The application of radiogenic neodymium isotopes as a palaeo water mass tracer in the subpolar North Atlantic
The application of radiogenic neodymium isotopes as a palaeo water mass tracer in the subpolar North Atlantic
复制标题
放射性钕同位素作为北大西洋近极地古水质量示踪剂的应用
DOI：
10.11588/heidok.00023188
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Blaser
中科院分区：
文献类型：
--
作者：
Blaser
北大西洋深层水（NADW）的形成是一个复杂而重要的机制，它将巨大的海洋热量和碳库与高度气候相关的大气库耦合起来。为了研究末次冰消期深水形成的作用，需要海洋沉积物中存档的代用品。一个代用品，以确定当地深沃茨和他们的混合是同位素组成的海水衍生的钕（Nd IC）。然而，准确的解释这个代理，需要很好的知识的Nd IC的水团端成员。本文对Nd在深海沉积物中的分布、反应性和迁移性进行了详细的研究。这项调查的证据一般不动的Nd在沉积物中，并导致现有的方法的完善，从不同组成的散装沉积物中提取的自生Nd IC。随后重建的深水钕IC横跨亚极地北大西洋允许的NADW和它携带的Nd IC的形成的变化的调查。结果表明，第一个直接的证据表明，一个突出的瞬态Nd IC变化的深NADW在全新世起源于其源沃茨，可能在北欧海。
The formation of North Atlantic Deep Water (NADW) is a complex and important mechanism coupling the large oceanic reservoir of heat and carbon to the highly climate relevant atmospheric reservoir. In order to study the role of deep water formation during the last deglaciation, proxies archived in marine sediments are required. One proxy for the identification of local deep waters and their mixing is the isotope composition of seawater-derived Nd (Nd IC). An accurate interpretation of this proxy, however, requires good knowledge of the Nd ICs of water mass end members. In this thesis the distribution, reactivity, and mobility of Nd in deep sea sediments was assessed in detail. This investigation evidences a general immobility of Nd in sediments and results in a refinement of existing methods for the extraction of an authigenic Nd IC from bulk sediments of varying compositions. The subsequent reconstruction of deep water Nd ICs across the subpolar North Atlantic allows for the investigation of changes in the formation of NADW and the Nd IC it carries. The results show the first direct evidence that a prominent transient Nd IC change of deep NADW during the Holocene originated in its source waters, probably in the Nordic Seas.