Monitoring shorefast sea ice during spring whaling at Utqiaġvik
Since 2007, the University of Alaska Fairbanks, the North Slope Borough Department of Wildlife Management, and the Utqiaġvik whaling community have supported surveying and mapping of the community’s spring ice trails. This project was initially inspired by the efforts of Utqiaġvik elder Warren Matumeak and biologist Craig George to document the trails using GPS and hand-drawn maps in 2001.
Each spring, hunters route and build trails across the shorefast sea ice off Utqiaġvik to access hunting sites along the lead edge as they pursue the bowhead whale during its spring migration to the Beaufort Sea.
Trail locations are mapped using GPS. Ice thickness is surveyed along the trails using an electromagnetic (EM) conductivity meter mounted in a sled hauled behind a snowmachine.
The EM meter measures the strength of an induced electromagnetic field in the conductive seawater beneath the ice. The field strength serves as an indirect measure of ice thickness. This method allows ice thickness to be surveyed across large distances and the many ice types that make up Utqiaġvik’s shorefast ice, without the work of drilling holes in the ice.
These ice trail thickness surveys provide information about ice along specific sections of trail and reveal information about the local shorefast ice. Specifically, the surveys reveal the average thickness of level first-year shorefast ice, which is controlled by local freeze-up processes and timing, as well as weather, ocean, and ice conditions in the region throughout fall and winter.
For example, during this past spring (2018), the thickness of level first-year shorefast ice along the trails was just above 2.5 feet. By comparison, the thickness in 2017 was approximately 4.5 ft (see graph at right).
Trail maps (examples below) are provided to the community during the hunting season to inform hunting crews on trail locations. Mapped trails overlay the most recent synthetic-aperture radar (SAR) satellite image available to provide a resource for general ice type discrimination.
Maps are shared electronically and in paper form throughout the community in late April through early May.
For more information
Download community ice trail maps from 2007-2018.
Questions? Contact Matthew Druckenmiller, National Snow and Ice Data Center.
Related publications and resources
- Druckenmiller, M.L., H. Eicken, M. Johnson, D. Pringle, and C. Williams (2009) Toward an integrated coastal sea-ice observatory: System components and a case study at Barrow, Alaska. Cold Regions Science and Technology, 56 (1-2): 61-72
- Druckenmiller, M.L., H. Eicken, J.C. George, and L. Brower (2013) Trails to the whale: Reflections of change and choice on an Iñupiat icescape at Barrow, Alaska. Polar Geography, 36 (1-2): 5-20
- Northern Alaska Sea Ice Project Jukebox of the University of Alaska Fairbanks Oral History Program
- Ice trail thickness data for 2008-2012 available from NSF Arctic Data Center