Publisert 16.09.2019 , sist oppdatert 09.03.2021

Glacier crevasses and surge

Crevasses are deep cracks in glacier ice that are caused by the stress of the ice moving over rocky terrain underneath. Mountaineering accidents involving falling into a crevasse during walking, skiing, hiking or climbing are numerous and can be fatal. When travelling on a glacier it is important to be able to judge glacier routes to plan where there are fewest crevasses combined with knowledge of local conditions.

Glacier surging is a phenomenon where glaciers suddenly increase in speed by at least one order of magnitude compared to their normal background speed, and in doing so transfers accumulated mass from the upper regions of the glacier downstream. The active surge phase can last from months to several years, whereas the quiescent phase is at the scale of decades or even a century. There are no surge-type glaciers on mainland Norway, but on Svalbard they make up a large percentage of all glaciers. Surging creates dangerous conditions on and around the glacier due to sudden opening of crevasses, rapid front changes and increased calving of ice where glaciers end up in water.

In the Copernicus Glacier Service project we tested if Sentinel imagery could be used for detecting surges and creating crevasse maps. We have developed a registry and map of active surges on Svalbard and attempted automated crevasse mapping in several glacier regions. The results are described in the final project report:

Andreassen, L.M. (ed.), G. Moholdt, A. Kääb, A. Messerli, T. Nagy and S.H. Winsvold. 2021.
Monitoring glaciers in mainland Norway and Svalbard using Sentinel.
NVE Rapport 3-2021, 94 p.

Sentinel-2 imagery showing a surge of Sonklarbreen, Svalbard, from 2019 to 2020.