Transient snow!

Late September into October is typically a period of transition on Kibo between the dry season and Vuli, the short rains. At this transitional time, considerable snowcover sometimes remains in the summit caldera - but in other years the mountain is bare. Hans Meyer wrote of this in 1891: "In October, when all the snowfields had disappeared, there was likewise comparatively little snow to be met with on the ice-cap".

In the past couple weeks, our friend Simon Mtuy and ultrarunner Kelly Halpin were up and down the mountain a few times and visited summit glaciers. Only very small patches of residual snow were found at the top (perfect for running). Back at the base afterwards, Simon documented a rapid transition-season change in snow cover over the course of one day, 22 October. Prior to snowfall overnight on 21-22 October, the dark volcanic rock had been absorbing a high proportion of the intense solar radiation high on the mountain, for weeks. Meyer also wrote of this: "...the dark rock is sometimes heated to such a degree that the [emitted longwave] radiation may be directly felt, and even seen in the vibration of the atmosphere over it's surface".

Simon's pair of photos nicely shows the impact of heat stored by Kibo's rocks and sand, in an otherwise extreme climate. Within the 11 hours between the photos, much of the snow evaporated and melted - while the air temperature almost certainly remained below freezing.

Thanks Simon for your observation, and for sharing the documentation!

2026 update on Furtwängler and other glaciers

Mid-October is the tail end of the dry season on Kibo, and this year conditions are reminiscent of the months prior to eastern Africa's very wet 1997-98 El Niño. My friend Simon Mtuy spent considerable time on the mountain recently, and sent some helpful photos.

The upper photo illustrates how little of the Furtwängler Glacier remains. Simon is standing next to the largest fragment; between the ice and the Uhuru Peak slope only a couple small patches of snow are visible. For scale, we estimate that a strip of ice only about 25m long remains, only one to two meters thick! Compare the current thickness with that in February 2020, when our Tanzanian helpers learned ice-climbing techniques. Additional comparisons are posted on this blog, including this synopsis from 2012; note the person in this panorama!

[UPDATE 10/21:  photo label below corrected; 2026 not 2023] 

Simon also sent photos from Kenya of the lesser-seen north side of Kibo. The entire mountain is now free of snow, and the glaciers continue their monotonous decrease in both thickness and area.

 

Although our measurements and fieldwork on the mountain have ended, fascination with the glaciers of Kibo continues. Lots of additional information is contained within this blog, and scientific results of the work can be found here.