HR: 16:00h
AN: C24A-01 INVITED     [Abstracts]
TI: Thaw Lakes in Continuous Permafrost: Recent Research and Controversies
AU: * Hinkel, K M
EM: Kenneth.Hinkel@uc.edu
AF: Department of Geography, University of Cincinnati, Cincinnati, OH 45221-0131 United States
AU: Frohn, R C
EM: Robert.Frohn@uc.edu
AF: Department of Geography, University of Cincinnati, Cincinnati, OH 45221-0131 United States
AU: Jones, B M
EM: bjones@usgs.gov
AF: Science Applications International Corporation, USGS, Alaska Science Center, Anchorage, AK 99508 United States
AU: Nelson, F E
EM: fnelson@udel.edu
AF: Department of Geography, University of Delaware, Newark, DE 19716
AU: Eisner, W R
EM: Wendy.Eisner@uc.edu
AF: Department of Geography, University of Cincinnati, Cincinnati, OH 45221-0131 United States
AU: Peterson, K M
EM: afkmp@uaa.alaska.edu
AF: Department of Biological Sciences, University of Alaska, Anchorage, AK 99508 United States
AU: Beck, R A
EM: RBeck@centralstate.edu
AF: Central State University, International Center for Water Resources Management, Wilberforce, OH 45384 United States
AB: Thaw lakes develop atop permafrost and, together with drained thaw lake basins (DTLBs), constitute the primary landscape elements on the Arctic Coastal Plain (ACP) of northern Alaska. Analysis of Landsat-7 ETM+ scenes indicates that there are 13,214 lakes and 6539 drained thaw-lake basins (DTLBs) on the western ACP, accounting for 20% and 26% of the 34,578 km2 study area, respectively. Thaw lakes have recently received considerable scientific scrutiny and press coverage. A paper by Smith and colleagues reported an increase in the number of lakes by 4% and a concurrent increase in total lake area by 12% in the continuous permafrost zone of western Siberia between 1973 and 1998. They attribute this to warming of permafrost, intensified thermokarst processes, and expansion of lakes. A report by Pelletier breaks with the long-standing interpretation that the orientation of thaw lakes on the ACP of northern Alaska is controlled by the predominant wind direction. Pelletier concludes instead that lake orientation is determined by the regional topographic gradient, and developed a model based on preferential thaw slumping of the downslope (lower) end of the lake basin. Although the processes associated with thermokarst, thaw lake evolution, and lake orientation are generally well understood, it is not clear how lake dynamics respond to climate forcing. This presentation reviews recent studies of thaw-lakes and DTLBs, and presents new data on shape and orientation metrics to estimate the relative influence of wind direction, landscape age, regional slope, local relief, distance from the coast, ground ice content and surficial sediments on lake morphometry. We also present an analysis of lake expansion and drainage on the Barrow Peninsula and western ACP of Alaska over the past 50 years.
UR: http://www.geography.uc.edu/~kenhinke/DTLB/HinkelWebFigs.ppt)
DE: 0700 CRYOSPHERE (4540)
DE: 0708 Thermokarst
DE: 0710 Periglacial processes
DE: 0746 Lakes (9345)
DE: 0758 Remote sensing
SC: Cryosphere [C]
MN: Fall Meeting 2005