New monitoring techniques for understanding the response of very small glaciers to climate change

Alpine glacier research has traditionally focussed on medium- to large-sized valley glaciers. Very small glaciers (VSGs, here defined as being smaller than 0.5km²) have until now received little attention. Empirical knowledge is sparse and based mainly on studies focussing on very small cirque glaciers in southern Europe. However, VSGs are omnipresent in most mountain ranges and typically account for approximately 80% of the total number of glaciers worldwide. They exist either where mountain peaks are slightly higher than the climatic equilibrium line altitude (ELA), or at far lower elevations where local topographic conditions enhance snow accumulation and/or reduce ice ablation. Although the total area and volume of VSGs are relatively small compared to medium- to large-sized glaciers, they remain to be relevant components of the high-mountain cryosphere. For example, they impact the hydrological regime of poorly glacierized drainage basins, affect landscape formation, provide vital remnants of snow and ice for alpine winter tourism resorts, can trigger natural hazards, and can act as long-term climate proxies. VSGs even notably contribute to current sea level rise due to their vast number. Thus, our understanding about the dynamics and sensitivity of VSGs is important but not yet complete. This terminated project aimed to close this knowledge gap for the Swiss Alps.

Research aims:
(1) What is the current state of VSGs in the Swiss Alps and how did they react to observed atmospheric warming over the past decades?
(2) What is the sensitivity of VSGs in Switzerland to future changes in the climatic forcing and how long can they be expected to survive?
(3) What is the potential and what are the shortcomings of applying repeated terrestrial laser scanning surveys to derive annual surface elevation and geodetic mass changes of very small alpine glaciers?

Methods/methodology of the project: An integrated study approach was applied, including in-situ measurements on selected study glaciers (direct glaciological and TLS-derived geodetic mass balance, ice thickness distribution, surface velocity and temperature regime), remote sensing data to assess three-dimensional glacier changes over the past decades, and modelling to estimate the future glacier evolution at the mountain range scale.

Study area: Swiss Alps

• Publications

  • FISCHER, M., HUSS, M., KUMMERT, M., & HOELZLE, M., 2016: Application and validation of long-range terrestrial laser scanning to monitor the mass balance of very small glaciers in the Swiss Alps. The Cryosphere, 10, 1279-1295, doi:10.5194/tc-10-1279-2016.(Corresponding discussion paper: The Cryosphere Discuss., doi:10.5194/tc-2016-46)

  • CAPT, M., BOSSON, J.-B., FISCHER, M., MICHELETTI, N., & LAMBIEL, C., 2016: Decadal evolution of a very small heavily debris-covered glacier in an Alpine permafrost environment. Journal of Glaciology, doi: 10.1017/jog.2016.56.

  • HUSS, M., & FISCHER, M., 2016: Sensitivity of very small glaciers in the Swiss Alps to future climate change. Frontiers in Earth Science., 4, 34,  doi:10.3389/feart.2016.00034.

  • FISCHER, M., HUSS, M., & HOELZLE, M., 2015: Surface elevation and mass changes of all Swiss glaciers 1980–2010. The Cryosphere, 9, 525-540, doi:10.5194/tc-9-525-2015.(Corresponding discussion paper: The Cryosphere Discuss., 8, 4581-4617, doi:10.5194/tcd-8-4581-2014)

  • FISCHER, M., HUSS, M., BARBOUX, C., & HOELZLE, M., 2014: The new Swiss Glacier Inventory SGI2010: Relevance of using high-resolution source data in areas dominated by very small glaciers. Arctic, Antarctic, and Alpine Research, 46(4),  933-945, doi: 10.1657/1938-4246-46.4.933.