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Glacial geology
Published in Barry G. Clarke, Engineering of Glacial Deposits, 2017
Glaciofluvial deposits lie unconformably on glacial tills, which may include tectonic structures and lenses of distinctly different materials contributing to a complex geological profile. Infrastructure projects may cross many glacial landforms making a geomorphological study an essential component of any ground investigation. In urban areas, the geomorphological profile may not be obvious, though it could be there and be significant. It is possible to classify the terrestrial landforms according to their mode and location of deposition (Table 2.10). The landforms may provide some indication of the glacial history; for example, transverse moraines, if formed during glacial recession, will be low-density non-sorted diamictons. The glacial soils forming these landforms may provide a further indication of the glacial history. A drumlin field is aligned with the direction of ice flow and, more importantly, raises the possibility of fissures aligned with the longitudinal axis of the drumlin, a problem for excavations in line with that axis. Some landforms are associated with highland glaciers so would not be expected in areas of plains of glacial soils. Table 2.11 summarises the principal landforms created by glacial deposition and their relation to the glacial environment. Table 2.12 lists the landforms typical of glaciofluvial soils. A summary of the major landforms is given here to demonstrate the complexity and diversity of these structures. The formation of glaciofluvial landforms is understood but recognising them can be challenging. The formation of subglacial landforms is still a matter of debate. In conclusion, geomorphological and geological studies of a region provide a valuable insight into the type of glacial material and therefore the geotechnical characteristics.
Geomorphological Studies from Remote Sensing
Published in Prasad S. Thenkabail, Remote Sensing Handbook, 2015
James B. Campbell, Lynn M. Resler
Glacial geomorphology is the study of geomorphological processes and resultant landforms and relief tied to glacier dynamics. Glacial dynamics have global relevance through their rapid response to climate change and resultant geomorphic impacts. Mountain glaciers are especially sensitive to climate variation, thus are considered to be a high-priority climate indicator (Kääb et al. 2005). Glacial landforms are often studied as proxies for past glacial activities (Smith et al. 2006) (Figure 12.3).
Drumlins in the Nordenskiöldbreen forefield, Svalbard
Published in GFF, 2018
Lis Allaart, Nina Friis, Ólafur Ingólfsson, Lena Håkansson, Riko Noormets, Wesley R. Farnsworth, Jordan Mertes, Anders Schomacker
Analyses of exposed subglacial landforms can give insight into past subglacial processes and ice dynamics. Glacial landform assemblages have been used to identify surge-type glaciers and distinguish those from landscapes and sediments produced by non-surge-type glaciers (e.g., Evans & Rea 2003; Kjær et al. 2008; Evans et al. 2009; Schomacker et al. 2014; Farnsworth et al. 2016; Ingólfsson et al. 2016; Ottesen et al. 2017).
Dynamics of a retreating ice sheet: a LiDAR study in Värmland, SW Sweden
Published in GFF, 2020
Alastair Goodship, Helena Alexanderson
The combination of LiDAR derived DEM and hillshade model analysis alongside field investigation of the study area has revealed a clear range of both terrestrial and marine glacial landforms. Features deposited within active and stagnant ice have been identified and linked to processes both sub-glacial and supra-glacial.