GIS analysis as a tool for identification of preglacial large-scale landform assemblages and quantification of glacial erosional impact on northern shields
2013 (English)In: 8th International Conference (IAG) on Geomorphology Abstracts Volume, 2013Conference paper, Poster (Refereed)
The use of quantitative assessment methods in large-scale bedrock geomorphology remains scarce. Yet analysis and integration of DEMs with other digital data in GISs now allows us to rapidly analyze landform assemblages and patterns across huge areas.
I analyze areas within the glaciated Fennoscandian shield to investigate preglacial landform patterns as well as to assess the effects of glacial erosion on the preglacial shield surface. Analyses of all data available from land surveys and geological surveys in Fennoscandia are the input parameters in the database. In the DEMs of 50m and 25m resolution, hypsography, relative relief and slope angles show preglacial landform patterns like stepped erosion surfaces and inselberg clusters that are not visible on first sight and that are difficult to detect and show only by field work or other forms of remote sensing. Integration of these patterns with rock type and structure helps us to assess the influence of geology on the surface morphology. Slope angles and bedrock types are statistically coupled to drill core databases with bedrock depth information. This 3D terrain analysis enables a picture of surficial glacial streamlining and the removal of the preglacial weathering mantles, and thereby assessment and comparison of different degrees of glacial modification of the shield bedrock surface.
In combination with field validation, DEMs and GIS analyses have brought us much further in identifying patterns of glacial erosion as well as quantifying glacial erosion depth on the shield surface. We find clear defined areas with negligible erosion in proximity to areas with clear glacial streamlining. However, even in areas of strongest glacial erosion, the preglacial large-scale bedrock landscape prevails. Comparison of these areas infers that maximal glacial erosion of shield bedrock was in the 0-50 m range, with extensive areas showing <10 m of erosion.
Place, publisher, year, edition, pages
Research subject Geography, Physical Geography
IdentifiersURN: urn:nbn:se:su:diva-104040OAI: oai:DiVA.org:su-104040DiVA: diva2:720129
8th International Conference (AIG) on Geomorphology, "Geomorphology and sustainability", Paris, August 27-31, 2013