Fukushima, and 5.8 Bq/m3 of cesium-137. These levels are comparable to those measured 100 miles off the coast of Northern California last summer. If someone were to swim for 6 hours a day every day of the year in water that contained levels of cesium twice as high as the Ucluelet sample, the radiation dose they would receive would still be more than one thousand times less than that of a single dental x-ray.

Monitoring Effort

Buesseler has had to rely on a crowd-funding and citizen-science initiative known as “Our Radioactive Ocean” to collect samples because no U.S. federal agency is responsible for monitoring radiation in coastal waters. The results are publicly available on the website

“We expect more of the sites will show detectable levels of cesium-134 in coming months, but ocean currents and exchange between offshore and coastal waters is quite complex,” said Buesseler, “Predicting the spread of radiation becomes more complex the closer it gets to the coast and we need the public’s help to continue this sampling network.”

Recent partnerships between Buesseler’s group and a Canadian-funded program called InFORM, led by Jay Cullen at the University of Victoria, Canada, has added more than a dozen monitoring stations along the coast of British Columbia. In addition, upcoming cruises with the Scripps Institution of Oceanography in La Jolla, California, will add more than 10 new sampling sites offshore. Also in 2015, a National Science Foundation-sponsored project led by WHOI physical oceanographer Alison Macdonald includes funding to analyze more than 250 seawater samples collected on a research ship travelling this May between Hawaii and the Aleutian Islands, Alaska.

Original Article And Learn More, WHOI

Fukushima Radioactivity Detected Off West Coast, WHOI (11-11-2014)
Monitoring efforts along the Pacific Coast of the U.S. and Canada have detected the presence of small amounts of radioactivity from the 2011 Fukushima Dai-ichi Nuclear Power Plant accident 100 miles (150 km) due west of Eureka, California…

Japan Mulls Massive, 250-Mile Sea Wall To Fend Of Tsunamis

A man walks along the Kesennuma harbor road Thursday March 17 2011 where the tsunami deposited a large ship on the dock in the aftermath the earthquake. Captions and Photo source: ©© Warren Antiola


Four years after a towering tsunami ravaged much of Japan’s northeastern coast, efforts to fend off future disasters are focusing on a nearly 400-kilometer (250-mile) chain of cement sea walls, at places nearly five stories high.

Opponents of the 820 billion yen ($6.8 billion) plan argue that the massive concrete barriers will damage marine ecology and scenery, hinder vital fisheries and actually do little to protect residents who are mostly supposed to relocate to higher ground…

Read Full Article, Phys.Org (03-22-2015)

Seawalls in Japan Offered Little Protection Against Tsunami’s Crushing Waves, The New York Times

Japan’s tsunami waves did top historic heights (04-25-2011)
Tsunami waves topped 60 feet or more as they broke onshore following Japan’s earthquake, according to some of the first surveys measuring the impact along the afflicted nation’s entire coast. Some waves grew to more than 100 feet high, breaking historic records, as they squeezed between fingers of land surrounding port towns…

Tsunami Warnings, Written In Stone, The New York Times
The stone tablet has stood on this forested hillside since before they were born, but the villagers have faithfully obeyed the stark warning carved on its weathered face: “Do not build your homes below this point!”

Photo source: ©© Julien

New Museum Program Focuses on Impacts of Fukushima on the Ocean

Photograph: © SAF — Coastal Care

By © Woods Hole Oceanographic Institution;

Four years after the Fukushima Dai-ichi nuclear power plant accident, Japan is still recovering and rebuilding from the disaster. In March 2011 one of the largest earthquakes ever recorded shook Japan, creating a devastating tsunami and damaging the Fukushima Dai-ichi nuclear power plant. The accident resulted in the largest unintentional release of radioactivity into the ocean in history.

On the fourth anniversary of the disaster, Woods Hole Oceanographic Institution (WHOI) and the Long Beach, CA-based Aquarium of the Pacific will debut a new program about ocean radioactivity motivated by the Fukushima nuclear accident. The program will be projected daily in the Aquarium’s Ocean Science Center on the National Oceanic and Atmospheric Administration’s (NOAA) Science on a Sphere® and will be made available to more than 100 institutions around the world through NOAA’s SOS Network with a capacity to reach over 50 million combined visitors.

“We wanted to provide some background in this show, on the sources of radioactivity in the oceans prior to, and now across the Pacific, after Fukushima. That perspective is important as we live in a radioactive world, with many sources of both naturally occurring and man-made radioactive materials,” said Dr. Ken Buesseler, senior scientist at WHOI who has been studying ocean radioactivity for more than 30 years and lead scientist on the collaborative museum project. “So the important question is not whether the oceans already contain radioactive materials – they do – but how much more radioactivity did Fukushima add to the ocean.”

Today, residents of the West Coast of the United States are particularly concerned about radiation from Fukushima reaching local shores and associated risks to humans and marine life. Viewing the new program, visitors to the Aquarium will learn more about levels of radioactivity in the ocean and whether significant increases have been measured since Fukushima.

“People want to know if they will be safe swimming or surfing in the Pacific Ocean, eating seafood, and consuming products from Japan. This new show addresses many of the public’s questions about radiation from Fukushima, relying on recent data collected by scientists from WHOI, models of ocean currents and other information,” said Dr. Jerry Schubel, president and CEO, Aquarium of the Pacific.

Schubel will be joined by Buesseler in a live webcast at Aquarium of the Pacific at 10 a.m. (Pacific Time) on March 11 to answer questions from the public about the impacts of Fukushima on the ocean. Questions may be submitted live via Twitter @AquariumPacific or via email to Buesseler will also give a lecture at the Aquarium, which will broadcast live from the Aquarium’s website at 7 p.m. (Pacific Time).

In addition to the live webcast on March 11, Buesseler will give two additional public talks in Southern California in March:

– March 9, 2015, 1:30 p.m., Sumner Auditorium, Scripps Institution of Oceanography, La Jolla, CA.

– March 12, 2015, 12 p.m., Doheny Library, Room 240, UPC, University of Southern California, Los Angeles, CA

The collaboration with Aquarium of the Pacific was funded by a grant to WHOI from the Gordon and Betty Moore Foundation. The Aquarium of the Pacific is a nonprofit dedicated to ocean and environmental education.

Ken Buesseler organized the first international oceanographic expedition to the region following the Fukushima disaster and created, a citizen science sampling effort to collect seawater samples along the West Coast and analyze them in his WHOI lab. The results of his analysis are posted on and accessible to anyone. He is also the director of the WHOI Center for Marine Environmental Radioactivity (CMER).

Original Article And Learn More, WHOI

Fukushima Operator Finds New Source of Radiation Leak into Sea

The damaged Fukushima Daiichi Nuclear Power Station as seen during a sea-water sampling boat journey, 7 November 2013. Captions and Photo source: ©© IAEA Imagebank


The operator of the tsunami-crippled Fukushima nuclear power plant said on Tuesday it had found a pool of highly contaminated water on the roof of a plant building and that it had probably leaked into the sea through a gutter when it rained…

Read Full Article, Reuters

Fukushima Accident Still Ongoing After Three Years: Q&A, IPS News (06-20-2014)

Fukushima Radioactivity Detected Off West Coast

Trinidad beach, 20 miles north of Eureka, Humboldt County, California. The offshore rocks are part of the California Coastal National Monument. Photo source: ©© Gafin Kassim

By © Woods Hole Oceanographic Institution;

Monitoring efforts along the Pacific Coast of the U.S. and Canada have detected the presence of small amounts of radioactivity from the 2011 Fukushima Dai-ichi Nuclear Power Plant accident 100 miles (150 km) due west of Eureka, California. Scientists at the Woods Hole Oceanographic Institution (WHOI) found the trace amounts of telltale radioactive compounds as part of their ongoing monitoring of natural and human sources of radioactivity in the ocean.

In the aftermath of the 2011 tsunami off Japan, the Fukushima Dai-ichi Nuclear Power Plant released cesium-134 and other radioactive elements into the ocean at unprecedented levels. Since then, the radioactive plume has traveled west across the Pacific, propelled largely by ocean currents and being diluted along the way. At their highest near the damaged nuclear power plant in 2011, radioactivity levels peaked at more than 10 million times the levels recently detected near North America.

“We detected cesium-134, a contaminant from Fukushima, off the northern California coast. The levels are only detectable by sophisticated equipment able to discern minute quantities of radioactivity,” said Ken Buesseler, a WHOI marine chemist, who is leading the monitoring effort. “Most people don’t realize that there was already cesium in Pacific waters prior to Fukushima, but only the cesium-137 isotope. Cesium-137 undergoes radioactive decay with a 30-year half-life and was introduced to the environment during atmospheric weapons testing in the 1950s and ’60s. Along with cesium-137, we detected cesium-134 – which also does not occur naturally in the environment and has a half-life of just two years. Therefore the only source of this cesium-134 in the Pacific today is from Fukushima.”

The amount of cesium-134 reported in these new offshore data is less than 2 Becquerels per cubic meter (the number of decay events per second per 260 gallons of water). This Fukushima-derived cesium is far below where one might expect any measurable risk to human health or marine life, according to international health agencies. And it is more than 1000 times lower than acceptable limits in drinking water set by US EPA.

Scientists have used models to predict when and how much cesium-134 from Fukushima would appear off shore of Alaska and the coast of Canada. They forecast that detectable amounts will move south along the coast of North America and eventually back towards Hawaii, but models differ greatly on when and how much would be found.

“We don’t know exactly when the Fukushima isotopes will be detectable closer to shore because the mixing of offshore surface waters and coastal waters is hard to predict. Mixing is hindered by coastal currents and near-shore upwelling of colder deep water,” said Buesseler. “We stand to learn more from samples taken this winter when there is generally less upwelling, and exchange between coastal and offshore waters maybe enhanced.”

Because no U.S. federal agency is currently funding monitoring of ocean radioactivity in coastal waters, Buesseler launched a crowd-funded, citizen-science program to engage the public in gathering samples and to provide up-to-date scientific data on the levels of cesium isotopes along the west coast of North America and Hawaii. Since January 2014, when Buesseler launched the program, individuals and groups have collected more than 50 seawater samples and raised funds to have them analyzed. The results of samples collected from Alaska to San Diego and on the North Shore of Hawaii are posted on the website To date, all of the coastal samples tested in Buesseler’s lab have shown no sign of cesium-134 from Fukushima (all are less than their detection limit of 0.2 Becquerel per cubic meter).

The offshore radioactivity reported this week came from water samples collected and sent to Buesseler’s lab for analysis in August by a group of volunteers on the research vessel Point Sur sailing between Dutch Harbor, Alaska, and Eureka, California. These results confirm prior data described at a scientific meeting in Honolulu in Feb. 2014 by John Smith, a scientist at Fisheries and Oceans Canada in Dartmouth, Nova Scotia, who found similar levels on earlier research cruises off shore of Canada. Buesseler and Smith are now working together on a new project, led by Jay Cullen at the University of Victoria, Canada, called InFORM ( that involves Canadian academic, government and NGO partners to determine and communicate the environmental risks posed by Fukushima for Canada’s Pacific and Arctic coasts and their inhabitants.

Buesseler believes the spread of radioactivity across the Pacific is an evolving situation that demands careful, consistent monitoring of the sort conducted from the Point Sur.

“Crowd-sourced funding continues to be an important way to engage the public and reveal what is going on near the coast. But ocean scientists need to do more work offshore to understand how ocean currents will be transporting cesium on shore. The models predict cesium levels to increase over the next two to three years, but do a poor job describing how much more dilution will take place and where those waters will reach the shore line first,” said Buesseler. “So we need both citizen scientists to keep up the coastal monitoring network, but also research vessels and comprehensive studies offshore like this one, that are too expensive for the average citizen to support,” said Buesseler.

Original Article And Learn More, WHOI