Retreat pattern and dynamics of glaciers and ice sheets: reconstructions based on meltwater features

Retreat pattern and dynamics of glaciers and ice sheets: reconstructions based on meltwater features
Martin Margold

Department of Physical Geography and Quaternary Geology Stockholm University

© 2012 Martin Margold ISSN: 1653-7211 ISBN: 978-91-7447-429-9 Paper I © 2012 Taylor & Francis Paper II © 2011 Journal of Maps Paper III © 2011 Journal of Maps Paper IV © 2011 Elsevier Printed by Universitetsservice US-AB, Stockholm, Sweden

Doctoral dissertation 2012 Department of Physical Geography and Quaternary Geology Stockholm University

ABSTRACT 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 highrelief 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 regional mapping surveys including the glacial meltwater system. Following a methods study, reconstructions of the deglacial dynamics are carried out for the area of 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