HR: 16:00h
AN: C34A-01    [Abstracts]
TI: Ice Sheet Dynamics Along the Western Margin of the Scandinavian and Barents Sea-Svalbard ice Sheets on the Basis of Submarine Landforms
AU: * Ottesen, D
EM: dag.ottesen@ngu.no
AF: Geological Survey of Norway, Leiv Eirikssons vei 39, Trondheim, 7041 Norway
AU: Dowdeswell, J
EM: jd16@cam.ac.uk
AF: Scott Polar Research Institute, University of Cambridge, Cambridge, CB2 1ER United Kingdom
AU: Rise, L
EM: leif.rise@ngu.no
AF: Geological Survey of Norway, Leiv Eirikssons vei 39, Trondheim, 7041 Norway
AB: Morphological interpretation of regional and detailed bathymetric data sets (multibeam bathymetry and 3D seismics) on the 2,500 km-long Norwegian shelf from the North Sea (57N) to Svalbard (80N) has revealed a dynamic ice-flow pattern along the western margin of the north European ice sheets. About 20 cross-shelf troughs with megascale glacial lineations (MSGL) are interpreted as former pathways for fast-flowing ice streams. On intermediate shallower banks less dynamic ice probably existed. The two largest paleo-ice streams were the Norwegian Channel Ice Stream and Bear Island Trough Ice Stream, each 150-200 km wide at the mouth. The lengths of individual MSGL vary from hundreds of meters to several tens of kilometers, and the distance between ridges varies from 0.1-3 km. MSGL amplitudes reach 15 m, but are commonly less than 10 m. The onset of MSGL and, hence, fast ice flow is generally close to the outer coast, at the border zone between crystalline rocks and softer sedimentary rocks. Transverse submarine ridges on various scales, commonly parallel to the shelf edge, reflect either the maximum ice-sheet position or the recessional pattern of the ice sheet. Lateral ice stream moraines several tens of kilometers long have been mapped along the sides of several cross-shelf troughs, identifying the border zone between fast ice flow and stagnant or slow-flowing ice on intervening banks. An ice sheet model for the whole area during the last glacial maximum will be presented
DE: 3022 Marine sediments--processes and transport
DE: 3045 Seafloor morphology and bottom photography
DE: 1824 Geomorphology (1625)
DE: 1827 Glaciology (1863)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting