Affiner les résultats

Type de document

Collection spécifique

Langue

Université de Fribourg

A snow density dataset for improving surface boundary conditions in greenland ice sheet firn modeling

Fausto, Robert S. ; Box, Jason E. ; Vandecrux, Baptiste ; As, Dirk van ; Steffen, Konrad ; MacFerrin, Michael J. ; Machguth, Horst ; Colgan, William ; Koenig, Lora S. ; McGrath, Daniel ; Charalampidis, Charalampos ; Braithwaite, Roger J.

In: Frontiers in Earth Science, 2018, vol. 6, p. -

The surface snow density of glaciers and ice sheets is of fundamental importance in converting volume to mass in both altimetry and surface mass balance studies, yet it is often poorly constrained. Site-specific surface snow densities are typically derived from empirical relations based on temperature and wind speed. These parameterizations commonly calculate the average density of the top...

Université de Fribourg

Numerical reconstructions of the flow and basal conditions of the Rhine glacier, European Central Alps, at the Last Glacial Maximum

Cohen, Denis ; Gillet-Chaulet, Fabien ; Haeberli, Wilfried ; Machguth, Horst ; Fischer, Urs H.

In: The Cryosphere, 2018, vol. 12, no. 8, p. 2515–2544

At the Last Glacial Maximum (LGM), the Rhine glacier in the Swiss Alps covered an area of about 16000km2. As part of an integrative study about the safety of repositories for radioactive waste under ice age conditions in Switzerland, we modeled the Rhine glacier using a thermodynamically coupled three-dimensional, transient Stokes flow and heat transport model down to a horizontal resolution...

Université de Fribourg

Elevation changes of the Holm Land Ice Cap, northeast Greenland, from 1978 to 2012–2015, derived from high-resolution digital elevation models

Albedyll, Luisa von ; Machguth, Horst ; Nussbaumer, Samuel U. ; Zemp, Michael

In: Arctic, Antarctic, and Alpine Research, 2018, vol. 50, no. 1, p. e1523638

Greenland’s peripheral glaciers and ice caps are key indicators of climate change in the Arctic, but quantitative observational data of their recent evolution are sparse. Three recently released high-resolution digital elevation models (DEMs)—AeroDEM (based on images from 1978 to 1987), ArcticDEM (2012–2015), and TanDEM-X (2010–2014)—provide the possibility to calculate elevation...

Université de Fribourg

Multi-decadal mass balance series of three Kyrgyz glaciers inferred from modelling constrained with repeated snow line observations

Barandun, Martina ; Huss, Matthias ; Usubaliev, Ryskul ; Azisov, Erlan ; Berthier, Etienne ; Kääb, Andreas ; Bolch, Tobias ; Hoelzle, Martin

In: The Cryosphere, 2018, vol. 12, no. 6, p. 1899–1919

Glacier surface mass balance observations in the Tien Shan and Pamir are relatively sparse and often discontinuous. Nevertheless, glaciers are one of the most important components of the high-mountain cryosphere in the region as they strongly influence water availability in the arid, continental and intensely populated downstream areas. This study provides reliable and continuous surface mass...

Université de Fribourg

Proglacial erosion rates and processes in a glacierized catchment in the Swiss Alps

Delaney, Ian ; Bauder, Andreas ; Huss, Matthias ; Weidmann, Yvo

In: Earth Surface Processes and Landforms, 2018, vol. 43, no. 4, p. 765–778

In the Swiss Alps, climatic changes have not only caused glacier retreat, but also likely increased sedimentation downstream of glaciers. This material either originates from below the glacier or from periglacial environments, which are exposed as glaciers retreat, and often consist of easily erodible sediment. Griesgletscher's catchment in the Swiss Alps was examined to quantify erosion in...

Université de Fribourg

The bedrock topography of Gries- and Findelengletscher

Feiger, Nadine ; Huss, Matthias ; Leinss, Silvan ; Sold, Leo ; Farinotti, Daniel

In: Geographica Helvetica, 2018, vol. 73, no. 1, p. 1–9

Knowledge of the ice thickness distribution of glaciers is important for glaciological and hydrological applications. In this contribution, we present two updated bedrock topographies and ice thickness distributions for Gries- and Findelengletscher, Switzerland. The results are based on ground-penetrating radar (GPR) measurements collected in spring 2015 and already-existing data. The GPR...

Université de Fribourg

Investigating cold based summit glaciers through direct access to the glacier base: a case study constraining the maximum age of Chli Titlis glacier, Switzerland

Bohleber, Pascal ; Hoffmann, Helene ; Kerch, Johanna ; Sold, Leo ; Fischer, Andrea

In: The Cryosphere, 2018, vol. 12, no. 1, p. 401–412

Cold glaciers at the highest locations of the European Alps have been investigated by drilling ice cores to retrieve their stratigraphic climate records. Findings like the Oetztal ice man have demonstrated that small ice bodies at summit locations of comparatively lower altitudes may also contain old ice if locally frozen to the underlying bedrock. In this case, constraining the maximum age...

Université de Fribourg

Changes in Greenland’s peripheral glaciers linked to the North Atlantic Oscillation

Bjørk?, A. A. ; Aagaard, S. ; Lütt, A. ; Khan, S. A. ; Box, J. E. ; Kjeldsen?, K. K. ; Larsen, N. K. ; Korsgaard?, N. J. ; Cappelen, J. ; Colgan, W. T. ; Machguth, Horst ; Andresen, C. S. ; Peings, Y. ; Kjær, K. H.

In: Nature Climate Change, 2018, vol. 8, no. 1, p. 48–52

Glaciers and ice caps peripheral to the main Greenland Ice Sheet contribute markedly to sea-level rise1,2,3. Their changes and variability, however, have been difficult to quantify on multi-decadal timescales due to an absence of long-term data4. Here, using historical aerial surveys, expedition photographs, spy satellite imagery and new remote-sensing products, we map glacier length...