With contributions from Ensign Erin Sheridan, Coast Guard Cutter Healy.
We last heard about the amazing men and women aboard Coast Guard Cutter Healy in January when they raced to re-supply fuel to the ice-encrusted harbor of Nome, Alaska. Not one to rest on their laurels, crewmembers are currently underway once again on a different – but just as important – mission. Healy is currently supporting scientific research in the cold, dynamic waters of the Arctic on their Arctic West Summer 2012 deployment.
Currently steaming so far north the sun never sets, watchstsanders and scientists are collaborating to collect vital scientific data. Just last week, Healy completed the second week of their extended continental shelf survey mission. This will mark the seventh year Healy has supported this particular mission.
Why is it important for Healy to take part in this mission? Well, only 11 percent of the Arctic Ocean has been bathymetrically mapped and 5 percent of the Arctic Ocean floor has been mapped by Healy’s crew. That means, of the approximately 540,000 square miles in the Arctic Ocean’s floor, Healy has surveyed 27,000 square miles!
The interest in mapping the continental shelf is based on the United Nations Convention of the Law of the Sea, allowing countries to claim mineral rights in areas where its continental shelf extends beyond the 200 nautical mile – 1 nautical mile is equal to 2,000 yards – exclusive economic zone.
In previous years, scientists were able to follow the North American continental shelf out to 500 miles north of Barrow, Alaska. During this year’s mission, scientists sought to find the edge of the slope in a more remote area, known as the Nautilus Basin.
Healy collects the high-resolution survey data from a special piece of equipment aboard their ship called a multibeam echosounder. As the ship steams along, the multibeam echosounder continually scans back and forth, perpendicular to the ship’s track. Within seconds, an area up to two miles wide is mapped onto the sonar’s monitor. As long as Healy drives slow, nearly straight and avoids thick ice floes that shake the ship and disrupt the beam, the swaths overlay each other evenly to form an unbroken image comprised of all the colors of the rainbow.
Red indicates shallower areas, whereas blue signifies deeper spots. As a result, the Nautilus Basin, where Healy has spent the last week and a half, is filled with crossing lines of color where before there was only vague contour lines. Thus Healy’s crewmembers coined this process with the phrase “Paint By Cutter.”
As the week came to a close, Healy exited the ice pack and headed south to conduct similar mapping around the Chukchi Cap. The bump and shimmy that defined Healy’s movement through ice pack was replaced by the pitch and roll of a long period swell. The sun also emerged for a rare appearance, causing the temperature to warm above freezing, melting most of the accumulated ice and snow. The most obvious sign of the sun’s presence – besides heavy squinting from the crew – was the sound of falling ice.
Want to read more? Follow along with Healy and crew with their weekly journal postings!