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Titel |
Spatial variability and the fate of cesium in coastal sediments near Fukushima, Japan |
VerfasserIn |
E. E. Black, K. O. Buesseler |
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 ; 11, no. 18 ; Nr. 11, no. 18 (2014-09-23), S.5123-5137 |
Datensatznummer |
250117607
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Publikation (Nr.) |
copernicus.org/bg-11-5123-2014.pdf |
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Zusammenfassung |
Quantifying the amount of cesium incorporated into marine
sediments as a result of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP)
accident has proven challenging due to the limited multi-core sampling from
within the 30 km zone around the facility; the inherent spatial
heterogeneities in ocean sediments; and the potential for inventory
fluctuations due to physical, biological, and chemical processes. Using
210Pb, 234Th, 137Cs, and 134Cs profiles from 20 sediment
cores, coastal sediment inventories were reevaluated. A 137Cs sediment
inventory of 100 ± 50 TBq was found for an area of 55 000 km2
using cores from this study and a total of 130 ± 60 TBq using an
additional 181 samples. These inventories represent less than 1% of the
estimated 15–30 PBq of cesium released during the FDNPP disaster. The time
needed for surface sediment activities (0 to 3 cm) at the 20 locations to be
reduced by 50% via sediment mixing was estimated to range from 0.4 to
26 yr. Due to the observed variability in mixing rates, grain size, and
inventories, additional cores are needed to improve these estimates and
capture the full extent of cesium penetration into the shallow coastal
sediments, which was deeper than 14 cm for all cores retrieved from water
depths less than 150 m. |
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