Spectral roughness and glacial erosion of a land-terminating section of the Greenland Ice Sheet
2015 (English)In: Geomorphology, ISSN 0169-555X, E-ISSN 1872-695X, Vol. 238, 149-159 p.Article in journal (Refereed) Published
Spectral roughness offers a significant potential for understanding the evolution of glaciated landscapes. Here, we present the first roughness study combining a high-resolution (250 to 500 m) DEM of a large land-terminating section (12,000 km2) of the Greenland Ice Sheet with the topography of the proglacial area. Subglacial roughness shows a directional dependence with consistently lower values in the ice flow direction compared to the across–flow direction. We find a correlation between low basal roughness, fast ice flow, and subglacial troughs. The northern part of the subglacial study area has an undulating topography with variable roughness, resembling the landscape in the proglacial area. In this area, there is a glacially eroded, overdeepened trough with bed elevations 510 m below sea level, consistent with warm ice and a well-lubricated bed. The southern part of the subglacial study area has higher bed elevations and higher roughness than the northern part, possibly because the bedrock consists of hard granitic gneiss as in the adjacent proglacial area. The subglacial troughs, which have been eroded to various extents, are aligned with geological weakness zones suggesting a preglacial origin. In general, there is a major geological control on the distribution of bed variability.
Place, publisher, year, edition, pages
2015. Vol. 238, 149-159 p.
Research subject Earth Science with specialization in Physical Geography
IdentifiersURN: urn:nbn:se:uu:diva-247641DOI: 10.1016/j.geomorph.2015.02.027ISI: 000355036000013OAI: oai:DiVA.org:uu-247641DiVA: diva2:797135