M. Riettishati et al., A 3000-YEAR CLIMATIC RECORD FROM BIOGENIC SILICA OXYGEN ISOTOPES IN AN EQUATORIAL HIGH-ALTITUDE LAKE, Science, 281(5379), 1998, pp. 980-982
A record of oxygen isotopes in biogenic opal, 4200 to 1200 calibrated
years before the present, from a high-altitude proglacial Lake on Moun
t Kenya, East Africa, exhibits short-term fluctuations on a time scale
of centuries as well as Long-term variations. The short-term fluctuat
ions are attributed to changes in the glacier meltwater input, and the
Long-term variations are related to changes in Lake temperature. The
record indicates that the climate was warm in Equatorial East Africa f
rom 2300 to 1500 years before the present.