کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6430630 | 1634804 | 2012 | 6 صفحه PDF | دانلود رایگان |

We present a feasibility study for using 236U as an oceanic circulation tracer based on depth profiles of 236U and 137Cs in the Japan/East Sea. The concentration of the predominantly anthropogenic 236U, measured with Accelerator Mass Spectrometry (AMS), decreased from (13±3)Ã106 atom/kg in surface water to (1.6±0.3)Ã106 atom/kg close to the sea floor (2800 m). The profile has a smooth trend with depth and concentration values are generally proportional to that of 137Cs for the same water samples, but with a slightly lower ratio of 137Cs/236U below 2000 m. The cumulative inventory of dissolved 236U in the water column was estimated to be (13.7±0.9)Ã1012 atom/m2, which is similar to the global-fallout level (17.8Ã1012 atom/m2) in Japan. Additional analyses of suspended solids (SS) and bottom sediments yielded negligible amounts of 236U. Our results suggest that 236U behaves as a conservative nuclide in seawater, with potential advantages over other tracers of oceanic circulation.
⺠We present a first study using 236U as a new oceanic circulation tracer. ⺠We could measure anthropogenic global-fallout 236U in sea water and sea sediments. ⺠Depth profile of 236U was nearly proportional to that of 137Cs observed in the same water samples. ⺠236U behaves conservative in seawater.
Journal: Earth and Planetary Science Letters - Volumes 333â334, 1 June 2012, Pages 165-170