Vertical distribution of water within the polythermal glacier Storglaciären, Sweden
2010 (English)In: Journal of Geophysical Research, ISSN 0148-0227, Vol. 115, F04002- p.Article in journal (Refereed) Published
Knowledge of water content and its distribution in polythermal glaciers is required tomodel their flow and thermal state. However, observations of water content variations withdepth in polythermal glaciers are scarce. Water content can be estimated from radiowave speed because they depend on one another. We obtained continuous profiles of radiowave speed variations with depth from zero‐offset radar profiles collected in boreholesapproximately 80 m deep in the upper ablation area of Storglaciären, northern Sweden.These profiles show that the microcrystalline water system in the temperate ice is relativelyhomogeneous. The overall hydrothermal structure at this location is composed of a 20 mthick upper layer of cold, water‐free ice, underlain by a temperate ice layer whose averagewater content is 0.6% ± 0.3%. These results are corroborated by surface radar andthermistor measurements, which show that the depth of the cold temperate transition is21 m and the calculated water content at that transition is 0.6% ± 0.1%. These findingsimply that the whole temperate ice layer is from 3 to 4 times softer than the cold ice and,consequently, that realistic ice flow models of polythermal glaciers should include theeffect of water content on viscosity.
Place, publisher, year, edition, pages
2010. Vol. 115, F04002- p.
Research subject Physical Geography
IdentifiersURN: urn:nbn:se:su:diva-43327DOI: 10.1029/2009JF001539ISI: 000282767100001OAI: oai:DiVA.org:su-43327DiVA: diva2:355969