The birth of an ice island is rarely seen. But what begins in remote high Arctic latitudes can, in the years and decades that follow, have a real impact on places that are far more visible, like shipping lanes and offshore oil platforms.
Recent years have produced a wave of ice islands. Researchers tracking the giant formations have tabulated roughly 1,000 square kilometres that have broken free from Greenland and Canada's Arctic islands. At a time when new research suggests the Greenland ice sheet is melting five times faster than in the 1990s – and roughly a quarter of that is in the form of icebergs, according to the Swiss Federal Research Institute – a frozen area the size of Hong Kong is wandering south, breaking into hundreds and thousands of smaller bits, some too small to be seen by ship radar, as they drift.
That volume of ice stands to present hazards to marine industries along Canada's northern and eastern coasts for years to come, researchers are now warning. Ice islands, especially if they stay in northern latitudes, can last for decades as they slowly splinter apart, so the potential for problems is a lengthy one.
Roughly half the volume has come from the coast of Ellesmere Island, at the top of the Arctic archipelago.
"These are ice islands that are drifting to the west, and will be of concern for any infrastructure or shipping in the western Arctic," said Derek Mueller, an assistant professor in the department of geography and environmental studies at Carleton University, who studies icy regions. He referred specifically to revived offshore drilling in Alaska and to rising, albeit still minimal, levels of traffic through the Northwest Passage.
The Greenland ice is headed into better-travelled transatlantic shipping lanes. A large section of one ice island has already found its way near the Strait of Belle Isle, between Labrador and Newfoundland, a shortcut used by vessels crossing between northern Europe and the St. Lawrence.
"If they break up into smaller pieces and you get bergy bits and growlers" – concrete-hard chunks the size of houses and cars, some of which can be submerged in heavy wave conditions, making them difficult to spot – "they're impossible to track at that scale," Mr. Mueller said. "So any one of those pieces of ice could potentially be a hazard to shipping."
Some of that risk can be avoided by mapping the trajectory of ice islands, a task that has become part of Mr. Mueller's research. He has worked with Transport Canada and the Canadian Ice Service to predict where the ice islands will go and how they will deteriorate – modelling the path of danger. He and several other researchers will present an update of their findings to an Arctic research gathering in Vancouver next week.
The concern about ice islands must be weighed against the tremendous gains that have been made in ice detection in recent years and decades. The ice services of the Canadian and U.S. Coast Guards produce regular ice maps that are widely available to ship captains. Companies engaged in oil exploration pay close attention to icebergs, using satellite data and spotter planes to track their movements – and employing ships to tug them away if they near production platforms.
Those ships, however, can't redirect a large fragment of an ice island, although "for the most part these ice islands are breaking up into small enough fragments that by the time they get south, they're manageable," said Tony King, director of geotechnical engineering with C-CORE, a St. John's firm that does ice engineering work.
Vessels sailing into the St. Lawrence are not required to have ice strengthening. The marine industry says that, while ice is always a concern, it is not worried about an invasion of ice islands. Most traffic passes below Newfoundland – a minority uses the Strait of Belle Isle – and with warming air and seas, "I don't think [ice islands] would really go south of the southern tip of Newfoundland, which then doesn't really impede navigation," said Jean-François Belzile, director of marine operations for the Shipping Federation of Canada.
In 2010 and 2011, about 5,900 ships passed through the Gulf of St. Lawrence, according to Innovation Maritime, a Quebec research centre.
Not even the full extent of modern technology has kept ships fully clear of icy danger. Brian Hill spent most of his career studying ice and ships, most recently with National Research Council. He has assembled a database tabulating 560 incidents between ships and icebergs dating back to 1810. Even today, there are one or two incidents a year in the northern hemisphere, he said. Some are serious: In 2000, a shrimp trawler sank off Happy Valley- Goose Bay, Labrador, for example.
His study of history shows that large chunks of ice have historically travelled directly into shipping lanes south and east of Newfoundland – including the area where oil platforms like Hibernia are stationed.
That said, the number of icebergs floating south intact has diminished, and ice islands have been rare relative to the past – like in 1890, when mariners reported 129 sightings of floating ice greater than 300 metres in length. It's clear that "we just don't get anything like that" today.
Besides, the recent production of ice islands is in some ways a last gasp. Between 1906 and 2005, 90 per cent of Ellesmere Island's ice shelves vanished, according to Mr. Mueller. There aren't a lot more places left to birth ice islands.
The flip side: As shipping in the Arctic increases, more vessels are placing themselves in the path of danger.
"You're never really going to get rid of ice up there, so any vessel going up there is putting itself at risk one way or another," Mr. Hill said.