Search results for "Glacier ice accumulation"
showing 4 items of 4 documents
The Bossons glacier protects Europe's summit from erosion
2013
13 pages; International audience; The contrasting efficiency of erosion beneath cold glacier ice, beneath temperate glacier ice, and on ice-free mountain slopes is one of the key parameters in the development of relief during glacial periods. Detrital geochronology has been applied to the subglacial streams of the north face of the Mont-Blanc massif in order to estimate the efficiency of erosional processes there. Lithologically this area is composed of granite intruded at ~303 Ma within an older polymetamorphic complex. We use macroscopic features (on ~10,000 clasts) and U-Pb dating of zircon (~500 grains) to establish the provenance of the sediment transported by the glacier and its subgl…
Monitoring glacier elevation and volume changes with digital photogrammetry and GIS at Gepatschferner glacier, Austria
2006
Digital elevation models of Gepatschferner in Northern Tyrol, Austria were obtained with digital photogrammetry from high altitude stereo photo pairs and by digitizing an analogue topographic glacier map, for 1990 and 1971, respectively. A difference map was calculated to identify regions of glacier elevation increases and decreases corresponding to glacier mass gain and loss. While the glacier tongue below 2600 m showed mainly increases in glacier surface elevation as compared to 1971, the remaining glacier thickness experienced both increases and decreases. The accumulation zone above 3200 m contained several extreme cases of morphological features with altitude changes>+30 m. While the i…
Two-dimensional numerical modeling of fracturing and shear band development in glacier fronts
2014
In this contribution we present a two-dimensional numerical model of a deforming glacier front. The model is based on a hybrid lattice spring network approach where particles in the model can deform in a volume conservative visco-elastic manner but at the same time they can be compressed elastically and fracture by discrete failure. We restrict ourselves to a simple setting where the glacier sits on a frictionless slope that dips with 5–10°, the ice block is fixed on one side and has a free surface on the other. The glacier varies in viscosity and can flow at the base, whereas it is brittle at the top. Results show that the head of the glacier is unstable. Failure happens as a combination o…
Change in geometry of a high Arctic glacier to 1948 to 2013 (Austre Lovénbreen, Svalbard)
2017
International audience; The change of Austre Lovénbreen, a 4.5 km2 land-based glacier along the west coast of Spitsbergen, is investigated using geodetic methods and mass balance measurements over 1948–2013. For 2008−2013, annual mass balances computed on 36-stake measurements were obtained, in addition to annual mass balances reconstructed from the neighbouring glaciers, Midtre Lovénbreen (1968−2007) and Austre Brøggerbreen (1963−1967). The mean rate of glacier retreat for 1948–2013 is −16.7 ± 0.3 m a−1. Fluctuations in area (1948–2013 mean, −0.027 ± 0.002 km2 a−1) showed a slowing as the glacier recedes within its valley from 1990 to 1995. For 1962–2013, the average volume loss calculated…