Krypton-85 in the Ocean
Abstract A method is described to determine for the first time the 85 Kr concentration in seawater. Samples of 220 l of seawater are degassed aboard a research vessel. The krypton contained in the gas sample is isolated in the laboratory and its 8s Kr activity is measured in a gas counter. The backg...
Published in: | Zeitschrift für Naturforschung A |
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Walter de Gruyter GmbH
1975
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crdegruyter:10.1515/zna-1975-0807 2024-09-15T18:23:48+00:00 Krypton-85 in the Ocean Schröder, Jörg 1975 http://dx.doi.org/10.1515/zna-1975-0807 https://www.degruyter.com/view/journals/zna/30/8/article-p962.xml https://www.degruyter.com/document/doi/10.1515/zna-1975-0807/xml https://www.degruyter.com/document/doi/10.1515/zna-1975-0807/pdf en eng Walter de Gruyter GmbH http://creativecommons.org/licenses/by-nc-nd/3.0/ Zeitschrift für Naturforschung A volume 30, issue 8, page 962-967 ISSN 1865-7109 0932-0784 journal-article 1975 crdegruyter https://doi.org/10.1515/zna-1975-0807 2024-08-26T04:09:47Z Abstract A method is described to determine for the first time the 85 Kr concentration in seawater. Samples of 220 l of seawater are degassed aboard a research vessel. The krypton contained in the gas sample is isolated in the laboratory and its 8s Kr activity is measured in a gas counter. The background of the lowel-level counting-array is 0.026 cpm; surface water samples yield a netto count-rate of 0.13 cpm. The reproducibility of the method was checked by gas standards (krypton-air mixtures) and moreover by three surface water samples; both sets agree within ± 1 σ, or ± 5%. The mean value of three samples of great depths (1600, 2000, 2000 m) is 5% of the surface water concentration. This figure represents the possible contamination of the samples by atmospheric 85 Kr during the various preparation stages (blank value). Two profiles have been measured from the North Atlantic (about 40°N, 18°W, November 1972). A strong decrease of the 85 Kr concentration is found in the upper 1000 m. In a simple one-dimensional vertical diffusion-advection model the profiles can be simulated with a coefficient of apparent vertical eddy diffusion of 5 cm 2 / sec in the depth range of 300 to 1000 m (main thermocline). A possible application of oceanic 85 Kr data is the combination of depth profiles with those of other tracers, in particular 3 H. Another application of the 85 Kr method is the dating of groundwaters younger than 20 years. Article in Journal/Newspaper North Atlantic De Gruyter Zeitschrift für Naturforschung A 30 8 962 967 |
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Open Polar |
collection |
De Gruyter |
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crdegruyter |
language |
English |
description |
Abstract A method is described to determine for the first time the 85 Kr concentration in seawater. Samples of 220 l of seawater are degassed aboard a research vessel. The krypton contained in the gas sample is isolated in the laboratory and its 8s Kr activity is measured in a gas counter. The background of the lowel-level counting-array is 0.026 cpm; surface water samples yield a netto count-rate of 0.13 cpm. The reproducibility of the method was checked by gas standards (krypton-air mixtures) and moreover by three surface water samples; both sets agree within ± 1 σ, or ± 5%. The mean value of three samples of great depths (1600, 2000, 2000 m) is 5% of the surface water concentration. This figure represents the possible contamination of the samples by atmospheric 85 Kr during the various preparation stages (blank value). Two profiles have been measured from the North Atlantic (about 40°N, 18°W, November 1972). A strong decrease of the 85 Kr concentration is found in the upper 1000 m. In a simple one-dimensional vertical diffusion-advection model the profiles can be simulated with a coefficient of apparent vertical eddy diffusion of 5 cm 2 / sec in the depth range of 300 to 1000 m (main thermocline). A possible application of oceanic 85 Kr data is the combination of depth profiles with those of other tracers, in particular 3 H. Another application of the 85 Kr method is the dating of groundwaters younger than 20 years. |
format |
Article in Journal/Newspaper |
author |
Schröder, Jörg |
spellingShingle |
Schröder, Jörg Krypton-85 in the Ocean |
author_facet |
Schröder, Jörg |
author_sort |
Schröder, Jörg |
title |
Krypton-85 in the Ocean |
title_short |
Krypton-85 in the Ocean |
title_full |
Krypton-85 in the Ocean |
title_fullStr |
Krypton-85 in the Ocean |
title_full_unstemmed |
Krypton-85 in the Ocean |
title_sort |
krypton-85 in the ocean |
publisher |
Walter de Gruyter GmbH |
publishDate |
1975 |
url |
http://dx.doi.org/10.1515/zna-1975-0807 https://www.degruyter.com/view/journals/zna/30/8/article-p962.xml https://www.degruyter.com/document/doi/10.1515/zna-1975-0807/xml https://www.degruyter.com/document/doi/10.1515/zna-1975-0807/pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Zeitschrift für Naturforschung A volume 30, issue 8, page 962-967 ISSN 1865-7109 0932-0784 |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/3.0/ |
op_doi |
https://doi.org/10.1515/zna-1975-0807 |
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Zeitschrift für Naturforschung A |
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30 |
container_issue |
8 |
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962 |
op_container_end_page |
967 |
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1810464070464176128 |