Retreat pattern and dynamics of glaciers and ice sheets: reconstructions based on meltwater features
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Glaciers and ice sheets covered extensive areas in the Northern Hemisphere during the last glacial period. Subsequently to the Last Glacial Maximum (LGM), they retreated rapidly and, except for Greenland and some other ice caps and glaciers, they vanished after the last glacial termination. This thesis examines the dynamics of deglacial environments by analysing the glacial geomorphological record with focus on the landforms created by glacial meltwater. The aims are (i) to evaluate the data available for mapping glacial meltwater features at the regional scale, and (ii) to demonstrate the potential of such features for regional ice retreat reconstructions in high-relief landscapes. Meltwater landforms such as ice-marginal meltwater channels, eskers, deltas and fossil glacial lake shorelines are used to infer former ice surface slope directions and successive positions of retreating ice margins.
Evaluated high-resolution satellite imagery and digital elevation models reveal their potential to replace aerial photographs as the primary data for mapping glacial meltwater landforms. Following a methods study, reconstructions of the deglacial dynamics are carried out for central Transbaikalia, Siberia, Russia, and for the Cordilleran Ice Sheet (CIS) in central British Columbia, Canada, using regional geomorphological mapping surveys.
Mapped glacial landforms in central Transbaikalia show evidence of a significant glaciation that possibly extended beyond the high mountain areas. Large glacial lakes were formed as advancing glaciers blocked rivers, and of these, Glacial Lake Vitim was the most prominent.
Deglacial dynamics of the CIS reveals that the ice divide shifted to the Coast Mountains in north-central British Columbia and the eastern ice margin retreated towards the ice divide in late glacial time.
This thesis demonstrates the potential to reconstruct ice retreat patterns and deglacial dynamics at regional scales by interpretation of the meltwater landform record.
Place, publisher, year, edition, pages
Stockholm: Department of Physical Geography and Quaternary Geology, Stockholm University , 2012. , 17 p.
Dissertations from the Department of Physical Geography and Quaternary Geology, ISSN 1653-7211 ; 30
Palaeoglaciology, Cordilleran Ice Sheet, deglaciation, glacial meltwater features, glacial lake
Research subject Physical Geography
IdentifiersURN: urn:nbn:se:su:diva-68958ISBN: 978-91-7447-429-9OAI: oai:DiVA.org:su-68958DiVA: diva2:474287
2012-02-10, De Geersalen, Geovetenskapens hus, Svante Arrhenius väg 14, Stockholm, 13:00 (English)
Jansson, Krister, DocentStroeven, Arjen, ProfessorKleman, Johan, ProfessorHelmens, Karin, Docent
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Submitted. Paper 6: Manuscript.
List of papers