HR: 1340h
AN: GC33A-0955    [Abstracts]
TI: Erosion of the Barrow Environmental Observatory Coastline 2003-2008, Northern Alaska
AU: * Aguirre, A
EM: aaguirre3@miners.utep.edu
AF: Systems Ecology Lab, Department of Biology and the Enviromental Science and Engineering Program, The University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968, United States
AU: Brown, J
EM: jerrybrown@igc.org
AF: International Permafrost Association, P.O. Box 7, Woods Hole, MA 02543, United States
AU: Gaylord, A
EM: nunatech@usa.net
AF: Nuna Technologies, P.O. Box 1483, Homer, AK 99603, United States
AU: Tweedie, C E
EM: ctweedie@utep.edu
AF: Systems Ecology Lab, Department of Biology and the Enviromental Science and Engineering Program, The University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968, United States
AB: There is concern that the rate of erosion to Coastal bluffs in the arctic could increase as the duration of ice-free near shore waters also increases. The Barrow Environmental Observatory (BEO,) a coastal research reserve of 7500 acres is bounded on the east by the 11-km long Elson Lagoon shoreline. Rates of erosion to these 2 to 5 m high ice- and organic- rich permafrost bluffs have been monitored at key sites on an annual basis since 2003 as part of the Arctic Coastal Dynamics (ACD) program. Foot surveys using a survey-grade Differential Global Positioning System (DPGS) with centimeter vertical and horizontal accuracy were conducted along the entire length of the BEO coastline in August 2003, 2006 and 2007. The mean erosion rate during the 2003-06 period was 2.69 meters per year. In summer 2007, two DGPS surveys were conducted, one in June before ice breakup and the second in August late in the summer season. The June survey provides a baseline for summer 2007 measurements and will serve to document the rate of erosion between the August 2006 survey and subsequent freeze-up of Elson lagoon during the 2006-07 winter. Detailed characterization of the coastal bluff was also made in summer 2007. At every 100m along the coastal bluff, photographs of the bluff were taken and the steepness of the bluff was measured. Bathymetric measurements were collected using a high-velocity depth sounder along transects parallel and perpendicular to the coastline and up to 2km in to Elson Lagoon. Ongoing analysis is measuring the rate of erosion between each of the measurement periods and estimating the corresponding volumetric loss of bluff soil to Elson Lagoon. We are also identifying in detail, sections of coastline where the rate of erosion is differing and using these to ascertain the relative importance of offshore bathymetry, orientation of the coastline to dominant winds and the physical characteristics of the coastal bluff to the rate of erosion measured. The central goal of this paper is to report and interpret changes in inter-seasonal erosion and to update the record of long-tern erosion measurements for this section of arctic coastline.
DE: 0706 Active layer
DE: 0740 Snowmelt
DE: 1694 Instruments and techniques
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting