Ground Thermal Profiles from Mount Kenya, East Africa
Grab, Stefan W
Gatebe, Charles K
Kinyua, Antony M
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This paper presents and compares ground thermal regimes at 4200 and 4800 m a.s.l. on Mount Kenya's southern aspect. Temperatures were recorded using Tinytalk™ data loggers, installed at the ground surface and at depths of 1 cm, 5 cm, 10 cm and 50 cm. Temperatures were logged at 2-hour intervals over a period of 12 months (August 1998 to July 1999). The study is designed to demonstrate near-surface freeze conditions, which would have implications for contemporary periglacial landform production. Although ground freeze at 4200 m a.s.l. occurs during most nights (c. 70% at 1 cm depth), freeze penetration is restricted to the top 2 to 3 cm, such that no freeze was recorded at 5 cm depth. At 4800 m a.s.l., the diurnal frost frequency at the surface is 365 days (100%), whilst that at 10 cm depth is 165 days (45%). The paper demonstrates that a greater longevity of contemporary thin snow cover at 4800 m a.s.l. permits progressive sub-surface cooling with depth. However, the near-surface ground temperature profiles suggest that conditions are not conducive to permafrost development at the sites.