Decadal record of climate variability spanning the past 700 yr in the Southern Tropics of East Africa

Biogenic silica profiles in varved sediments from northern Lake Malawi (Nyasa), East Africa, span the past 700 yr and reflect past primary productivity in the overlying waters. On a centennial scale this has been influenced by lake level and a consequent shift in the location of high diatom productivity within the lake basin. Primary production was higher during the Little Ice Age, an arid period from about A.D. 1570 to 1850, when lake level was about 120 m lower than during the previous three centuries or the past 150 yr.