Glacier du Giétro
Giétro Glacier
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.
In 1818 ice falling from the Giétro Glacier dammed the Drance. The dam’s failure caused the deadliest glacier flood in Swiss history. Today the glacier sits above the Mauvoisin reservoir.
Glacier du Giétro is the 43rd-largest glacier in Switzerland, covering 5.11 km² in the canton of Valais. Its ice spans 2,738 to 3,816 m and faces north-west. Its meltwater drains to the Rhône and on to the Mediterranean. In 1850, at the end of the Little Ice Age, it covered 6.44 km²; by 2016 it had lost 21% of that area. Its tongue has been measured 68 times since 1889. In total it has retreated 599 m, about 4.5 m a year. Its mass balance has been measured since 1967: on average −0.54 m of water equivalent per year, with the most negative year in 2022 (−2.96 m). Between 1934 and 2023 its surface dropped by 29 m on average. With strong climate protection (SSP1-2.6), about 2% of its 2020 ice would remain in 2100. With very high emissions (SSP5-8.5) it would be gone around 2064. Its meltwater is projected to peak around 2039.
What remains in 2100
Meltwater
Million m³ of water per year, 11-year mean
The record
Length change since 1889
Position of the glacier tongue, measured in the field almost every year. Hover for each measurement.
Mass balance 1967–2025
Ice gained (blue) or lost (red) over the whole glacier each year, in metres of water equivalent. Measured with stakes drilled into the ice.
Thinning since 1934
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
- B82-14
- Canton
- Valais
- River
- Rhône → Mediterranean
- Basin
- Dranse
- Location
- 45.9860° N, 7.3940° E · swisstopo map
- Elevation
- 2,738–3,816 m, median 3,229 m
- Slope, aspect
- 12°, north-west
- Debris cover
- 0.02 km² (0% of the area)
- Inventory image
- 2016
- Ice volume (model)
- ≈ 0.390 km³ in 2020 (OGGM)
- RGI ids
- RGI60-11.02774
More in the Dranse basin
- Glacier de Corbassière14.95 km²
- Glacier d'Otemma zentral12.59 km²
- Glacier du Brenay7.07 km²
- Glacier de Saleinaz6.69 km²
- Glacier du Mont Durand6.21 km²
- Glacier de la Tsessette zentral2.06 km²
- Glacier de Valsorey2.03 km²
- Glacier de l'A Neuve S1.94 km²
- Glacier de Boveire1.66 km²
- Glacier du Tseudet1.54 km²
- Glacier d'Orny1.31 km²
- Glacier de l'A Neuve N1.27 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/
- Ancey et al. (2019). Hydraulic reconstruction of the 1818 Giétro glacial lake outburst flood. Water Resources Research. agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019WR025274
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.