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| Titel |
Sensitivity of very small glaciers in the Swiss Alps to future climate change |
| VerfasserIn |
Matthias Huss, Mauro Fischer |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250125946
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| Publikation (Nr.) |
 EGU/EGU2016-5605.pdf |
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| Zusammenfassung |
| Very small glaciers (<0.5km2) currently account for up to 80% of the total number of
glaciers in mountain ranges around the globe. Although their total area and volume is small
compared to larger glaciers, they are a relevant component of the cryosphere contributing to
landscape formation, local hydrology and sea-level rise. Very small glaciers have generally
shorter response times than valley glaciers and their mass balance is strongly dependent on
snow redistribution processes. Worldwide glacier monitoring has focused on medium-sized to
large glaciers leaving us with a relatively limited understanding of the behavior of very small
glaciers. With warming climate there is an increasing concern that very small glaciers might
be the first to disappear. Already in the next decades this might result in the complete
deglaciation of mountain ranges with glacier equilibrium lines close to the highest
peaks.
Here, we present a comprehensive modeling framework to assess past and future changes
of very small glaciers at the mountain-range scale. Among other processes our model
accounts for snow redistribution, changes in glacier geometry and the time-varying effect of
supraglacial debris. It computes the mass balance distribution, the englacial temperature
regime and proglacial runoff. The past evolution of 1’133 glaciers in the Swiss Alps is
individually constrained based on geodetic ice volume changes, and the model is
validated against an extensive data base of in-situ measurements on very small
glaciers. Our results indicate that 52% of all very small glaciers in Switzerland will
completely disappear within the next 25 years. However, a few avalanche-fed glaciers at
low elevation might be able to survive even substantial atmospheric warming. We
find highly variable sensitivities of very small glaciers to air temperature change,
gently-sloping, low-elevation, and debris-covered glaciers being most sensitive. |
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