Wednesday, August 5, 2009

PS 47-68: Erosion rates along arctic coastlines in the Barrow Environmental Observatory, Barrow, Alaska, 2003-2008

Adrian Aguirre1, Craig E. Tweedie1, Jerry Brown2, and Allison Gaylord3. (1) University of Texas at El Paso, (2) International Permafrost Association, (3) Nuna Technologies

Background/Question/Methods

Erosion rates along high latitude shorelines are among the highest in the world. With changing climatic conditions the vulnerability of arctic shorelines is increasing as a consequence of longer exposure to ice free seas. Communities, industry, marine and terrestrial ecosystems along coastal arctic regions are being heavily impacted by these rapid changes. The Barrow Environmental Observatory is bounded on the east by the Elson Lagoon shoreline of the Beaufort Sea. Rates of erosion along bluffs have been monitored annually at 14 transects since 2002 as part of the Arctic Coastal Dynamics program. Continuous, ground-based Differential Global Positioning System surveys were conducted along the BEO shoreline in 2003, 2006, 2007 and 2008.


Results/Conclusions
The mean erosion rate for the five-year period is at 2.3 meters per year. This analysis shows erosion occurring most during the fall periods (August 2006 – June 2007, 8121 m2 and August 2007-June 2008, 13806 m2) in comparison to summer erosion rates (June 2007-August 2007, 7933m2 and June 2008- August 2008, 6438 m2).  The total area lost to erosion during the five year period was 11.8 hectares (2.4 ha/yr) which has remained consistent with the 2007 rates (2.5 ha/yr) but is almost double the rate (1.3 ha/yr) calculated for the period 1979-2000 by previous studies.