Glacière de Monlési
Glacière de Monlési is an ice cave near Couvet in Val de Travers, Switzerland. In winter cold air enters the cave from a high-lying entrance and remains trapped there during summer. It contains a considerable amount of ice througout the year despite outside avarage annual air temperatures of around 5 degress Centigrade.
Along the path to the cave. The entrance is at about 1100 m.a.s.l.
The largest access pit is somewhat hidden between trees and bushes.
Th ecave can be reached via a steep path and a ladder.
At the bottom of the pit a lot of snow remains in July.
On this hot summer day temperatures at the bottom of the pit are near freezing.
Near the entrance there is little room between the main ice body and the cave's ceiling.
Water entering the cave from above freezes and forms ice stalactites and stalagmites.
Between two cave openings. Note rock debris from the ceiling frozen into the ice.
Flow of the big ice body has caused fracturing of the stalagmite (lower right).
Ice acculumation is by freezing water entering the cave. Cold air which enters the cave in winter remains trapped here in summer.
There is some heat flow from surrounding rock to the ice; the main ice body slowly melts from below and subsides forming a cavity above.
Near the cave openings some daylight illuminates the ice formations. Note colourful biogenic and mineral deposits on the cave's ceiling.
Melting of ice consumes latent heat, which cools the air above the ice. This maintains air temperatures near zero degrees centigrade withing the cave all through summer.
When one climbs out of the pit the air gets warmer very quickly! The effect is quite spectacular indeed.
Cross section of the cave system in summer. Contrary to what the drawing shows, the ice is up to 30m thick (explanatory display near the cave).
Cross section in winter. The ice mass is not a glacier in the strict sense as it is not formed by snow accumulation and has a surface are of less then 10'000 square metres.
|Photos: Jürg Alean, during an excursion of the Schweizerischen Gesellschaft für Schnee, Eis und Permafrost, SEP June 16th, 2012; Canon EOS 5DII, 17-40mm lens, usually at f9 oder f11; within the cave 6400 ASA and no flash was used; exposure times up to 10 seconds from a tripod.|