Documentaires. Un Glacier Alpin.

Title: Documentaires. Un Glacier Alpin.
Translated Title: 
Documentaries. An Alpine Glacier.
Duration: 
06:42
Abstract: 
Instructive Series, an Alpine Glacier, the Mer de Glace. The snow that falls on tall mountains is transformed from granular snow (neve) into bullous ice and then into compacted ice. Compacted ice glides slowly into depressions like a frozen river: this is a glacier. The Mer de Glace descends from the massif of Mont-Blanc seen here from Flegere (altitude 1,877 meters.) It’s a composite glacier, note in the distance the two tributary glaciers. Map of the Mer de Glace, the three white spots represent (from right to left) the glaciers of Geant Laschaux and Talefre. The depressions in which the snow accumulates are called Basins of Reception; a small part of one basin of reception. A hiker and two guides mount the the snowy slopes of the basin of reception of the glacier of Geant. Glacier of Geant, localization of the basin of reception. The glacier of Geant (altitude 3,400 meters). The needle of Geant dominates the glacier and disappears in a cloud (altitude 4,014 meters). Glacier of Leschaux localization (east of the glacier of Geant). The Grandes Jorasses, the Aiguille de Leschaux, altitude 3,778 meters (to the left), dominates this glacier. Glacier of Talefre merges with the Glacier of Leschaux (map). Glacier of Talefre: note the basin of reception, the mass of ice, the pulled along rocks. The surface of a glacier is not uniform. Since the bed of the glacier is narrow, the ice cracks into long and deep longitudinal crevasses. A large longitudinal crevasse of the glacier of Geant. A large crevasse, 30 meters deep. Another crevasse, note the deep grooves left by the flow of water and the melting of ice. The interior of a crevasse, the layers of ice are visible. In the expanded passages transverse crevasses form (the speed of a glacier is faster along the center than on the sides). Pyramids of ice produced by the entaglement of crevasses (Sea of Ice close to Montanvers). When the slope of the bed of the glacier suddenly increases, the ice breaks into layered blocks called "seracs". Seracs of the Glacier of Geant (altitude 2,517 meters). Seracs of the Glacier of Talefre. View of the Sea of Ice towards the confluence fo the glaciers (note their sinuous course). Needles of Grepon (3,485 meters) of Grands-Charmoz (3,432 meters) At their feet is a suspended glacier, and lower down, the Sea of Ice. To the east of the Sea of Ice is the Needle of Dru (3,759 meters). Rocky fragments detach from the summits and roll to the banks of the glacier, forming lateral moraines. A lateral moraine to the right of the Sea of Ice. A lateral moraine to the right of the Glacier of Leschaux (blocks of all sizes). When two glaciers merge their lateral moraines form together a medial moraine. Enormous blocks can be carried along by the ice (glacier of Geant). The surface of the glacier is streaked with bands of mud (note their curvature towards the center of the glacier). In the summer, the ice melts except at the shadow of rocks, which seem to be placed on feet of ice; ice tables of Talefre. Water from the melted ice flows along the surface of the glacier ... and falls into the crevasses. Lowermost point of the Sea of Ice, the ice melts and forms numerous streams of water . . . which flow between these two masses of polished rock. The torrent of Arveyron born of the Sea of Ice descends in cascades the valley of the Arve. The Sea of Ice and the Arveyron seen from the slopes of La Flegere. End.
Series Title: 
Documentaires
Translated Series Title: 
Documentaries
Series Subtitle: 
Documentaries