A high-resolution paleoclimate record spanning the past 25,000 years in southern East Africa

被引:180
作者
Johnson, TC [1 ]
Brown, ET
McManus, J
Barry, S
Barker, P
Gasse, F
机构
[1] Univ Minnesota, Large Lakes Observ, Duluth, MN 55812 USA
[2] Univ Lancaster, Dept Geog, Lancaster LA1 4YB, England
[3] Univ Aix Marseille 3, CNRS, Ctr European Rech & Enseignement Geosci Environm, F-13545 Aix En Provence, France
关键词
D O I
10.1126/science.1070057
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
High-resolution profiles of the mass accumulation rate of biogenic silica and other geochemical proxies in two piston cores from northern Lake Malawi provide a climate signal for this part of tropical Africa spanning the past 25,000 years. The biogenic silica mass accumulation rate was low during the relatively dry late Pleistocene, when the river flux of silica to the take was suppressed. Millennial-scale fluctuations, due to upwelling intensity, in the late Pleistocene climate of the Lake Malawi basin appear to have been closely linked to the Northern Hemisphere climate until 11 thousand years ago. Relatively cold conditions in the Northern Hemisphere coincided with more frequent north winds over the Malawi basin, perhaps resulting from a more southward migration of the Intertropical Convergence Zone.
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页码:113 / +
页数:4
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