The distribution of 227Ac along the GA01 section in the North Atlantic
The distribution of 227Ac along the GA01 section in the North Atlantic
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北大西洋 GA01 断面 227Ac 分布
DOI：
10.1016/j.marchem.2023.104207
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发表时间：
2023
期刊：
影响因子：
3
通讯作者：
Deng, Feifei
中科院分区：
文献类型：
--
作者：
Le Roy, Emilie;van Beek, Pieter;Lacan, François;Souhaut, Marc;Sanial, Virginie;Charette, Matthew A.;Henderson, Paul B.;Deng, Feifei
锕-227是研究海洋垂直混合的有力工具，最近被提议作为热液羽流的示踪剂。然而，由于227 Ac活动在海洋中特别低，迄今为止进行的研究相对较少，并且没有进行大规模的研究，如本研究报告所述。在这里，我们报告了一段溶解227 Ac在葡萄牙-格陵兰岛-加拿大之间的北大西洋的基础上，在国际GEOTRACES计划（GA 01部分- GEOVIDE巡航，2014年5月至7月）的框架内获得的九个全深度剖面。同时测定了227 Ac的母核231 Pa，使我们能够报告一个过量227 Ac活动（227 Acex）的剖面。与其他海洋盆地相比，该剖面的锕-227活动特别低（<0.4 dpm m−3）。在大多数情况下，227 Ac活动在500 m以上的水柱中达到长期平衡，231 Pa。长期平衡被认为是在子体的35个半衰期后达到的。因此，长期均衡表明，在过去的100年里没有外部投入。最高的227 Ac活动经常被发现接近海底，表明227 Ac扩散出沉积物。然而，两种不同的模式的问题，传统的一维垂直混合模型通常适用于227 Ac释放的深海沉积物：第一，显着的227 Ac被发现在上500米的水柱在几个站位于伊比利亚边缘附近。在上500米，高227 Acexactivities可能表明横向平流的沃茨与边缘相互作用。第二，沿沿着偶尔观察到227 Acex的中水峰。在Irminger盆地的44号站，2500米处的227 Ac活性峰值与高溶解铁浓度共存，可以解释为热液羽流的特征。在海底附近，我们经常观察到底部云状层，我们不能排除这些层影响227 Ac分布。
Actinium-227 is a powerful tool to study vertical mixing in the ocean, and was more recently proposed as a tracer of hydrothermal plumes. However, because227Ac activities are especially low in the ocean, relatively few studies have been conducted to date, and none has been done on the large scale, as is reported in the present study. Here, we report a section of dissolved227Ac in the North Atlantic Ocean between Portugal-Greenland-Canada based on nine full-depth profiles obtained in the framework of the international GEOTRACES program (GA01 section - GEOVIDE cruise, May–July 2014). The simultaneous determination of231Pa, the parent nuclide of227Ac, along the section allowed us to report a section of excess227Ac activities (227Acex).Actinium-227 activities were especially low along the section (<0.4 dpm m−3) compared to other ocean basins. In most cases,227Ac activities reached secular equilibrium with231Pa in the water column 500 m above the seafloor. Secular equilibrium is considered reached after ∼five half-lives of the daughter. Secular equilibrium therefore suggests no external input over the last ∼100 years. The highest227Ac activities were often found close to the seafloor, indicating that227Ac diffuses out of the sediments. However, two different patterns question the traditional one-dimensional vertical mixing model typically applied to227Ac released by deep-sea sediments: first, significant227Acexwere found in the upper 500 m of the water column at several stations located near the Iberian margin. In the upper 500 m, the high227Acexactivities could indicate lateral advection of waters that interacted with the margins. Second, mid-water peaks of227Acexwere occasionally observed along the transect. At station 44 in the Irminger Basin, a peak of227Acexactivity at 2500 m that was co-located with high dissolved Fe concentrations could be interpreted as the signature of a hydrothermal plume. Near the seafloor, we often observed bottom nepheloid layers and we cannot exclude that these layers impact the227Ac distributions.
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北大西洋和拉布拉多海沿 GEOVIDE 剖面的溶解铁（GEOTRACES 剖面 GA01）
影响因子：
4.9
作者：
Manon Tonnard;H. Planquette;A. Bowie;P. van der Merwe;M. Gallinari;Floriane Desprez de Gésincourt;Y. Germain;Arthur Gourain;M. Benetti;G. Reverdin;P. Tréguer;Julia Boutorh;M. Cheize;F. Lacan;Jan‐Lukas Menzel Barraqueta;Leonardo Pereira;R. Shelley;P. Lherminier;G. Sarthou
通讯作者：
G. Sarthou
影响因子：
3.4
作者：
I. Yashayaev;B. Dickson
通讯作者：
B. Dickson
热液喷口：以前未被认识的深海锕227来源
影响因子：
3
作者：
L. Kipp;M. Charette;D. Hammond;W. Moore
通讯作者：
W. Moore
锕-227 的海洋地球化学：其通过沉积物孔隙水迁移的证据
影响因子：
5.2
作者：
Y. Nozaki;M. Yamada;Hirofumi Nikaido
通讯作者：
Hirofumi Nikaido
DOI：
10.1016/s0399-1784(98)80031-5
发表时间：
1998-05-01
期刊：
OCEANOLOGICA ACTA
影响因子：
--
作者：
Nozaki, Y;Yamada, M;Tsubota, H
通讯作者：
Tsubota, H