气候变化领域集成服务门户(CCPortal): Abrupt shifts of the Sahara-Sahel boundary during Heinrich stadials demonstrated on a sediment core transect

CCPortal

DOI	https://doi.org/10.1594/PANGAEA.820486
	Abrupt shifts of the Sahara-Sahel boundary during Heinrich stadials demonstrated on a sediment core transect
	Collins; James A; Govin; Aline; Mulitza; Stefan; Heslop; David; Zabel; Matthias; Hartmann; Jens; Röhl; Ursula; Wefer; Gerold
发布日期	2013-10-16
数据集类型	dataset
英文简介	Relict dune fields that are found as far south as 14° N in the modern-day African Sahel are testament to equatorward expansions of the Sahara desert during the Late Pleistocene. However, the discontinuous nature of dune records means that abrupt millennial-timescale climate events are not always resolved. High-resolution marine core studies have identified Heinrich stadials as the dustiest periods of the last glacial in West Africa although the spatial evolution of dust export on millennial timescales has so far not been investigated. We use the major-element composition of four high-resolution marine sediment cores to reconstruct the spatial extent of Saharan-dust versus river-sediment input to the continental margin from West Africa over the last 60 ka. This allows us to map the position of the sediment composition corresponding to the Sahara-Sahel boundary. Our records indicate that the Sahara-Sahel boundary reached its most southerly position (13° N) during Heinrich stadials and hence suggest that these were the periods when the sand dunes formed at 14° N on the continent. Heinrich stadials are associated with cold North Atlantic sea surface temperatures which appear to have triggered abrupt increases of aridity and wind strength in the Sahel. Our study illustrates the influence of the Atlantic meridional overturning circulation on the position of the Sahara-Sahel boundary and on global atmospheric dust loading.
空间范围	Median Latitude: 14.358395 * Median Longitude: -17.270835 * South-bound Latitude: 3.065000 * West-bound Longitude: -20.998300 * North-bound Latitude: 36.023500 * East-bound Longitude: -7.666830
时间范围	1991-12-03T00:00:00 - 2005-07-20T13:59:00
语种	英语
国家	国际
学科大类	气候变化
学科子类	气候变化
文献类型	数据集
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/233560
推荐引用方式 GB/T 7714	Collins,James A,Govin,et al. Abrupt shifts of the Sahara-Sahel boundary during Heinrich stadials demonstrated on a sediment core transect.2013-10-16.https://doi.org/10.1594/PANGAEA.820486.