Effect of a cold margin on ice flow at the terminus of Storglaciären, Sweden: implications for sediment transport
2011 (English)In: Journal of Glaciology, ISSN 0022-1430, Vol. 57, no 201, 77-87 p.Article in journal (Refereed) Published
The cold-based termini of polythermal glaciers are usually assumed to adhere strongly toan immobile substrate and thereby supply significant resistance to the flow of warm-based ice upglacier.This compressive environment is commonly thought to uplift basal sediment to the surface ofthe glacier by folding and thrust faulting. We present model and field evidence from the terminus ofStorglaci¨aren, Sweden, showing that the cold margin provides limited resistance to flow from up-glacier.Ice temperatures indicate that basal freezing occurs in this zone at 10−1 –10−2 ma−1, but model resultsindicate that basal motion at rates greater than 1ma−1 must, nevertheless, persist there for surface andbasal velocities to be consistent with measurements. Estimated longitudinal compressive stresses of 20–25 kPa within the terminus further indicate that basal resistance offered by the cold-based terminusis small. These results indicate that where polythermal glaciers are underlain by unlithified sediments,ice-flow trajectories and sediment transport pathways may be affected by subglacial topography andhydrology more than by the basal thermal regime
Place, publisher, year, edition, pages
2011. Vol. 57, no 201, 77-87 p.
Research subject Physical Geography
IdentifiersURN: urn:nbn:se:su:diva-57176ISI: 000288526400008OAI: oai:DiVA.org:su-57176DiVA: diva2:414505