Publication Date:
2002-04-06
Description:
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 lake 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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Johnson, Thomas C -- Brown, Erik T -- McManus, James -- Barry, Sylvia -- Barker, Philip -- Gasse, Francois -- New York, N.Y. -- Science. 2002 Apr 5;296(5565):113-32.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Large Lakes Observatory, University of Minnesota Duluth, Duluth, MN 55812, USA. tcj@d.umn.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11935023" target="_blank"〉PubMed〈/a〉
Keywords:
Africa, Eastern
;
Atmosphere
;
*Diatoms/growth & development
;
Ecosystem
;
Fresh Water
;
Geologic Sediments/*chemistry
;
Phytoplankton/growth & development
;
Rain
;
Silicon Dioxide/*analysis
;
Time
;
*Tropical Climate
;
Volcanic Eruptions
;
Wind
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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