Measuring mountains under the sea

Anything can happen out on the Arctic Ocean where extreme weather and ice conditions wreak havoc with the best-laid plans.

That’s what an international team of Canadian and Danish scientists are discovering the hard way, as they race against time to complete a major mapping project of the Arctic Ocean seabed.

The goal: to show that the structure of the undersea Lomonosov Ridge is an extension of the North American continent.

If Canada and Greenland can scientifically prove this, they will claim control over the slope and the seabed well beyond the normal 200 nautical miles from shore. Both countries are eager to stake their claim to this potentially resource-rich area.

This month, a team of about 30 is camping out at the Canadian Forces base in Alert and on the ice north of Ellesmere Island and Greenland.

So far, fog, wind and rough ice conditions are hampering efforts to map the underwater lay of the land.

The Lomonosov Ridge lies about 1,000 metres below the sea-surface. A mountain chain, 50 to 70 kilometres wide, it stretches 1,500 km across the top of the world — from Greenland to Siberia. The ridge is named after Mikhail Lomonosov, an 18th century Russian scientist.

Canada and Denmark are in a hurry to show that this ridge is attached to the boundary of North America.

That’s because, under the United Nations Convention on the Law of the Sea, which covers seabed claims, Canada must submit all of its supporting scientific evidence for undersea claims by 2013 and Denmark, by 2014.

Russia is also in the middle of an extensive seismic mapping effort to support its own claim to the Arctic seabed.

“If you have good geological arguments and you go to the commission [on the law of the sea], and you say ‘and by the way we agree,’ you simplify their lives,” said Dr. Ruth Jackson of the Geological Survey of Canada.

Jackson, the Canadian team leader, spoke to Nunatsiaq News before heading off to Alert in March.

The joint Canada-Denmark project is called LORITA, for the “Lomonosov Ridge Test of Appurtenance” (“appurtenance” means “thing that is connected”). Canada is putting more than $30 million into the project.

LORITA has nothing to do with the disputes between the two countries over Hans Island, because there, the island lies in the Nares Strait, which is only 27 km wide.

“[Hans Island] is not a law of the sea issue. That’s a boundary dispute,” Jackson said.

But if Canada and Denmark can claim the Lomonosov Ridge as a natural prolongation of their territories, they will exercise the right to explore and exploit mineral and biological resources on and below the seabed and have jurisdiction in matters related to the environment and conservation.

To show that the ridge is indeed part of North America, the scientists are using explosives. As these are set off, shock waves are produced. Radar then picks up the waves, and the picture these create determines what the seabed looks like. Using explosives are the only way to do this, because the ice is too thick to penetrate with other sound-generating equipment.

“You can’t get a nuclear ice-breaker in there,” Jackson said.

This is why the team is drilling holes down through the ice and putting pre-molded explosives in the holes. The charges dangle 100 m below the ice surface, where they’re detonated.

“To make a sound, there’s no other way to do it,” Jackson said.

Three lines covering 200 km from end to end are being laid, along with a cross line. Explosive experts plan to set a total of 11 charges, while 150 instruments set 1.5 km apart are recording the echoes.

“The ice is in constant motion, and we’re trying to get a straight line if possible,” Jackson said.

The ice near the mouth at Nares Strait moves down the strait, so everything — laying the charges, exploding them and then picking up the instruments — has to be done in a rush.

“We don’t want to leave these things on the ice,” Jackson said.

Operations are based in Alert with a small emergency camp for safety, fuel and explosives storage and a landing strip. This camp had to be set up about 30 nautical miles farther north than originally planned due to ice conditions.

A Twin Otter and three helicopters transport equipment and people from Alert. Dave Malloley, former operations manager at the Polar Continental Shelf in Resolute Bay, is coordinating all the project’s logistics.

To date, despite delays in the arrival of people, equipment and helicopters to Alert, as well as fog, wind and incredibly rugged ice conditions, scientists have managed to place a portion of charges and instruments out on the ice.

Each of these instruments has a seismometer connected to batteries and a recording unit to store the data. They’re stored in a “cooler” and “icepacks” to keep them warmer than the frigid air.

A decision was made earlier this month to detonate some of the charges along the southern portion of one line, because weather to the north was supposed to worsen.

“It has been a day spent in a race with incoming bad weather, and in this race there has been no clear winner. Although we do have data, we do not have as much as we had planned,” notes the project’s web site.

The thickness of the ice in that part of the Arctic Ocean means no marine mammals are affected by the detonations.

Keeping an eye on the project is Jobie Kiguktak from Grise Fiord. Kiguktak is accompanying the flights over the ice, checking for ice conditions and for any random seals or polar bears.

LORITA is supposed to wrap up in early May. In the meantime, the team provides updates on its web site at http://a76.dk/lang_uk/main.html.