Origin of Abyssal NW Atlantic Water Masses Since the Last Glacial Maximum
Origin of Abyssal NW Atlantic Water Masses Since the Last Glacial Maximum
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自末次盛冰期以来大西洋西北深海水团的起源
DOI：
10.1029/2017pa003290
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发表时间：
2018
影响因子：
3.5
通讯作者：
J. Lippold
中科院分区：
文献类型：
--
作者：
Pöppelmeier;M. Gutjahr;P. Blaser;L. D. Keigwin;J. Lippold
浅北源中间水团的概念是末次盛冰期大西洋环流方案的一个充分证明的特征。然而，最近在西北大西洋深处角隆起的稳定碳同位素（δ13C）观测表明，北分量水团对西北大西洋深海盆地的贡献很大，这是以前没有描述过的。在这里，我们通过测量来自5,010 m水深的相同沉积物的自生钕（Nd）同位素组成，验证了这一来自北部的水团位于南部冰川南极底水之下的假设。钕同位素作为一种半保留的水团示踪剂，能够区分西北大西洋的南北组成水域。我们新的Nd同位素记录解决了从LGM到全新世早期的各种水团变化，与现有的横跨西大西洋的Nd - based重建一致。尤其明显的是新仙女木期和Bølling‐Allerød期，它们的Nd同位素组成发生了前所未有的变化。对于LGM，我们发现了Nd同位素证据，表明北部来源的水团有助于深海深度，因此与先前角隆起的δ13C数据一致。然而，总的来说，西北大西洋深处仍然以南方来源的水为主，因为我们发现了介于南北端成员组成之间的特征。此外，这一新记录表明，C和Nd同位素在一定程度上解耦，表明在LGM期间，两种水质量指标中有一种或多种可能的非保守行为。
The notion of a shallow northern sourced intermediate water mass is a well evidenced feature of the Atlantic circulation scheme of the Last Glacial Maximum (LGM). However, recent observations from stable carbon isotopes (δ13C) at the Corner Rise in the deep northwest Atlantic suggested a significant contribution of a Northern Component Water mass to the abyssal northwest Atlantic basin that has not been described before. Here we test the hypothesis of this northern sourced water mass underlying the southern sourced glacial Antarctic Bottom Water by measuring the authigenic neodymium (Nd) isotopic composition from the same sediments from 5,010‐m water depth. Neodymium isotopes act as a semiconservative water mass tracer capable of distinguishing between Northern and Southern Component Waters at the northwest Atlantic. Our new Nd isotopic record resolves various water mass changes from the LGM to the early Holocene in agreement with existing Nd‐based reconstructions from across the west Atlantic Ocean. Especially pronounced are the Younger Dryas and Bølling‐Allerød with unprecedented changes in the Nd isotopic composition. For the LGM we found Nd isotopic evidence for a northern sourced water mass contributing to abyssal depths, thus being in agreement with previous δ13C data from Corner Rise. Overall, however, the deep northwest Atlantic was still dominated by southern sourced water, since we found signatures that are intermediate between northern and southern end member compositions. Furthermore, this new record indicates that C and Nd isotopes were partly decoupled, pointing to nonconservative behavior of one or more likely of both water mass proxies during the LGM.
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影响因子：
5.3
作者：
T. Stichel;M. Frank;J. Rickli;B. Haley
通讯作者：
T. Stichel;M. Frank;J. Rickli;B. Haley
DOI：
--
发表时间：
1989
期刊：
影响因子：
--
作者：
L. Keigwin;E. Boyle
通讯作者：
E. Boyle
影响因子：
5
作者：
M. Lambelet;T. Flierdt;K. Crocket;M. Rehkämper;K. Kreissig;B. Coles;M. Rijkenberg;L. Gerringa
通讯作者：
M. Lambelet;T. Flierdt;K. Crocket;M. Rehkämper;K. Kreissig;B. Coles;M. Rijkenberg;L. Gerringa
影响因子：
5.3
作者：
F. Kurzweil;M. Gutjahr;D. Vance;L. Keigwin
通讯作者：
F. Kurzweil;M. Gutjahr;D. Vance;L. Keigwin
影响因子：
2.2
作者：
C. Millo;M. Sarnthein;A. Voelker;H. Erlenkeuser
通讯作者：
H. Erlenkeuser