| dc.description.abstract | Radiocarbon-dated lacustrine sedimentary evidence indicates
that glaciers of variable size occupied the southwestern
cirques on Mount Kenya during much of the last
6000 years. Pro-glacial lacustrine sediments obtained from
Hausberg Tarn reveal distinct variations in rock-flour
content whereas the sediments in Oblong Tarn, a nearby
non-pro-glacial lake of similar size and appearance to
Hausberg Tarn show no such variations. The lamination
is therefore likely to be directly related to erosion by the
glaciers draining into the upper lake in Hausberg Valley.
Six major periods of glacier advances have been dated to
shortly before 5700, 4500-3900, 3500-3300, 3200-2300,
1300-1200, and 600-400 cal. years BP. Radiocarbon
dating of the bottom sediments from both Naro Moru and
Hausberg Tarn, is consistent with a marked glacier expansion
that occurred shortly before 5700 cal. years BP. This
advance reached approximately 1 km farther downvalley
compared with the advances of the Little Ice Age. Modelling
of the climate conditions required for this mid-
Holocene Mount Kenya advance shows that a lowering of
the equilibrium line altitude (ELA) by 100 m for a few
hundred years could cause a glacier advance of the
inferred magnitude. The glacier advances are attributed
primarily to changes in temperature because several
independent paleoclimatic studies from East Africa and
other areas affected by the Indian monsoon indicate a
relatively dry climate at times of glacier advance on Mount
Kenya. | en |
