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

Re-establishing glacier monitoring in Kyrgyzstan and Uzbekistan, Central Asia

Hoelzle, Martin ; Azisov, Erlan ; Barandun, Martina ; Huss, Matthias ; Farinotti, Daniel ; Gafurov, Abror ; Hagg, Wilfried ; Kenzhebaev, Ruslan ; Kronenberg, Marlene ; Machguth, Horst ; Merkushkin, Alexandr ; Moldobekov, Bolot ; Petrov, Maxim ; Saks, Tomas ; Salzmann, Nadine ; Schöne, Tilo ; Tarasov, Yuri ; Usubaliev, Ryskul ; Vorogushyn, Sergiy ; Yakovlev, Andrey ; Zemp, Michael

In: Geoscientific Instrumentation, Methods and Data Systems, 2017, vol. 6, no. 2, p. 397–418

Glacier mass loss is among the clearest indicators of atmospheric warming. The observation of these changes is one of the major objectives of the international climate monitoring strategy developed by the Global Climate Observing System (GCOS). Long-term glacier mass balance measurements are furthermore the basis for calibrating and validating models simulating future runoff of glacierised...

Université de Fribourg

Glacier monitoring and capacity building: important ingredients for sustainable mountain development

Nussbaumer, Samuel U. ; Hoelzle, Martin ; Hüsler, Fabia ; Huggel, Christian ; Salzmann, Nadine ; Zemp, Michael

In: Mountain Research and Development, 2017, vol. 37, no. 1, p. 141–152

Glacier observation data from major mountain regions of the world are key to improving our understanding of glacier changes: they deliver fundamental baseline information for climatological, hydrological, and hazard assessments. In many mountain ecosystems, as well as in the adjacent lowlands, glaciers play a crucial role in freshwater provision and regulation. This article first presents the...

Université de Fribourg

Historical analysis and visualization of the retreat of Findelengletscher, Switzerland, 1859–2010

Rastner, P. ; Joerg, P.C. ; Huss, Matthias ; Zemp, Michael

In: Global and Planetary Change, 2016, vol. 145, p. 67–77

Since the end of the Little Ice Age around 1850, glaciers in Europe have strongly retreated. Thanks to early topographic surveys in Switzerland, accurate maps are available, which enable us to trace glacier changes back in time. The earliest map for all of Switzerland that is usable for a detailed analysis is the Dufour map from around 1850 with subsequent topographic maps on a ~ 20 year...

Université de Fribourg

Mass balance re-analysis of Findelengletscher, Switzerland; benefits of extensive snow accumulation measurements

Sold, Leo ; Huss, Matthias ; Machguth, Horst ; Joerg, Philip C. ; Leysinger Vieli, Gwendolyn ; Linsbauer, Andreas ; Salzmann, Nadine ; Zemp, Michael ; Hoelzle, Martin

In: Front. Earth Sci. - Cryospheric Sciences, 2016, p. 18

A re-analysis is presented here of a 10 year mass balance series at Findelengletscher, a temperate mountain glacier in Switzerland. Calculating glacier-wide mass balance from the set of glaciological point balance observations using conventional approaches, such as the profile or contour method, resulted in significant deviations from the reference value given by the geodetic mass...

Université de Fribourg

Dendritic subglacial drainage systems in cold glaciers formed by cut-and-closure processes

Naegeli, Kathrin ; Lovell, Harold ; Zemp, Michael ; Benn, Douglas I.

In: Geografiska Annaler: Series A, Physical Geography, 2014, vol. 96, no. 4, p. 591–608

The routing and storage of meltwater and the configuration of drainage systems in glaciers exert a profound influence on glacier behaviour. However, little is known about the hydrological systems of cold glaciers, which form a significant proportion of the total glacier population in the climate sensitive region of the High Arctic. Using glacio-speleological techniques, we obtained direct access...

Université de Fribourg

A database of worldwide glacier thickness observations

Gärtner-Roer, I. ; 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

Towards remote monitoring of sub-seasonal glacier mass balance

Huss, Matthias ; Sold, Leo ; Hoelzle, Martin ; Stokvis, Mazzal ; Salzmann, Nadine ; Farinotti, Daniel ; Zemp, Michael

In: Annals of Glaciology, 2013, vol. 54, no. 63, p. 75–83

This study presents a method that allows continuous monitoring of mass balance for remote or inaccessible glaciers, based on repeated oblique photography. Hourly to daily pictures from two automatic cameras overlooking two large valley glaciers in the Swiss Alps are available for eight ablation seasons (2004–11) in total. We determine the fraction of snow-covered glacier surface from...

Université de Fribourg

Methodological approaches to infer end-of-winter snow distribution on alpine glaciers

Sold, Leo ; Huss, Matthias ; Hoelzle, Martin ; Andereggen, Hubert ; Joerg, Philip C. ; Zemp, Michael

In: Journal of Glaciology, 2013, vol. 59, no. 218, p. 1047–1059

Snow accumulation is an important component of the mass balance of alpine glaciers. To improve our understanding of the processes related to accumulation and their representation in state-of-the-art mass-balance models, extensive field measurements are required. We present measurements of snow accumulation distribution on Findelengletscher, Switzerland, for April 2010 using (1) in situ snow...

Université de Fribourg

High uncertainty in 21st century runoff projections from glacierized basins

Huss, Matthias ; Zemp, Michael ; Joerg, Philip C. ; Salzmann, Nadine

In: Journal of Hydrology, 2014, vol. 510, p. 35–48

Glacier response to a changing climate and its impact on runoff is understood in general terms, but model-based projections are affected by considerable uncertainties. They originate from the driving climate model, input data quality, and simplifications in the glacio-hydrological model and hamper the reliability of the simulations. Here, an integrative assessment of the uncertainty in 21st...