Publikationen

Reconstruction of the temporal distribution of U-236/U-238 in the Northwest Pacific Ocean using a coral core sample from the Kuroshio Current area

Autor(en)
Tomoya Nomura, Aya Sakaguchi, Peter Steier, Rosmarie Eigl, Akane Yamakawa, Takaaki Watanabe, Keiichi Sasaki, Tsuyoshi Watanabe, Robin Golser, Yoshio Takahashi, Hiroya Yamano
Abstrakt

The temporal distribution of U-236 in the Northwest Pacific Ocean was reconstructed through measurements of the annual changes in U-236/U-238 atom ratios in a coral core collected from Kume Island located within the Kuroshio Current region. In total, 74 years (1940-2014) of temporal trend of U-236/U-238 atom ratios were reconstructed using Accelerator Mass Spectrometry (AMS). The annually resolved U-236/U-238 ratios showed a strong increase from 1952, and two prominent peaks were found in the annual bands for 1954 (11.0 +/- 1.2 x 10(-9)) and 1958 (8.55 +/- 1.17 x 10(-9)); also an enhanced peak was observed for the band of 1963 (3.51 +/- 0.20 x 10(-9)). These peaks coincided with the occurrence of large nuclear tests in the Pacific Proving Grounds and/or the highest global fallout rate, suggesting a clear influence of these nuclear events on U-236/U-238 atom ratios. Furthermore, the coral results showed some disagreement with the annual changes for U-236 in East Asian corals collected at the entrance to the Sea of Japan. Based on these results, the mixing ratios of the surface seawater currents in the Northwest Pacific Ocean have been estimated.

Organisation(en)
Isotopenphysik
Externe Organisation(en)
Hiroshima University, University of Tsukuba, Natl Inst Environm Studies, National Institute for Environmental Studies - Japan, Environm Biol & Ecosyst Studies, Hokkaido University, Kanazawa Gakuin University, University of Tokyo
Journal
Marine Chemistry
Band
190
Seiten
28-34
Anzahl der Seiten
7
ISSN
0304-4203
DOI
https://doi.org/10.1016/j.marchem.2016.12.008
Publikationsdatum
03-2017
Peer-reviewed
Ja
ÖFOS 2012
103014 Kernphysik, 105904 Umweltforschung, 105306 Ozeanographie
Schlagwörter
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/reconstruction-of-the-temporal-distribution-of-u236u238-in-the-northwest-pacific-ocean-using-a-coral-core-sample-from-the-kuroshio-current-area(f469b653-2d1f-4f74-8ebc-f349b667040b).html