Mass Balance Factsheet for Claridenfirn, Alps
Claridenfirn is a plateau glacier in the central Swiss Alps. It consists of several accumulation basins beneath a rugged rocky ridge, independent steep glacier fronts and several water outlets. The glacier currently (2022) extends from 2567 to 3177 m a.s.l., and covers an area of 4.1 km2. It has a mean thickness of ca. 65 m, and ice thickness is still estimated to reach over 200 m on the upper firn plateau. The principal terminus of Claridenfirn was subject to frequent ice avalanches over a vertical rock cliff until about a decade ago with frontal ablation contributing to overall mass loss by 9% on average (Huss et al., 2021). Frontal ablation has been reduced to almost zero in recent years due to glacier retreat. The local climate at Claridenfirn is characterized by high precipitation totals resulting in winter snow depths of partly over 5 meters.
Continuous measurements of winter snow accumulation and annual mass balance have been undertaken by various researchers since 1914 using a consistent methodology at two specific locations on the glacier. These seasonal point series are thus the longest direct glacier mass balance records worldwide and are characterized by an excellent documentation (Müller and Kappenberger, 1991). By combining the 100-year point measurements with decadal ice volume changes from repeated digital elevation models, glacier-wide seasonal mass balance was determined for the full time series relying on model-based extrapolation to the entire glacier surface and estimates of annual frontal ablation (Huss et al., 2021).
Mass balance measurements are performed in the frame of the programme GLAMOS (Glacier Monitoring Switzerland, www.glamos.ch). For additional information on the status of the glacier and on data relating to annual mass balance and other measurements, visit the WGMS Fluctuations of Glaciers Browser.
FACTS:
- Political unit: CH
- WGMS ID: 2660
- Latitude: 46.50°N
- Longitude: 8.53°E
- Height min: 2567 m a.s.l.
- Height max: 3177 m a.s.l.
- Measurement types: MASS BALANCE, THICKNESS CHANGE & FRONT VARIATION
- Current Principal Investigator: Matthias Huss & Colleagues
- Current Sponsoring Agency: LABORATORY OF HYDRAULICS, HYDROLOGY AND GLACIOLOGY, VAW – ETH ZURICH (ZURICH, CH)
Overview of Claridenfirn on 20 Sept 2025 (photo by M. Huss)
Claridenfirn Annual Mass Balance (WGMS)
Continuous Mass Balance (MB) measurements since 1914/15:
Additional data available: Front Variation (FV), Thickness Change (TC) and Glacier Outlines:
Selected references:
Huss, M., Bauder, A., Linsbauer, A., Gabbi, J., Kappenberger, G., Steinegger, U. and D. Farinotti 2021: More than a century of direct glacier mass-balance observations on Claridenfirn, Switzerland. Journal of Glaciology 67(264), 697–713.https://doi.org/10.1017/jog.2021.22
Müller, H. and G. Kappenberger 1991: Claridenfirn-Messungen 1914-1984. No. 40, Zürcher Geographische Schriften, Geographisches Institut der ETH Zürich, pp. 79.
GLAMOS 1881-2023, The Swiss Glaciers 1880-2022/23, Glaciological Reports No 1-142, Yearbooks of the Cryospheric Commission of the Swiss Academy of Sciences (SCNAT), published since 1964 by VAW / ETH Zurich, doi:10.18752/glrep_series