The “Combe Maudite”: its secrets revealed in time lapse
Interview with Luc Moreau - Glaciologist - Partner and friend of Enlaps
The new Tikee camera recently installed and connected allows us to follow the glacier of the Combe Maudite:
A unique installation place!
Luc Moreau, glaciologist associated with the Edytem CNRS Laboratory, and passionate about the natural movement of glaciers, has chosen an incredible spot to install one of his Tikee cameras.
Luc Moreau during the installation of the Tikee connected camera
A rocky peak, overhanging the "Combe Maudite", a wild place, a real "dead end" in which flows in a cascade of seracs the overflow of ice of the famous Mont Maudit. This combe then feeds a large part of the Bossons glacier which flows under the effect of its weight and the slope towards the Chamonix valley.
The Tikee camera contemplates a breathtaking panorama.
The 220° field of view of the Tikee camera allows us to enjoy (from left to right) the Aiguille du Midi, the three Monts (Mont Blanc du Tacul, Mont Maudit, Mont Blanc) and below on the right, the Grands Mulets refuge. Ludovic, the refuge keeper, welcomes climbers from mid-March to the end of July to discover this majestic site.
Can you find the 2 climbers on this picture, which gives an idea of the titanic scale of these places ;) - From left to right : Aiguille du Midi, Mont Blanc du Tacul, Mont Maudit, Mont Blanc
1 year of information-rich time lapse
The camera took pictures during 1 year in order to visualize the flow of the glacier during the seasons...
Observe on the time lapse video the vertical ice flows, which come, under the effect of their weight, to feed, from the cold high altitudes where they are made, the cursed combe. These are "cold glaciers" located above 4000m in the Alps, with negative temperatures at their base, which adhere to the rock (-15°C at the summit of Mon Blanc). But due to global warming, some cold glaciers close to the melting point around 3700m can become slippery and are monitored by glaciologists. If the base of the glacier warms up, they become "temperate" at their base, and can be dangerous for people like the nearby glacier of Taconnaz.
The movement of the glacier: its weight and the slope!
The Bossons glacier is temperate, and we can see on the images that it slides as a block, but it deforms on its edges where the friction on the rock slows the glacier down. The visco-plastic ice deforms but also fractures and crevasses open up as it flows. Its deformation exists especially on its banks and in depth, or in the breaks of slope.
The speed of the flow is thus the result of the mass of the glacier which makes it slide down the slope and of its deformation.
The movement of the glacier digs the valleys of the mountains!
On the edge of the glacier, you can observe glacial erosion: the mixture of rock and ice that flows out wears down the rock. This erosion has formed a ridge over the course of time and the great glaciations, on which the Grands Mulets refuge is located today. These are crystalline schists (or gneiss), while the right bank of the glacier is made of granite. The cursed combe hides the limit between these two rocks which goes up to the summit of the Mont Blanc which we see at the bottom and far above the combe...
The concept of the timelapse is particularly adapted to glaciology. It highlights the flow of glaciers under the effect of their weight, invisible movement to the naked eye but revealed by these images, variations in length, surface condition, melting snow. The cameras record for us what we miss to see between two visits!
The historical anecdote
Above the ridge of the refuge, you can see the culminating rock of the "happy return" in the shape of a pyramid. On August 8 and 9, 1786, during the first ascent of Mont Blanc, Jacques Balmat and Michel Paccard bivouacked after their legendary ascent at the foot of this famous rock, which was thus named. This ridge and this rock form a "Nunataq", an Inuit word meaning rock in the middle of the ice.
The effects of global warming
We reach the refuge by passing on the right side of the ridge (on the right of the refuge on the picture). The refuge closes from mid-July in the middle of the season because the frequentation decreases cruelly, the access path becoming too crevassed. It is rather the winter and spring itinerary for the descent of Mont Blanc by ski!
The melting of our glaciers is fast, very fast, and we didn't think so in 1980 when they were growing! However, today they lose the equivalent of one to two meters of ice on their entire surface every year, that is to say if they are not going to resist very long.
The observation of glaciers by these long term images helps to better understand the flow of the mass and its variations over time. But of course, annual in situ measurements are essential to understand these variations and the glacier risks for the safety of populations and high mountain infrastructures in this context of climate change. As the zero degree isotherm rises, cold glaciers warm up and become temperate glaciers, hanging glaciers fall off more easily, temperate glaciers shrink very quickly and their moraines or glacial deposits fall away. These changes are responsible for more and more frequent and important falls of ice and stones following the melting of ice in the fractures of the high mountain rock faces, the famous "permafrost", which is deteriorating.
These time lapses are an aid to understanding, visualizing and remembering the rapid changes taking place before our eyes, anticipating and simulating what awaits us...
But let's not forget the aesthetics of these fragile and moving environments that have captivated us since the dawn of time, and let's try to avoid their disappearance at all costs because they are the source of this vital water cycle that keeps us alive every day!
Never travel the glaciers alone or badly equipped, always be roped up long, and have a minimum of security notions (see the website of the association La Chamoniarde).
Thanks again to Luc for these aesthetic, scientific and educational images!