Université de Fribourg

The abandoned ice sheet base at Camp Century, Greenland, in a warming climate

Colgan, William ; Machguth, Horst ; MacFerrin, Mike ; Colgan, Jeff D. ; As, Dirk van ; MacGregor, Joseph A.

In: Geophysical Research Letters, 2016, vol. 43, no. 15, p. 8091–8096

In 1959 the U.S. Army Corps of Engineers built Camp Century beneath the surface of the northwestern Greenland Ice Sheet. There they studied the feasibility of deploying ballistic missiles within the ice sheet. The base and its wastes were abandoned with minimal decommissioning in 1967, under the assumption they would be preserved for eternity by perpetually accumulating snowfall. Here we show...

Université de Fribourg

Assessment of evolution and risks of glacier lake outbursts in the Djungarskiy Alatau, Central Asia, using Landsat imagery and glacier bed topography modelling

Kapitsa, Vassiliy ; Shahgedanova, Maria ; Machguth, Horst ; Severskiy, Igor ; Medeu, Akhmetkal

In: Nat. Hazards Earth Syst. Sci., 2017, vol. 17, no. 10, p. 1837–1856

Changes in the abundance and area of mountain lakes in the Djungarskiy (Jetysu) Alatau between 2002 and 2014 were investigated using Landsat imagery. The number of lakes increased by 6.2 % from 599 to 636 with a growth rate of 0.51 % a−1. The combined areas were 16.26 ± 0.85 to 17.35 ± 0.92 km2 respectively and the overall change was within the uncertainty of measurements....

Université de Fribourg

Calculating distributed glacier mass balance for the Swiss Alps from regional climate model output: A methodical description and interpretation of the results

Machguth, Horst ; Paul, Frank ; Kotlarski, Sven ; Hoelzle, Martin

In: Journal of Geophysical Research, 2009, vol. 114, p. D19106

This study aims at giving a methodical description of the use of gridded output from a regional climate model (RCM) for the calculation of glacier mass balance distribution for the perimeter of the Swiss Alps. The mass balance model runs at daily steps and 100 m spatial resolution, while the regional model (REMO) RCM provides daily grids (∼18 km resolution) of dynamically downscaled reanalysis...

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...

Université de Fribourg

A consensus estimate for the ice thickness distribution of all glaciers on Earth

Farinotti, Daniel ; Huss, Matthias ; Fürst, Johannes J. ; Landmann, Johannes ; Machguth, Horst ; Maussion, Fabien ; Pandit, Ankur

In: Nature Geoscience, 2019, vol. 12, no. 3, p. 168–173

Knowledge of the ice thickness distribution of the world’s glaciers is a fundamental prerequisite for a range of studies. Projections of future glacier change, estimates of the available freshwater resources or assessments of potential sea-level rise all need glacier ice thickness to be accurately constrained. Previous estimates of global glacier volumes are mostly based on scaling...

Université de Fribourg

A daily, 1 km resolution data set of downscaled Greenland ice sheet surface mass balance (1958–2015)

Noël, Brice ; Berg, Willem Jan van de ; Machguth, Horst ; Lhermitte, Stef ; Howat, Ian ; Fettweis, Xavier ; Broeke, Michiel R. van den

In: The Cryosphere, 2016, vol. 10, no. 5, p. 2361–2377

This study presents a data set of daily, 1 km resolution Greenland ice sheet (GrIS) surface mass balance (SMB) covering the period 1958–2015. Applying corrections for elevation, bare ice albedo and accumulation bias, the high-resolution product is statistically downscaled from the native daily output of the polar regional climate model RACMO2.3 at 11 km. The data set includes all...

Université de Fribourg

A database of worldwide glacier thickness observations

Gärtner-Roer, Isabelle ; Naegeli, K. ; Huss, Matthias ; Knecht, T. ; Machguth, Horst ; Zemp, Michael

In: Global and Planetary Change, 2014, vol. 122, p. 330–344

One of the grand challenges in glacier research is to assess the total ice volume and its global distribution. Over the past few decades the compilation of a world glacier inventory has been well-advanced both in institutional set-up and in spatial coverage. The inventory is restricted to glacier surface observations. However, although thickness has been observed on many glaciers and ice caps...

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

Estimating the volume of glaciers in the Himalayan–Karakoram region using different methods

Frey, H. ; Machguth, Horst ; Huss, Matthias ; Huggel, C. ; Bajracharya, S. ; Bolch, T. ; Kulkarni, A. ; Linsbauer, Andreas ; Salzmann, Nadine ; Stoffel, Markus

In: The Cryosphere, 2014, vol. 8, no. 6, p. 2313–2333

Ice volume estimates are crucial for assessing water reserves stored in glaciers. Due to its large glacier coverage, such estimates are of particular interest for the Himalayan–Karakoram (HK) region. In this study, different existing methodologies are used to estimate the ice reserves: three area–volume relations, one slope-dependent volume estimation method, and two ice-thickness...

Université de Fribourg

Firn data compilation reveals widespread decrease of firn air content in western Greenland

Vandecrux, Baptiste ; MacFerrin, Michael ; Machguth, Horst ; Colgan, William T. ; As, Dirk van ; Heilig, Achim ; Stevens, C. Max ; Charalampidis, Charalampos ; Fausto, Robert S. ; Morris, Elizabeth M. ; Mosley-Thompson, Ellen ; Koenig, Lora ; Montgomery, Lynn N. ; Miège, Clément ; Simonsen, Sebastian B. ; Ingeman-Nielsen, Thomas ; Box, Jason E.

In: The Cryosphere, 2019, vol. 13, no. 3, p. 845–859

The perennial snow, or firn, on the Greenland ice sheet each summer stores part of the meltwater formed at the surface, buffering the ice sheet’s contribution to sea level. We gathered observations of firn air content, indicative of the space available in the firn to retain meltwater, and find that this air content remained stable in cold regions of the firn over the last 65 years but...