동해 남서부 유광대에서 226Ra과 228Ra의 농도 수직 분포

Title
동해 남서부 유광대에서 226Ra과 228Ra의 농도 수직 분포
Alternative Title
Activity profiles of 226Ra and 228Ra in the euphotic zone of southwestern East/Japan Sea
Author(s)
P. Lindahl; M. Eriksson; 김석현; 홍기훈
KIOST Author(s)
Kim, Suk Hyun(김석현)
Publication Year
2017-06-14
Abstract
Distributions of the naturally occurring radionuclides226Ra and 228Ra in the water column were studied at thesouthwestern part of the East/Japan Sea. Activityconcentration depth profiles in the thermocline (depth200 m) of 226Ra and 228Ra were obtained at four stationsalong a transect from 35ºN to 36ºN at 130º50E.The upper 150 m of the southwestern East/Japan Seaconsists of warm and saline water transported by theTsushima Current through the Korea/Tsushima Straitwith about 20 % originating from the continental shelfwaters of the East China Sea and the Yellow Sea withthe remaining 80 % from the Kuroshio Current waters(Nozaki et al., 1989).Radium was extracted from seven depths by pumpingseawater through MnO2-impregnated filters in tandemwith an overall extraction efficiency of 90 ± 6 %. The226Ra and 228Ra activity concentrations were determinedby gamma-ray spectrometry with well-defined geometry.226Ra activity concentrations in the water column showedminor variations in the upper 200 m with an average of1.9 ± 0.3 Bq m-3. The 228Ra activity concentrationsdecreased with depth from ~4 Bq m-3 at the surface to ~1Bq m-3 at depth 100 m reflecting the contribution of theTsushima Current water in the southwestern East/JapanSea.From the 228Ra/226Ra activity ratios in the upper 100 mwater column (Fig. 2), mixing ratios in the seawater atthe sampling site was estimated 228Ra were obtained at four stationsalong a transect from 35ºN to 36ºN at 130º50E.The upper 150 m of the southwestern East/Japan Seaconsists of warm and saline water transported by theTsushima Current through the Korea/Tsushima Straitwith about 20 % originating from the continental shelfwaters of the East China Sea and the Yellow Sea withthe remaining 80 % from the Kuroshio Current waters(Nozaki et al., 1989).Radium was extracted from seven depths by pumpingseawater through MnO2-impregnated filters in tandemwith an overall extraction efficiency of 90 ± 6 %. The226Ra and 228Ra activity concentrations were determinedby gamma-ray spectrometry with well-defined geometry.226Ra activity concentrations in the water column showedminor variations in the upper 200 m with an average of1.9 ± 0.3 Bq m-3. The 228Ra activity concentrationsdecreased with depth from ~4 Bq m-3 at the surface to ~1Bq m-3 at depth 100 m reflecting the contribution of theTsushima Current water in the southwestern East/JapanSea.From the 228Ra/226Ra activity ratios in the upper 100 mwater column (Fig. 2), mixing ratios in the seawater atthe sampling site was estimated
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/23939
Bibliographic Citation
ENVIRA2017, pp.149, 2017
Publisher
J. Environ. Radioact.Ra-226
Type
Conference
Language
English
Publisher
J. Environ. Radioact.Ra-226
Related Researcher
Research Interests

marine pollution management,marine biogeochemistry,marine environmental radioactivity,해양오염관리,해양물질순환,해양환경방사능

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