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.

有人提出，由于印度尼西亚海道进入印度洋的源水分配变化，东非在3-500万年前进行了强大的干旱化[Demenocal，1995; Cane and Molnar，2001]。海洋循环模型的结果表明，新几内亚的北部位移（大约5 Myr）可能已将流经印度尼西亚的流源从温暖的南皮里夫（South Pacifc）切换到相对较冷的北Pacifc水域。在现代气候中，东非降雨与印度洋SST之间存在着密切的联系，温度较高，与更多的降雨有关[Goddard and Graham，1999]。假设现代海洋循环系统在上新世上以类似的方式起作用，那么新几内亚构造驱动的北部移动的后果将导致印度洋的海面温度降低，最终导致东非东非的降雨量下降。为什么在此期间研究东/东南部的气候变化很重要？我们都来自非洲。我们知道，非洲人类的演变发展和东非属属的出现发生在上新世[Bobe and Behrensmeyer，2004年]。这些发展似乎属于全球和区域气候发生重大变化的时代，尤其是随着非洲更为干旱，开放的环境状况的转变，接近2.8 Ma [Demenocal，1995]。从潮湿到更干旱的条件的变化主要与北大西洋北大西洋海面的偏远强迫与北半球冰川周期发作相关的温度相关[Demenocal，1995]。但是，在这里，我们要测试由于印度尼西亚群岛的水变化而导致西南印度海洋温度的冷却是否会导致东非东部和东南部的降雨变化变化。

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