© Makio Honda, Japan Agency for Marine-Earth Science and Technology

     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…

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