HR: 1340h
AN: C23A-0988    [Abstracts]
TI: An Integrated Geoscience Assessment of the Influence of Geologic Processes and Climate on the Permafrost Environment of the Mackenzie Delta, N.W.T.
AU: * Wright, F
EM: fwright@nrcan.gc.ca
AF: Geological Survey of Canada, Box 6000, Sidney, BC V8L 4B2 Canada
AU: Dallimore, S
EM: sdallimo@nrcan.gc.ca
AF: Geological Survey of Canada, Box 6000, Sidney, BC V8L 4B2 Canada
AU: Dallimore, A
EM: adallimo@nrcan.gc.ca
AF: Geological Survey of Canada, Box 6000, Sidney, BC V8L 4B2 Canada
AU: Taylor, A
EM: ataylor@nrcan.gc.ca
AF: Geological Survey of Canada, Box 6000, Sidney, BC V8L 4B2 Canada
AU: Nixon, M
EM: mnixon@nrcan.gc.ca
AF: Geological Survey of Canada, Box 6000, Sidney, BC V8L 4B2 Canada
AU: Solomon, S
EM: ssolomon@nrcan.gc.ca
AF: Geological Survey of Canada, Box 6000, Sidney, BC V8L 4B2 Canada
AB: The Mackenzie River delta of Canada's Northwest Territories is characterized by some of the most complex permafrost conditions in the Arctic. Within a 400 square kilometre area of the outer delta, permafrost varies from less than 80m to over 600m in thickness. This variability in both permafrost thickness and ground temperature conditions is dictated by significant variations in the history of surface temperatures caused by the interplay between climatic effects and variations in large-scale geologic processes. During the past 100,000 years the geothermal regime of this area has been influenced by glaciation, long periods of sub-aerial exposure, periods of marine transgression/regression, fluvial deposition, coastal erosion, and lake development and drainage. This paper will introduce an integrated geoscience approach to the assessment of permafrost and related geotechnical considerations in the Mackenzie Delta. A key objective of the research was establish constraints to the late Quaternary history of the area by utilizing shallow core samples collected from lacustrine, deltaic and shallow marine environments. The current variability in annual temperature regime of aquatic environments was assessed through the deployment of small ground temperature loggers in lakes, ponds and river channels. Shallow ground temperatures were also available from a variety of terrestrial observation sites. An assessment of the paleo-temperature regime was undertaken through terrain mapping and coring of contemporary lake basins to constrain the history of lake formation and drainage. These data served as a basis for geothermal modeling to determine the theoretical distribution of permafrost in this area.
DE: 1823 Frozen ground
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting