Fractionation of Ra-226 and Ba in the Upper North Pacific Ocean

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A90107%2F22%3A00363781" target="_blank" >RIV/68407700:90107/22:00363781 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.3389/fmars.2022.859117" target="_blank" >https://doi.org/10.3389/fmars.2022.859117</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3389/fmars.2022.859117" target="_blank" >10.3389/fmars.2022.859117</a>

Result language

angličtina

Original language name

Fractionation of Ra-226 and Ba in the Upper North Pacific Ocean

Original language description

Investigations conducted during the GEOSECS program concluded that radium-226 (T-1/2 = 1602 y) and barium are tightly correlated in waters above 2500 m in the Atlantic, Pacific and Antarctic Oceans, with a fairly uniform Ra-226/Ba ratio of 2.3 +/- 0.2 dpm mu mol(-1) (4.6 nmol Ra-226/mol Ba). Here, we report new Ra-226 and Ba data obtained at three different stations in the Pacific Ocean: stations K1 and K3 in the North-West Pacific and station old Hale Aloha, off Hawaii Island. The relationship between Ra-226 and Ba found at these stations is broadly consistent with that reported during the GEOSECS program. At the three investigated stations, however, we find that the Ra-226/Ba ratios are significantly lower in the upper 500 m of the water column than at greater depths, a pattern that was overlooked during the GEOSECS program, either because of the precision of the measurements or because of the relatively low sampling resolution in the upper 500 m. Although not always apparent in individual GEOSECS profiles, this trend was noted before from the non-zero intercept of the linear regression when plotting the global data set of Ba versus Ra-226 seawater concentration and was attributed, at least in part, to the predominance of surface input from rivers for Ba versus bottom input from sediments for Ra-226. Similarly, low Ra-226/Ba ratios in the upper 500 m have been reported in other oceanic basins (e.g. Atlantic Ocean). Parallel to the low Ra-226/Ba ratios in seawater, higher Ra-226/Ba ratios were found in suspended particles collected in the upper 500 m. This suggests that fractionation between the two elements may contribute to the lower Ra-226/Ba ratios found in the upper 500 m, with Ra-226 being preferentially removed from surface water, possibly as a result of mass fractionation during celestite formation by acantharians and/or barite precipitation, since both chemical elements have similar ionic radius and the same configuration of valence electrons. This finding

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10505 - Geology

Project

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Continuities

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Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Frontiers in Marine Science

ISSN

2296-7745

e-ISSN

2296-7745

Volume of the periodical

9

Issue of the periodical within the volume

859117

Country of publishing house

CH - SWITZERLAND

Number of pages

15

Pages from-to

1-15

UT code for WoS article

000834261600001

EID of the result in the Scopus database

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