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.