Drilling for facts about Beaufort Methane Leaks

Edmonton Journal  Sun Apr 29 2012
By Margaret Munro
Postmedia News

The oil and gas industry may be eyeing the energy riches under the Arctic Ocean, but scientists are even keener to start drilling.

They say the Beaufort Sea, in the western Canadian Arctic, holds clues to several environmental mysteries of global significance – chief among them why so much methane, a potent greenhouse gas, is now seeping out of the sea floor.

An international team is proposing an ambitious drilling program to extract some answers. Researchers from Canada, the United States, Europe and Korea want to drill wells from the Mackenzie Delta across the Beaufort Sea.

If approved, drilling could begin as early as 2015, the first holes bored into the Canadian Arctic in years.

The Integrated Ocean Drilling Program, an international outfit that dispatches research ships around the world, has reviewed the preliminary plan and recently asked the scientists to submit a full proposal, says Anne de Vernal, at the Université du Quebec a Montreal, chair of the committee overseeing Canada’s involvement with IODP.

She and her colleagues say the Beaufort is the best place in the Arctic to assess the stability of undersea permafrost and gas deposits and to fill in big gaps in climate science. They want to drill down through sediments that have rained onto the sea floor over eons, revealing how the Arctic ice has waxed and waned, and into the thick slabs of permafrost and frozen gas beneath the sea floor that have the potential to accelerate global warming.

The operation would also be “a good first step” toward Arctic drilling as the scale would be small compared with what the energy industry envisions, says Pierre Francus, at Quebec’s Institut National de la Recherche Scientifique. He is on the executive committee of the International Continental Scientific Drilling Program, which is considering backing the project with the IODP.

Although “a lot less risky” than drilling for oil and gas, the proposed scientific drilling would require environmental assessment and approval from federal and Inuvialuit authorities, Francus says.

The shallow waters that fringe the Arctic are among the most dynamic and understudied part of the world’s oceans, says geologist Scott Dallimore, at Natural Resources Canada, co-leader of the planned project. The waters – 30 per cent of the Arctic Ocean – cover continental shelves that run more than three million square kilometres along the north coasts of North America and Siberia.

Permafrost hundreds of metres thick occurs on the shelves, and has been slowly warming since the end of the last ice age. As the slabs warm, they can destabilize the sea bed, generating underwater landslides that send sediments barrelling down from the continental shelf into the deep ocean.

One landslide, discovered by Natural Resources Canada scientists in the Beaufort, left more than 200 square kilometres of sediments strewn across the deep sea floor.

More worrisome to many observers is the massive store of methane sitting beneath the permafrost in the form of gas hydrates. The gas has been trapped under the sea for thousands of years, but there is mounting concern – and evidence – that it is leaking out as the climate warms.

In the last few years, dramatic plumes of methane have been spotted by teams surveying waters off Siberia. A Canadian-U.S. team has also found “extensive free gas release” on the Beaufort Shelf, which is pockmarked with holes the escaping gas leaves behind. At one spot about 50 metres below the surface, the team’s remotely operated vehicle found gas “vigorously and continuously” bubbling out of a sea mound, kicking up clouds of sediments.

The chemical signature of the methane seeping from the Beaufort Sea floor – gas that has been locked under the sea for at least 50,000 years – indicates much of it is bubbling up through cracks and gaps in the permafrost, Dallimore and his colleagues report.

How much methane is entering the atmosphere, and whether the rate is increasing as Arctic ice retreats and the climate warms, isn’t known. But scientists say it is important to find out because methane is 20 times more potent as a greenhouse gas than carbon dioxide is.

The permafrost and vast hydrate deposits in the shallow Arctic waters pose “a potentially significant geohazard and may release vast amounts of methane to the atmosphere,” geologist Matt O’Regan, at Cardiff University in Britain, says in a report outlining the “urgent need” for the scientific drilling.

The plan is to drill as many as 10 wells, up to 650 metres deep. They would run from the Mackenzie Delta out several hundred kilometres offshore to where the Beaufort Shelf drops into the deep waters of the Canada Basin.

Along with assessing the permafrost and escaping gas, the researchers say the drilling could answer questions about climate changes of the past.

European scientists on the team want to solve the mystery of why the Northern Hemisphere abruptly cooled off about 12,800 years ago.

Many believe a deluge of melt water from North America’s massive glaciers at the end of the last ice age swept down the Mackenzie River and was responsible for the sudden cold snap, known as the Younger Dryas, that lasted about 1,200 years. Sediments on the floor of the Beaufort could provide proof, scientists say.

The sediments could also reveal how polar ice has come and gone over the ages, and help refine predictions of how the Arctic, and global climate, might behave in future.

“We do not know when the pack ice developed in the Arctic Ocean,” de Vernal says. “This is one of the rare places in the Arctic where the answer is there. We know it is there, but we have to drill, and drill at the right place.”

This fall, Scott Dallimore of Natural Resources Canada plans to head to the Beaufort with U.S. and Korean scientists to start surveying for drill sites. They intend to return in 2013 with Korea’s state-of-the-art icebreaker, the Aaron, to complete the survey. The detailed project plan will then be submitted and reviewed by the international drilling programs, which are funded by governments around the world, and the researchers hope drilling can start in 2015.

The international drilling programs would pick up most of the estimated $15-million cost, but the researchers are game to collaborate with industry.

At a recent workshop on the proposal, they say industry agreed to share data amassed during exploratory drilling operations in the Beaufort in the 1970s and ’80s.

“It’s not a case of scientists doing industry’s work, more a case of working together to understand these environments,” Dallimore says.

Illustration:
• Supplied / South Korea’s polar research vessel and icebreaker the Aaron, shown here plying Antarctic waters last year, will cruise into Arctic waters in 2013 to help scientists select the best places to drill in the Beaufort Sea. They will probe the Beaufort seabed to see how the ice has waxed and waned over thousands of years.

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