Late Pleistocene desiccation of Lake Tana, source of the Blue Nile.

更新世晚期，青尼罗河源头塔纳湖干涸。

• 批准号: NE/D012996/1
• 负责人: Henry Lamb
• 金额: $ 43.53万
• 依托单位: Aberystwyth University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FD012996%2F1
• 关键词: Late; Pleistocene; desiccation; Lake; Tana

Lake Tana, in the highlands of northern Ethiopia, is the source of the Blue Nile, one of the world's great rivers. Surprisingly, very little is known about the age and history of this lake: one estimate from the 1930's is that it was formed 10,000 years ago by a lava dam. Similarly, little is known about the climatic history of the wider region that comprises the Blue Nile headwaters, despite the fact that the Nile has long been recognized as critical to the resources of ancient and modern Egypt. New geophysical and core data, obtained by us in October 2003 and September 2004 with NERC support, show that the lake may be at least 40,000 years old. Our new data also show that the lake dried out at around 16,000 years ago, and almost certainly at apparently regular intervals during the later stages of the last Ice Age. It is possible that the lake dried because of intense droughts lasting one or two hundred years, and that the droughts were caused by disruption of Africa's monsoon climate when iceberg-laden meltwater from North America flooded the North Atlantic - the Heinrich events. In this new PalaeoTana Project, we aim to test these hypotheses by drilling a sediment core, up to 100m in length, from the northern basin of Lake Tana, in about 10m water depth, and about 2km from shore. The core will be scanned at high resolution using X-ray fluorescence, X-ray and colour imagery, geophysical and magnetic core-scanning technology, without damaging the sedimentary components. The resulting datasets will identify past desiccation events, which will be investigated in detail and interpreted by comparison to sediments of the known drying-out event at 16,000 years ago. Dating the sediments by appropriate methods including luminescence, tephrochronology, and Argon-Argon dating will allow precise estimates of the timing and duration of the drought events. The relative timing of these events in comparison with abrupt climatic events in ocean cores (especially Heinrich events), and in other continental records, will allow inferences about the global- scale mechanisms of abrupt climate change. The data can also be used to test climate models, and thus to help judge the accuracy of model-predicted abrupt climate change in the future. A long core record of past climate and environment from this part of Africa would have major significance for understanding both regional environmental change, because of the influence of the Nile on NE Africa and the eastern Mediterranean, and global climate. It will contribute to understanding how future changes in ocean temperature and circulation will affect global climate, especially in the heavily populated monsoon regions of Africa and Asia. It will also have significance for understanding the later stages of human evolution in and dispersal out of Africa, by providing a record of the environmental changes that influenced early human populations and their water, plant and hunting resources.

塔娜湖（Lake Tana）位于埃塞俄比亚北部的高地，是蓝尼罗河（Blue Nile）的来源，这是世界上伟大的河流之一。令人惊讶的是，关于这个湖泊的年龄和历史知之甚少：1930年代的一个估计是，它是由熔岩大坝在10，000年前形成的。同样，尽管尼罗河长期以来一直被认为是古代和现代埃及的资源至关重要的事实，但对整个地区的气候历史知之甚少。我们于2003年10月和2004年9月获得NERC支持的新的地球物理和核心数据表明，该湖泊可能至少已有40，000年的历史。我们的新数据还表明，该湖在大约16，000年前干燥，几乎可以肯定的是在上一个冰河时代的后期显然是定期的。湖泊可能由于持续一到两百年而干燥的湖泊可能干燥，而干旱是由于非洲季风气候的破坏而导致的，当时北美冰山充满冰山的融合水淹没了北大西洋 - 海因里希事件。在这个新的Palaeotana项目中，我们旨在通过钻高塔娜湖北部盆地的沉积物芯长约100m，大约1000万水深度，距离海岸约2公里，旨在测试这些假设。核心将使用X射线荧光，X射线和颜色图像，地球物理和磁芯扫描技术在高分辨率下进行扫描，而不会损害沉积物组件。由此产生的数据集将确定过去的干燥事件，该事件将进行详细研究，并通过与16，000年前已知的干燥事件的沉积物进行比较来解释。通过适当的方法（包括发光，tephroencology和Argon-Argon年代）来约会沉积物，将允许对干旱事件的时机和持续时间进行精确估计。与海洋核心（尤其是海因里希事件）的突然气候事件以及在其他大陆记录中的突然气候事件相比，这些事件的相对时机将允许推断出突然的气候变化的全球规模机制。数据还可以用于测试气候模型，从而有助于判断未来模型预测的突然气候变化的准确性。由于尼罗河对非洲NE非洲和地中海东部和全球气候的影响，非洲这一地区过去气候和环境的长期核心记录对于理解区域环境变化具有重要意义。它将有助于了解海洋温度和循环的未来变化将如何影响全球气候，尤其是在人口稠密的非洲和亚洲地区。通过提供影响早期人口及其水，植物和狩猎资源的环境变化的记录，这也将对了解非洲的人类进化和散布的后期阶段也具有重要意义。

项目成果

Reanalysis of the Atmospheric Radiocarbon Calibration Record from Lake Suigetsu, Japan

• DOI: 10.1017/rdc.2020.18
• 发表时间: 2020-03
• 期刊: Radiocarbon
• 影响因子: 8.3
• 作者: C. Bronk Ramsey;T. Heaton;G. Schlolaut;R. Staff;C. Bryant;A. Brauer;H. Lamb;M. Marshall;T. Nakagawa

The Hominin Sites and Paleolakes Drilling Project

古人类遗址和古湖钻探项目

• DOI: 10.4207/pa.2017.art104
• 发表时间: 2017
• 期刊: Paleoanthropology
• 作者: Christopher Campisano

Advanced Hyperspectral Analysis of Sediment Core Samples from the Chew Bahir Basin, Ethiopian Rift, in the Spectral Range from 0.25 to 17 µm: Support for Climate Proxy Interpretation

对埃塞俄比亚裂谷 Chew Bahir 盆地沉积物核心样本进行高级高光谱分析，光谱范围为 0.25 至 17 µm：支持气候代理解释

• DOI: 10.3389/feart.2021.606588
• 发表时间: 2021
• 期刊: Frontiers in Earth Science
• 影响因子: 2.9
• 作者: Arnold G

John Birks: Pioneer in quantitative palaeoecology

约翰·伯克斯：定量古生态学的先驱

• DOI: 10.1177/0959683614556390
• 发表时间: 2014
• 期刊: The Holocene
• 作者: Battarbee R

Reconstructing the Environmental Context of Human Origins in Eastern Africa Through Scientific Drilling

通过科学钻探重建东非人类起源的环境背景

• DOI: 10.1146/annurev-earth-031920-081947
• 发表时间: 2022
• 期刊: Annual Review of Earth and Planetary Sciences
• 影响因子: 14.9
• 作者: Cohen, Andrew S.;Campisano, Christopher J.;Arrowsmith, J. Ramón;Asrat, Asfawossen;Beck, Catherine C.;Behrensmeyer, Anna K.;Deino, Alan L.;Feibel, Craig S.;Foerster, Verena;Kingston, John D.
• 通讯作者: Kingston, John D.