Wireline tap on the construction of the North Atlantic Deep water - IODP Exp. 395 "Reykjanes Mantle Convection and Climate"

北大西洋深水建设中的有线接入 - IODP Exp.

• 批准号: NE/W002310/1
• 负责人: Sarah Davies
• 金额: $ 2.97万
• 依托单位: University of Leicester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW002310%2F1
• 关键词: Wireline; tap; construction; North; Atlantic

Ocean circulation patterns especially within the deep ocean are a major player in global heat exchange and therefore force and stabilize climate patterns. In the North Atlantic, deep water masses are influenced by two main factors changing deep water strength and composition over time, the potential of water exchange with the Arctic Ocean and the development of the Northern hemisphere glaciation. The overflow across the Greenland-Iceland-Scotland Ridge, one of only two areas, where Arctic Ocean waters are exchanged with the world's oceans, can be shut off by the periodically strong pulsation of the Iceland mantle plume or in more recent times by glaciation of the Northern Seas and its surrounding land masses. In such an event, deep water circulation within the North Atlantic slows significantly, leading among other effects to a colder and more unstable climate in Western Europe.In this project, we propose to reconstruct the past behavior of deep water currents within the North Atlantic, by analyzing downhole logging data collected during IODP Expedition 395 "Reykjanes Ridge Mantle Convection and Climate". The drill sites are located in a transect along 60N, which represent a millennial scale archive of deep ocean sedimentation and current behavior ranging up to 12 Ma in the past to the Miocene. Downhole logging data will be collected after coring and has the advantages of being an in-situ continuous measurement through the strata, bridging potential gaps in core recovery. Recent experiments to measure current strength within the Atlantic has revealed, a decline in current strength in the recent past making the current circulation the weakest in the last millennia. Years of especially weak Atlantic currents correlate with an increase in weather events such as storms and floods within the British Isles and the rest of Western Europe. Understanding the past behavior of deep ocean circulation will therefore allow us to inform climate models used to predict severe weather events and use these predictions to minimize their impacts.

海洋环流模式，特别是深海内的环流模式，是全球热交换的主要参与者，因此影响和稳定气候模式。在北大西洋，深海水团受到两个主要因素的影响，这两个因素随着时间的推移改变着深海水的强度和组成，即与北冰洋进行水交换的潜力和北方冰川作用的发展。格陵兰-冰岛-苏格兰海脊是北冰洋沃茨与世界海洋交换的仅有的两个地区之一，其溢流可以被冰岛地幔柱的周期性强烈脉动或在更近的时期被北方海及其周围陆地的冰川作用所阻断。在这种情况下，北大西洋的深水环流显着放缓，导致在其他影响更冷，更不稳定的气候在西欧。在这个项目中，我们建议重建过去的行为在北大西洋的深水电流，通过分析在IODP远征395“雷克雅未克岭地幔对流和气候”期间收集的井下测井数据。钻探地点位于沿着60 N的一个断面上，代表了从过去到中新世长达12 Ma的深海沉积和海流行为的千年尺度档案。井下测井数据将在取芯后收集，其优点是可在地层中进行现场连续测量，弥补取芯过程中的潜在缺口。最近测量大西洋内海流强度的实验显示，最近的海流强度下降，使海流环流成为过去一千年来最弱的。大西洋洋流特别弱的年份与不列颠群岛和西欧其他地区的风暴和洪水等天气事件的增加有关。因此，了解深海环流过去的行为将使我们能够为用于预测恶劣天气事件的气候模型提供信息，并利用这些预测来最大限度地减少其影响。

项目成果

Expedition 395C Preliminary Report: Reykjanes Mantle Convection and Climate: Crustal Objectives

395C 探险队初步报告：雷克雅内斯地幔对流和气候：地壳目标

• DOI: 10.14379/iodp.pr.395c.2022
• 发表时间: 2022
• 作者: Parnell-Turner R