Cesium 137 transport into the Arctic Ocean through Fram Strait

Abstract

Cesium 134 and 137Cs activities were measured in water samples collected in March–April 1981 at the Fram 3 ice station located 200 km north of Fram Strait. The water depth profiles of these isotopes reveal the presence of two pathways for the entry of anthropogenic tracers into the Arctic Ocean through Fram Strait. Atlantic water passing across the Yermak Plateau at the 100–200 m level is labeled by elevated concentrations of 134Cs and 137Cs associated with inputs from the Sellafield reprocessing plant in the United Kingdom. The 134Cs/137Cs ratio is consistent with a transit time into the Nansen Basin from the Sellafield, United Kingdom, vicinity of 5–6 years. An elevated concentration of 137Cs at the 1500‐m level is associated with inputs of recently ventilated water from the Greenland‐Norwegian seas or as a consequence of brine formation and off‐shelf transport from the Barents Sea.