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| Titel |
Direct observation of 134Cs and 137Cs in surface seawater in the western and central North Pacific after the Fukushima Dai-ichi nuclear power plant accident |
| VerfasserIn |
H. Kaeriyama, D. Ambe, Y. Shimizu, K. Fujimoto, T. Ono, S. Yonezaki, Y. Kato, H. Matsunaga, H. Minami, S. Nakatsuka, T. Watanabe |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 6 ; Nr. 10, no. 6 (2013-06-27), S.4287-4295 |
| Datensatznummer |
250018313
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| Publikation (Nr.) |
 copernicus.org/bg-10-4287-2013.pdf |
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| Zusammenfassung |
| The horizontal distribution of radioactive cesium (Cs) derived from the
Fukushima Dai-ichi nuclear power plant (FNPP) in the North Pacific is still
unclear due to the limitation of direct measurement of the seawater in the
open ocean. We present the result of direct observation of radioactive Cs in
surface seawater collected from a broad area in the western and central North
Pacific in July 2011, October 2011 and July 2012. We also conducted a simple
particle tracking experiment to estimate the qualitative spatial
distribution of radioactive Cs in the North Pacific. 134Cs was
detected at 94 stations out of 123 stations, and 137Cs was detected at
all stations. High 134Cs and 137Cs concentrations more than 10 m Bq kg−1
were observed in the area of the northern part of Kuroshio
Extension at 144° E and 155° E in July 2011, in the area
147–175° E around 40° N in October 2011,
and the northern part of Kuroshio Extension at 155° E and
175°30´ E in July 2012. Combining the result of direct
observations and particle tracking experiment, the radioactive Cs derived
from the FNPP had been dispersed eastward to the central North Pacific during
2011. It was considered from the horizontal distribution that radioactive Cs
was dispersed not only eastward but also north- and southward in the central
North Pacific. Pronounced dilution process of radioactive Cs from the FNPP
during study period is suggested from temporal change in the activity ratio
of 134Cs / 137Cs, which was decay-corrected on 6 April 2011, and
relationships between radioactive Cs and temperature. |
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