Analyzing Trends in Iceberg Coverage in Disko Bay, West Greenland Using Optical Satellite Imagery

Abstract:

Recent changes in ice discharge from the Greenland Ice Sheet have increased the flux of icebergs to the adjacent ocean, with consequent impacts on freshwater flux, ecosystems, and shipping. In Disko Bay, West Greenland, changes in the flow regime and calving behavior of Jakobshavn (Ilulissat) Isbræ have altered the size and distribution patterns of icebergs, though how these changes manifest beyond the fjord sill where they impact coastal navigation has not yet been quantified. Satellite coverage of this area is relatively frequent, but manual analysis of iceberg coverage in each image is prohibitively time consuming. We are developing an algorithm to automatically delineate icebergs in optical imagery and provide detailed information about their size and location. Preliminary analysis of selected Landsat images suggests that the size distribution of icebergs in Disko Bay has changed over the course of the past decade, shifting towards an increasing number of smaller icebergs.