Oberaletschgletscher
Past extents come from the Swiss Glacier Inventories of 1850, 1931, 1973 and 2016. Future extents are illustrative: each glacier’s projected area (OGGM, median of CMIP6 climate models) is removed from its lowest ice upward. About the scenarios.
Oberaletschgletscher is the 5th-largest glacier in Switzerland, covering 17.05 km² in the canton of Valais. Its ice spans 2,140 to 3,826 m and faces south-east. Its meltwater drains to the Rhône and on to the Mediterranean. In 1850 it was part of a larger ice body of 26.6 km², which has since split into 7 glaciers covering 18.5 km² in 2016 (−31%). Its tongue has been measured 41 times since 1870. In total it has retreated 1,520 m, about 9.9 m a year. Between 1969 and 2023 its surface dropped by 47 m on average. With strong climate protection (SSP1-2.6), about 22% of its 2020 ice would remain in 2100. With very high emissions (SSP5-8.5) it would be gone around 2080. Its meltwater peaked around 2023.
In pictures
What remains in 2100
Meltwater
Million m³ of water per year, 11-year mean
The record
Length change since 1870
Position of the glacier tongue, measured in the field almost every year. Hover for each measurement.
Thinning since 1969
Average change in surface height, from comparing elevation models made from maps, aerial images and laser scans.
Facts
Area over time
Past areas are the ice body this glacier belonged to at the time. Projections: OGGM median, SSP2-4.5.
- SGI id
- B36-01
- Canton
- Valais
- River
- Rhône → Mediterranean
- Basin
- Lötschental–Aletsch
- Location
- 46.4230° N, 7.9640° E · swisstopo map
- Elevation
- 2,140–3,826 m, median 2,902 m
- Slope, aspect
- 22°, south-east
- Debris cover
- 6.14 km² (36% of the area)
- Inventory image
- 2017
- Ice volume (model)
- ≈ 1.03 km³ in 2020 (OGGM)
- RGI ids
- RGI60-11.01827, RGI60-11.01836, RGI60-11.01867, RGI60-11.01969
- In 1850 joined with
- Beichspitze E, Beichgrat SE 1, Beichgrat SE 2, Oberaletschfirn, Gross Fusshorn NW, Unnamed glacier B36-59
More in the Lötschental–Aletsch basin
- Grosser Aletschgletscher78.49 km²
- Langgletscher8.01 km²
- Mittelaletschgletscher6.61 km²
- Tellingletscher5.13 km²
- Üssre Baltschiedergletscher3.56 km²
- Driestgletscher1.80 km²
- Innre Baltschiedergletscher1.68 km²
- Jegigletscher NE1.33 km²
- Joligletscher0.86 km²
- Zenbächengletscher0.82 km²
- Dischliggletscher0.64 km²
- Unnamed glacier B36-590.64 km²
Sources
- Linsbauer et al. (2021). The new Swiss Glacier Inventory SGI2016. Frontiers in Earth Science 9. doi.org/10.3389/feart.2021.704189
- Mannerfelt et al. (2022). Halving of Swiss glacier volume since 1931 observed from terrestrial image photogrammetry. The Cryosphere 16. doi.org/10.5194/tc-16-3249-2022
- GLAMOS – Glacier Monitoring Switzerland. www.glamos.ch
- Zekollari et al. (2024). Twenty-first century global glacier evolution under CMIP6 scenarios and the role of glacier-specific observations. The Cryosphere 18 (OGGM v1.6 projections). tc.copernicus.org/articles/18/5045/2024/
Relief: swisstopo swissALTIRegio. 1850 and 1973 outlines: Maisch et al. (2000), Müller et al. (1976), Paul (2004). Length, mass balance and volume change: GLAMOS releases 2025. All sources and methods.