UNIVERSITY OF ALASKA FAIRBANKS
Alaska Arctic Observatory & Knowledge Hub: Community-based observations of changes in the seasonal cycle in Alaska's Arctic

Monitoring shorefast sea ice during spring whaling at Utqiaġvik

Warren Matumeak (upper left; photo by Shari Fox) created the first known maps of Utqiagvik’s ice trails in as hand drawn maps in 2001 (example in upper right). A map of the 2001 ice trails was reconstructed based on the collection of Warren’s sketches.

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.

Oliver Dammann pulling the EM meter along an ice trail in spring 2015.

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).

Thickness distribution of shorefast sea ice along trails used by Utqiaġvik hunters. (Source: EM surveys between 3-8 May 2017 and 27 April to 3 May 2018)

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

Utqiaġvik ice trail maps from Spring 2018 with hunting crew locations (above, left) and ice thickness values along the trails (above, right).