HR: 12:05h
AN: C32A-08    [Abstracts]
TI: Thermokarst Distribution in the Noatak Basin, Alaska: Increased Frequency and Correlations with Local and Regional Landscape Variables
AU: * Balser, A W
EM: Andrew.Balser@uaf.edu
AF: Institute of Arctic Biology University of Alaska Fairbanks, IAB, 311 Irving I University of Alaska Fairbanks, Fairbanks, AK 99775, United States
AU: Bowden, W B
EM: Breck.Bowden@uvm.edu
AF: Rubenstein School of Environment & Natural Resources University of Vermont, Rubenstein School of Environment & Natural Resources University of Vermont, Burlington, VT 05405, United States
AU: Jones, J B
EM: ffjbj@uaf.edu
AF: Institute of Arctic Biology University of Alaska Fairbanks, IAB, 311 Irving I University of Alaska Fairbanks, Fairbanks, AK 99775, United States
AU: Gooseff, M N
EM: mgooseff@engr.psu.edu
AF: Engineering Department Pennsylvania State University, Civil & Environmental Engineering Department Pennsylvania State University 212 Sackett Bldg., University Park, PA 16802, United States
AU: Sanzone, D M
EM: diane.sanzone@bp.com
AF: ARCN - National Park Service, National Park Service 4175 Geist Road, Fairbanks, AK 99709, United States
AU: Bouchier, A
EM: abouchie@mines.edu
AF: Colorado School of Mines, Colorado School of Mines 1500 Illinois St., Golden, CO 80401, United States
AU: Allen, A
EM: aallen@mbl.edu
AF: Institute of Arctic Biology University of Alaska Fairbanks, IAB, 311 Irving I University of Alaska Fairbanks, Fairbanks, AK 99775, United States
AU: Allen, A
EM: aallen@mbl.edu
AF: Brown University, Brown University, Providence, RI 02912, United States
AB: In arctic regions, climate warming is leading to permafrost melting and wide-scale ecosystem alteration. A prominent pathway of permafrost loss is through thermokarst processes, which includes the catastrophic loss of soil structure and rapid subsidence. Regional-scale distribution of thermokarst features is poorly documented throughout the arctic, and correlations with landscape variables is not well understood. The Noatak Basin in northwestern Alaska's Brooks Range mountains harbors a transitional landscape from arctic and alpine tundra to boreal forest within a 7,000,000 acre watershed. Field investigations augmented by photogrammetric measurements from 2005 to 2007 revealed patterns in the distribution of classifiable thermokarst failure types in the Noatak Basin, and provided data on the physical and chemical impacts these features have on aquatic systems. Distinct thermokarst classes show significant relationships with local site variables such as slope and vegetation, and with regional variables including lithology, glacial geology and landcover. Frequency of thermokarst features has increased markedly in several core study areas in the Noatak Basin within the past 30 years. Analysis of current and historical aerial photographs shows two to three fold increases in number of features present, and in total surface area of landscape affected. The core study areas are spread along a gradient from the upper to lower Noatak Basin covering a number of major land cover types. The majority of these features occur in headwaters of Noatak tributaries and can have marked impacts on small headwater streams, which have less capacity to buffer the effects of disturbance. These studies show that thermokarst processes and effects, especially in headwater regions, have been vastly under-reported in the Noatak Basin. These findings suggest that similar phenomena may be under-reported in other permafrost regions as well, due in part to the logistical difficulty of conducting quantitative surveys in remote areas with rugged topography.
DE: 0702 Permafrost (0475)
DE: 0718 Tundra (9315)
DE: 0744 Rivers (0483, 1856)
DE: 0758 Remote sensing
SC: Cryosphere [C]
MN: 2007 Fall Meeting