New North Atlantic Palaeo-Temperature Reconstruction from Terrestrial Sedimentary Archives: Implications for the Influence of the Icelandic Plume on O

根据陆地沉积档案重建新的北大西洋古温度：冰岛羽流对 O 的影响的含义

• 批准号: 2435697
• 金额: --
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2435697
• 关键词: New; North; Atlantic; Palaeo; Temperature

The Icelandic Plume is the most vigorous mantle convection cell currently within Earth's mantle. The Greenland-Scotland Ridge (GSR) is the hotspot track of the Icelandic Plume and forms one of the most important gateways in the global circulation system. Relatively small (c. 100 m) changes in GSR elevation have a strong influence on oceanic circulation. Pulsing behaviour of the Icelandic Plume has driven 100 m-scale changes in GSR elevation on a million-year timeframe throughout Cenozoic time, resulting in variations in oceanic circulation. North Atlantic palaeo-temperature records are required to ask how these circulation changes influence climate. Surprisingly, there is relatively little high quality palaeo-temperature information in the vicinity of the GSR itself. The few available North Atlantic palaeo-temperature reconstructions are predominantly based on marine sedimentary archives, for which temperature proxies are well established. Recent advances in organic geochemistry have developed the use of branched glycerol dialkyl glycerol tetraethers (br-GDGTs) in organic-rich terrestrial sediments as a proxy for air temperature. Such new tools open the possibility of significantly increasing the number of North Atlantic Cenozoic palaeo-temperature records by analysing lignite-bearing sedimentary packages.A pilot study of the thick, Pliocene, lignite-bearing Tjörnes sedimentary succession of northern Iceland shows that original palaeo-temperature information is overprinted, but not destroyed, by burial. Several geographically localised palaeo-temperature calibrations currently exist for br-GDGTs. This project aims to produce a single, widely applicable calibration that accounts for a range of burial conditions by combining lab-based experiments and fieldwork. The new Icelandic Pliocene palaeo-temperature record will then be extended back to the Oligocene using lignites from Northern Ireland, Norway and Greenland, with access aided by project partners. The new Cenozoic palaeotemperature record will be interpreted in the light of an ongoing Birmingham-based General Circulation Model (GCM) study of the effect of GSR elevation on oceanic circulation. This analysis will work alongside and benefit from anticipated IODP drilling in the North Atlantic south of Iceland. Building a more complete understanding of climate change through the Cenozoic will help better predict how anthropogenic climate change might affect the world in the next century.

冰岛地幔柱是目前地球地幔中最活跃的地幔对流圈。格陵兰-苏格兰海脊（GSR）是冰岛羽流的热点路径，是全球环流系统中最重要的门户之一。相对较小（C。100 m）的变化对海洋环流有很强的影响。在整个新生代，冰岛烟羽的脉动行为在百万年的时间范围内驱动了海平面上升速率100米尺度的变化，导致海洋环流的变化。北大西洋的古温度记录需要了解这些环流变化如何影响气候。令人惊讶的是，在海矿资源本身附近几乎没有高质量的古温度信息。现有的少数北大西洋古温度重建主要是基于海洋沉积档案，其中温度代理已建立良好。在有机地球化学的最新进展开发了使用支链甘油二烷基甘油四醚（br-GDGT）在有机丰富的陆地沉积物作为一个代理的空气温度。这些新工具打开了通过分析含褐煤的沉积包来显著增加北大西洋新生代古温度记录数量的可能性。对北方冰岛厚的上新世含褐煤的Tjörnes沉积序列的初步研究表明，原始古温度信息被覆盖，但没有被埋葬破坏。几个地理上局部的古温度校准目前存在的br-GDGT。该项目旨在通过结合实验室实验和实地工作，产生一种单一的、广泛适用的校准，以解释一系列埋葬条件。新的冰岛上新世古温度记录将利用来自北方爱尔兰、挪威和格陵兰的褐煤，在项目合作伙伴的帮助下，追溯到渐新世。新的新生代古温度记录将根据一个正在进行的基于伯明翰的大气环流模式（GCM）研究海平面上升对海洋环流的影响进行解释。这项分析将与冰岛南部北大西洋的IODP钻探一起工作，并从中受益。通过新生代建立对气候变化的更完整的理解将有助于更好地预测下一个世纪人为气候变化可能如何影响世界。