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Pliocene palaeoclimate off SE Africa: Insights from IODP Expedition 361

非洲东南部的上新世古气候：IODP 361 号探险队的见解

基本信息

批准号：
NE/N020286/1
负责人：
Caroline Lear
金额：
$ 7.21万
依托单位：
CARDIFF UNIVERSITY
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2016
资助国家：
英国
起止时间：
2016 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FN020286%2F1
关键词：
Pliocene palaeoclimate off SE Africa

项目摘要

It has been suggested that East Africa has undergone strong aridification between 3-5 million years ago as a consequence of changes in the source water distribution through the Indonesian seaway into the Indian Ocean [deMenocal, 1995; Cane and Molnar, 2001]. Results from an ocean circulation model showed that the northward displacement of New Guinea, about 5 Myr ago, may have switched the source of flow through Indonesia from warm South Pacifc to relatively cold North Pacifc waters. In the modern climate there is a strong link between east African rainfall and Indian Ocean SST, with warmer temperatures associated with more rain [Goddard and Graham, 1999]. Assuming that the modern ocean circulation system worked in a similar way in the Pliocene, the consequence of a tectonically driven northward move of New Guinea would have caused a reduction in sea surface temperatures in the Indian Ocean ultimately leading to reduced rainfall over eastern Africa. Why is it important to study climate changes in East/southeast Africa over that time period? We all come from Africa. We know that major steps in the evolution of African hominids and the emergence of the genus Homo in East Africa occurred in the Pliocene [Bobe and Behrensmeyer, 2004]. These developments seem to fall into times of major global and regional climatic changes especially with shifts to more arid, open environmental conditions in Africa near 2.8 Ma [deMenocal, 1995]. The change from humid to more arid conditions in East Africa has been linked mainly to remote forcing by cold North Atlantic sea-surface temperatures associated with the onset of Northern Hemisphere glacial cycles[deMenocal, 1995]. Here, however, we want to test if instead a cooling in the southwest Indian Ocean temperature due to a change of water through the archipelago of Indonesia drove changes in East and southeast Africa rainfall variability.

有人认为，东非在300万至500万年前经历了强烈的干旱化，这是通过印度尼西亚海道进入印度洋的水源分布变化的结果[deMenocal, 1995；Cane and Molnar, 2001]。海洋环流模型的结果显示，大约5万年前新几内亚向北移动，可能使流经印度尼西亚的水流源从温暖的南太平洋转向了相对寒冷的北太平洋水域。在现代气候中，东非降雨与印度洋海温之间有很强的联系，温度升高与降雨增多有关[Goddard and Graham， 1999]。假设现代海洋环流系统在上新世以类似的方式运作，构造驱动的新几内亚向北移动的结果将导致印度洋海面温度降低，最终导致非洲东部降雨减少。为什么研究非洲东部/东南部那段时间的气候变化很重要？我们都来自非洲。我们知道，非洲古人类进化的主要步骤和东非人属的出现发生在上新世[Bobe和Behrensmeyer， 2004]。这些发展似乎属于主要的全球和区域气候变化时期，特别是在2.8 Ma附近非洲转向更干旱、更开放的环境条件[deMenocal， 1995]。东非从潮湿到更干旱的变化主要与北半球冰期旋回开始引起的北大西洋海表低温的远程强迫有关[deMenocal， 1995]。然而，在这里，我们想测试的是，印度尼西亚群岛的海水变化是否导致了西南印度洋温度的下降，从而导致了非洲东部和东南部的降雨变化。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Development of a protocol to obtain the composition of terrigenous detritus in marine sediments -a pilot study from International Ocean Discovery Program Expedition 361

DOI：
10.1016/j.chemgeo.2019.119449
发表时间：
2020-03
期刊：
Chemical Geology
影响因子：
3.9
作者：
M. Simon;D. P. Babin;S. Goldstein;M. Cai;Tanzhuo Liu;Xibin Han;Anne A. Haws;M. Johns;C. Lear;S. Hemming
通讯作者：
M. Simon;D. P. Babin;S. Goldstein;M. Cai;Tanzhuo Liu;Xibin Han;Anne A. Haws;M. Johns;C. Lear;S. Hemming

Pliocene Palaeoclimate off Southeastern Africa: Insights from IODP Expedition 361

非洲东南部的上新世古气候：IODP 361 号探险队的见解