2008 Extended Continental Shelf Project

US Coast Guard icebreaker <em>Healy</em> and the Canadian Coast Guard icebreaker <em>Louis</em> S. St-Laurent side by side.

US Coast Guard icebreaker Healy and the Canadian Coast Guard icebreaker Louis S. St-Laurent side by side. Credit: USGS

In 2008, the U.S. Coast Guard Cutter Healy headed to the western Arctic Ocean for two cruises to map the seafloor of the continental shelf beyond 200 nautical miles. It was the fourth summer the U.S. collected data in support of defining its extended continental shelf in the Arctic Ocean, the others being 2003, 2004, and 2007.

The first cruise, August 14 to September 5, employed a sophisticated multibeam echo sounder that collected data to create a three-dimensional map of the Arctic seafloor north of Alaska in an area known as the Chukchi Borderland. The cruise was led by the University of New Hampshire's (UNH) Joint Hydrographic Center (JHC) with funding and scientific support from the National Oceanic and Atmospheric Administration (NOAA). Dr. Larry Mayer, UNH Co-Director of the JHC, was expedition Chief Scientist, and Capt. Andy Armstrong, NOAA Office of Coast Survey researcher and Co-Director of the JHC, was Co-Chief Scientist.

The first mapping cruise ended with a port stop in Barrow, Alaska on the 5th and 6th of September, after which Healy steamed north to meet Canadian Coast Guard ship Louis S. St-Laurent to continue mapping from September 6 to October 1. The Louis S. St-Laurent had left Kugluktuk on August 21 to collect data by herself before meeting Healy.

Healy mapped the seafloor as she did for the first cruise, but also created a straight and open path through the ice, while Louis S. St-Laurent followed, collecting seismic data using gear towed off the stern. The U.S. side of this cruise was led by the U.S. Geological Survey (USGS), with Jon Childs as Chief Scientist, while the Canadian side was led by Natural Resources Canada, with Dr. Ruth Jackson as Chief Scientist and Dr. Deborah Hutchinson of the USGS as chief USGS liaison. The collection of data took place under difficult circumstances due to varying weather and ice conditions, and towing the seismic sensors through the water in ice-covered conditions added to the complexity of the mission.

Healy returned to Barrow, Alaska on October 1 and Louis S. St-Laurent returned to Kugluktuk, Northwest Territories, on October 2.