Vertical distribution of 236U in the North Pacific Ocean

被引:27
作者
Eigl, R. [1 ]
Steier, Peter [2 ]
Sakata, K. [1 ]
Sakaguchi, A. [3 ]
机构
[1] Hiroshima Univ, Grad Sch Sci, Dept Earth & Planetary Syst Sci, 1-3-1 Kagamiyama,, Higashihiroshima, Hiroshima 7398526, Japan
[2] Univ Vienna, VERA Lab, Fac Phys Isotope Res, Wahringer Str 17, A-1090 Vienna, Austria
[3] Univ Tsukuba, Ctr Res Isotopes & Environm Dynam, 1-1-1 Tennodai, Tsukuba, Ibaraki 3058577, Japan
关键词
ANTHROPOGENIC U-236; INDIAN OCEANS; JAPAN SEA; 1ST; FUKUSHIMA; WATERS; CS-137; AMS; PU-239; PU-240; RADIONUCLIDES;
D O I
10.1016/j.jenvrad.2016.12.010
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
The first extensive study on U-236 in the North Pacific Ocean has been conducted. The vertical distribution of U-236/U-238 isotopic ratios and the U-236 concentrations were analysed on seven depth profiles, and large variations with depth were found. The range of U-236/U-238 isotopic ratios was from (0.09 +/- 0.03) x 10(-10) to (14.1 +/- 2.2) x 10(-10), which corresponds to U-236 concentrations of (0.69 +/- 0.24) x 10(5) atoms/kg and (119 +/- 21) x 10(5) atoms/kg, respectively. The variations in U-236 concentrations could mainly be attributed to the different water masses in the North Pacific Ocean and their formation processes. Uranium -236 inventories on the water column of each sampling station were calculated and varied between (3.89 +/- 0.08) x 1012 atoms/m2 and (7.03 +/- 0.50) x 10(12) atoms/m(2), which is lower than in former studies on comparable latitudes in the North Atlantic Ocean and the Sea of Japan. The low inventories of U-236 found for the North Pacific Ocean in this study can be explained by the lack of additional input sources of artificial radionuclides, apart from global and regional/local fallout. This study expands the use of U-236 as oceanographic circulation tracer to yet another ocean basin and shows that this isotope can be used for tracing circulation patterns of water masses in the Pacific Ocean. (C) 2016 Elsevier Ltd. All rights reserved.
引用
收藏
页码:70 / 78
页数:9
相关论文
共 42 条
[1]   TC-99 AND CESIUM-134 AS LONG-DISTANCE TRACERS IN ARCTIC WATERS [J].
AARKROG, A ;
BOELSKIFTE, S ;
DAHLGAARD, H ;
DUNIEC, S ;
HALLSTADIUS, L ;
HOLM, E ;
SMITH, JN .
ESTUARINE COASTAL AND SHELF SCIENCE, 1987, 24 (05) :637-647
[2]   CONCENTRATION, VERTICAL FLUX, AND REMINERALIZATION OF PARTICULATE URANIUM IN SEA-WATER [J].
ANDERSON, RF .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1982, 46 (07) :1293-1299
[3]   Temporal variation of 137Cs water column inventory in the North Pacific since the 1960s [J].
Aoyama, A ;
Hirose, K .
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY, 2003, 69 (1-2) :107-117
[4]   Re-construction and updating our understanding on the global weapons tests 137Cs fallout [J].
Aoyama, M ;
Hirose, K ;
Igarashi, Y .
JOURNAL OF ENVIRONMENTAL MONITORING, 2006, 8 (04) :431-438
[5]   Water masses labeled with global fallout 137Cs formed by subduction in the North Pacific [J].
Aoyama, Michio ;
Hirose, Katsumi ;
Nemoto, Kazuhiro ;
Takatsuki, Yasushi ;
Tsumune, Daisuke .
GEOPHYSICAL RESEARCH LETTERS, 2008, 35 (01)
[6]   FALLOUT RADIONUCLIDES IN THE PACIFIC-OCEAN - VERTICAL AND HORIZONTAL DISTRIBUTIONS, LARGELY FROM GEOSECS STATIONS [J].
BOWEN, VT ;
NOSHKIN, VE ;
LIVINGSTON, HD ;
VOLCHOK, HL .
EARTH AND PLANETARY SCIENCE LETTERS, 1980, 49 (02) :411-434
[7]   Fukushima and Ocean Radioactivity [J].
Buesseler, Ken O. .
OCEANOGRAPHY, 2014, 27 (01) :92-105
[8]   First 236U data from the Arctic Ocean and use of 236U/238U and 129I/236U as a new dual tracer [J].
Casacuberta, N. ;
Masque, P. ;
Henderson, G. ;
van-der-Loeff, M. Rutgers ;
Bauch, D. ;
Vockenhuber, C. ;
Daraoui, A. ;
Walther, C. ;
Synal, H. -A. ;
Christl, M. .
EARTH AND PLANETARY SCIENCE LETTERS, 2016, 440 :127-134
[9]   A first transect of 236U in the North Atlantic Ocean [J].
Casacuberta, N. ;
Christl, M. ;
Lachner, J. ;
van der Loeff, M. Rutgers ;
Masque, P. ;
Synal, H. -A. .
GEOCHIMICA ET COSMOCHIMICA ACTA, 2014, 133 :34-46
[10]  
CHEN C T A, 1988, Pacific Science, V42, P237