Drifter plot and radioactive substance levels plot relating to Fukushima

BOTTOM: An international scientific team led by WHOI marine chemist Ken Buesseler completed a research cruise in June 2011 to assess the levels and dispersion of radioactive substances from the Fukushima nuclear power plant and their potential impact on marine life. This map shows the sampling stations and cruise track near the Kuroshio Current (shown in yellow and red) Sampling began 400 miles offshore and moved to within 20 miles of the nuclear complex.
TOP: WHOI physical oceanographer Steven Jayne released two dozen surface drifters, which transmitted their locations via satellite while they moved with ocean currents. The color coded track lines from individual drifters, combined with radionuclide data, indicated that the powerful Kuroshio Current acted as both a highway and a barrier, carrying much of the radiation quickly away from shore while also largely preventing it from spreading south.
(Illustration by Steven R. Jayne, © Woods Hole Oceanographic Institution)