title: Ice-sheet dynamics through the Quaternary on the mid-Norwegian continental margin inferred from 3D seismic data.
abstract: Reconstructing the evolution of ice sheets is critical to our understanding of the global environmental system, but most detailed palaeo-glaciological reconstructions have hitherto focused on the very recent history of ice sheets. Here, we present a three-dimensional (3D) reconstruction of the changing nature of ice-sheet derived sedimentary architecture through the Quaternary Ice Age of almost 3 Ma. An extensive geophysical record documents a marine-terminating, calving Fennoscandian Ice Sheet (FIS) margin present periodically on the mid-Norwegian shelf since the beginning of the Quaternary. Spatial and temporal variability of the FIS is illustrated by the gradual development of fast-flowing ice streams and associated intensification of focused glacial erosion and sedimentation since that time. Buried subglacial landforms reveal a complex and dynamic ice sheet, with converging palaeo-ice streams and several flow-switching events that may reflect major changes in topography and basal thermal regime. Lack of major subglacial meltwater channels suggests a largely distributed drainage system beneath the marine-terminating part of the FIS. This palaeo-environmental examination of the FIS provides a useful framework for ice-sheet modelling and shows that fragmentary preservation of buried surfaces and variability of ice-sheet dynamics should be taken into account when reconstructing glacial history from spatially limited datasets.
authors.affiliation: Scott Polar Research Institute, University of Cambridge, Cambridge CB2 1ER, UK.
authors.forename: A
authors.initials: A
authors.lastname: Montelli
authors.affiliation: Scott Polar Research Institute, University of Cambridge, Cambridge CB2 1ER, UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Dowdeswell
authors.affiliation: Geological Survey of Norway, Trondheim N-7491, Norway.
authors.forename: D
authors.initials: D
authors.lastname: Ottesen
authors.affiliation: Department of Petroleum Engineering and Applied Geophysics, Norwegian University of Science and Technology, Trondheim N-7031, Norway.
authors.forename: S E
authors.initials: SE
authors.lastname: Johansen
keywords: Fennoscandian Ice Sheet; Glacial geomorphology; Ice stream; Marine geology; Palaeo-glaciology; Seismic stratigraphy