Mapping the extended continental shelf in the Arctic

Written by Petty Officer 3rd Class Lauren Steenson

Crewmembers aboard Coast Guard Cutter Healy prepare to deploy a dredge in the Arctic Ocean on Sept. 23, 2016. The dredge collected rock samples from outcrops of a seafloor canyon. U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Steenson.

Crewmembers aboard Coast Guard Cutter Healy prepare to deploy a dredge in the Arctic Ocean on Sept. 23, 2016. The dredge collected rock samples from outcrops of a seafloor canyon. U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Steenson.

Modern day explorers from the Arctic nations of Canada, Denmark, Finland, Iceland, Sweden, Norway, Russia, and the United States are setting their sights north to map the seabed and establish sovereign rights to resources in an icy area that just over a decade ago was virtually inaccessible.

Coastal nations have sovereign rights to ocean resources that extend 230 miles past the country’s coastline. Under the Law of the Sea treaty, coastal nations may also claim resources discovered if the extended continental shelf (ECS) of the nation extends past the 230-mile exclusive economic zone.

“The convention allows the opportunity for a coastal state to extend sovereign rights over its resources of the seafloor and sub-seafloor far beyond what every coastal state is entitled to,” said Dr. Larry Mayer, director of the Center for Coastal and Ocean Mapping. “The Law of the Sea Convention is basically a constitution for the oceans. In one article, just 617 words allow the redefinition of the continental shelf which allows a coastal nation sovereign rights of the seabed.”

Congress has charged Mayer and his team from University of New Hampshire’s (UNH) National Center for Coastal and Ocean Mapping with mapping the areas of the Arctic where the U.S. has potential rights to extend its continental shelf. He has worked closely with the U.S. Coast Guard since 2003 to have access to a platform capable of breaking and transiting through ice, while also supporting the scientific equipment needed to gather data on the ECS. The premier asset for the job is Coast Guard Cutter Healy, the service’s most technologically advanced polar icebreaker, homeported in Seattle, Washington.

“The Coast Guard has been an amazing collaborator in everything we’ve accomplished, and provided us with a spectacularly unique asset we are fortunate to have access to,” said Mayer. “When we first started, the Healy was one of the only icebreakers in the Arctic that used multi-beam sonar technology.”

During Mayer’s first cruise with Healy in 2003, they discovered a 10,000-foot high seamount approximately 400 miles north of Barrow, Alaska, which they named the Healy Seamount.

“This is our ninth trip to the Arctic. Four years in a row, we actually did a two-ship operation with the Canadian icebreaker Louis St. Laurent,” said Mayer. “They collected information which allows us to look deeper into the seafloor structure. Up until this year, they did not have the ability to map like we do with the multibeam sonar, so we worked together.”

Scientists aboard Coast Guard Cutter Healy monitor the depth of a dredge deployed off the back of the ship in the Arctic Ocean on Sept. 23, 2016. The computer screen shows a 3D model of the undersea cliff-face the dredge is retrieving samples from. U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Steenson.

Scientists aboard Coast Guard Cutter Healy monitor the depth of a dredge deployed off the back of the ship in the Arctic Ocean on Sept. 23, 2016. The computer screen shows a 3D model of the undersea cliff-face the dredge is retrieving samples from. U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Steenson.

The multibeam sonar is one of the key pieces of equipment scientists use aboard the Healy. Mayer described it as a very sophisticated echo-sounding system that puts together a 3-D picture of the seafloor that allows them to see if the seafloor meets the characteristics of the ECS.

On a computer screen, Mayer showed a three-dimensional, colorful image resembling a mountain range. The different colors correlate with the depth of the ocean. These mountains and canyons on the seafloor are what the multibeam sonar charts through the echo-sounding technology.

Over the past eight years of studying the Arctic seafloor, Mayer and his team have mapped more than 164,000 square miles of previously inaccessible waters. This summer, the destination was a previously mapped underwater valley to determine whether the canyon is part of the continental shelf.

“What we’re looking for is this big valley so we can dredge its steep walls,” said Mayer. “We’re going to drag a dredge, or a big, steel basket up the wall to try and break pieces of rock off to determine what it’s made out of. The dredge is actually for the Canadians mostly,” said Mayer. “Canada has collected seismic data for us (the U.S.) this year, so we are dredging and mapping for them.”

Scientists aboard Coast Guard Cutter Healy monitor the depth of a dredge deployed off the back of the ship in the Arctic Ocean on Sept. 23, 2016. The computer screen shows a 3D model of the undersea cliff-face the dredge is retrieving samples from. U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Steenson.

Crewmembers aboard Coast Guard Cutter Healy retrieve a dredge from the Arctic Ocean on Sept. 23, 2016. The Healy was on a five-month patrol in support of Arctic scientific research of the extended continental shelf. U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Steenson.

Just after a pink and orange sunrise over ice covered waters on Friday, Sept. 23, the bundled up Healy deck crew gathered on the fantail to deploy the steel dredge with a crane. The crane slowly lifted the chainmail basket off the deck, boomed it overboard, and lowered it into the trench of open water broken by the bridge team that morning.

In the aft conning room, the scientists kept their eyes on the depth and position of the dredge while the deck chief and first lieutenant monitored the safety of their crewmembers on deck.

The cable attached to the dredge was more than a 1/2 inch thick, but the resistance of pulling the dredge up a cliff face through the water tightens and stretches the cable like a bungee cord. If it were to break under strain, it could whip through anything in its path.

It was hours until they saw the dredge again. The scientists watched eagerly on deck in orange insulated suits waiting to dig through the muddy dredge basket like a Christmas present.

The first rock they uncovered was just bigger than a softball. After dumping the contents out on deck, they started sifting through on their hands and knees finding more small samples, enough to fill a five-gallon bucket.

Crewmembers and scientists aboard Coast Guard Cutter Healy empty the contents of dredge on deck to find rock samples in the Arctic Ocean on Sept. 23, 2016. The scientists recovered several rock samples from the mud. U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Steenson.

Crewmembers and scientists aboard Coast Guard Cutter Healy empty the contents of dredge on deck to find rock samples in the Arctic Ocean on Sept. 23, 2016. The scientists recovered several rock samples from the mud. U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Steenson.

Then the equipment was reset, and the entire process was completed again. By evening, the deck crew had executed another successful dredge which yielded further valuable rock samples for the science members to study.

“We recovered rocks from both dredges, which is great. It turned out very successful,” said Mayer. “The mission was very constrained, but everyone has bent over backward to mitigate weather and time challenges.”

He said that weather, ice, and distance are always the challenges faced when operating in the Arctic.

“We had some key mapping targets we’ve worked hard to accomplish. The dredge was a very high priority item for international collaboration,” said Mayer. “We had no guarantees with the dredge, but we’re coming back with two successful dredges, so we lived up to our end of the cooperative agreement, and the Canadians fulfilled theirs with the data they’ve collected.”

The overarching goal of both the Canadian mission and the U.S. mission is to establish the limits of the ECS by determining the shape of the seafloor, thickness of the sediment, and the nature of the rocks. The mapping, seismic data, and dredging operations are pieces of the puzzle to determine if the limits of the ECS can be extended.

“Scientists are always greedy, as time on this ship is so valuable,” said Mayer. “How often does anyone get up to an area like this to collect information? We know so little about the Arctic; we want every little bit of information we can get.”

A scientist aboard Coast Guard Cutter Healy holds up a rock sample from the Arctic extended continental shelf, Sept. 23, 2016. The rock was broken off the undersea cliff-face by the deployed dredge. U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Steenson.

A scientist aboard Coast Guard Cutter Healy holds up a rock sample from the Arctic extended continental shelf, Sept. 23, 2016. The rock was broken off the undersea cliff-face by the deployed dredge. U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Steenson.

All the collected samples will be delivered to the U.S. Geological Survey, the official curator of the samples. Then they are sent to Canada, or made available to Canadian scientists, to determine the nature of the rocks and ECS.

The ECS for the U.S. and Canada are very close together, if not overlapping. The bottom line is that it is so challenging to work in the Arctic, Mayer said. Pooling resources and coordinating research with our neighbor saves both countries a tremendous amount of cost and effort, and that’s why we can work together and share information.

“It’s rewarding on many levels. It’s a feeling of serving your country in a sense, since we’re doing something on behalf a national mission,” said Mayer. “It’s also one of the most unexplored places in the world, so we are truly explorers mapping places that have never been mapped before and taking samples from things that people have no idea what it’s made of.”

Healy’s commanding officer, Capt. Jason Hamilton, agreed with Mayer that it is a privilege to serve the United States at the end of the planet. Hamilton said, “The Healy crew is honored to act as the backbone for groundbreaking science, providing presence and access throughout the Arctic to execute Coast Guard missions, project national sovereignty, and fulfill our treaty obligations.”

The overall attitude of this mission has been bittersweet between the excitement of exploring and researching the unknown, and the reality of why ships are now able to access areas this far north. Receding Arctic ice is opening up the area to additional claims to resources via the ECS, as well as increased commerce, transit, and touring. The need for precautions, protection, and safety of life at sea and ecosystem is paramount in the years to come.

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