Will the Opening of the Northwest Passage Transform Global Shipping Anytime Soon?
With the melting of Arctic Ocean ice, the fabled waterway between Europe and Asia has been open to shipping the past two summers--or has it?
GOING WITH THE FLOE: Here is one of the buoys that Bruno Tremblay deploys on the ice in the Canadian archipelago. Instruments like this send hourly data on their location via satellites to Tremblay. These ice mass balance buoys also measure internal ice temperature, ice thickness and position as well as, in future, internal stresses in the ice that tell scientists how much stress it can take before it starts to break. All this data will ultimately be used to validate models of sea ice, a tool that is decidedly lacking in the Arctic. To date, Tremblay has four such buoys deployed and plans to install an additional three each year for the next five years.
Currently, any ship traversing the Northwest Passage is best kept abreast of its chances by checking out daily sea ice maps, which are based on satellite images. In the future, however, sea ice models could be used to forecast ice conditions for vessels. Researchers are also perfecting radar systems for ships that are specialized for detecting sea ice. Robert Magee
STILL AN ICY DRINK: Despite rapid warming in the Arctic Ocean, one of the reasons the Northwest Passage won't be safe for ships anytime soon is the stubborn persistence of thick multiyear ice in the area. These maps show the presence of multiyear ice in the area over the month of September. Notice how there is just slightly more multiyear ice this year compared with 2007.
Even when ice retreats from this region, it is replaced by multiyear ice that flows in from the Queen Elizabeth Islands to the north. As long as multiyear ice exists on these islands, it will find its way into the passage. "These processes aren't just going to stop," says Stephan Howell, a climatologist at the University of Waterloo's Interdisciplinary Center on Climate in Ontario. "As long as there's ice in the Arctic Ocean it's still going to drain through."
LIQUID HIGHWAY: Despite this past summer being the second-lowest on record for sea ice cover in the Arctic, the most direct route through the passage remained dotted with ice floes. This satellite image from mid-August 2008 shows the direct route through the Northwest Passage as a solid orange line. The orange dotted line shows the southern route through the passage, which was passable for almost a month this year, as it had been for the past three summers.
MASSIVE MELTDOWN: Arctic sea ice cover reached its minimum extent on September 14 2008 [
see image]. The average sea ice cover for the month of September was 1.80 million square miles (4.67 million square kilometers). This marked the second-lowest sea ice extent that satellites have recorded since they began measurements in 1979 as well as a one-third reduction in sea ice cover compared with the 1979 to 2000 average. NASA
PRIMEVAL PASSAGE: Although the northern route through the Northwest Passage has only opened twice since records have been kept, research suggests that it did become passable from time to time in the last 10,000 years.
Art Dyke, a paleogeographer with the Geological Survey of Canada, studies the remains of bowhead whales along the passage to infer the minimum sea ice extent in the Canadian Arctic over the past 10,000 years. So far he and his colleagues have recovered the remains of some 1,200 animals from marine deposits that have risen above sea level because of crustal rebound following the last glaciation.
Bowhead whales follow the edge of the sea ice as it retreats north in the summer. "Each year they map out the migration of the ice edge," Dyke explains. Given the distribution of bowhead whale remains across various sections of the passage, Dyke has inferred that the sea ice retreated far enough in the past to leave the passage open.
"The minimum amount of summer sea ice for postglacial times is centered around 9,000 to 8,000 [years] before present," he says. "There have been times in the past prior to any anthropogenic warming when we've seen sea ice conditions that are perhaps rather similar to what we've seen in the last two summers," he says.
Here is a photo of a bowhead whale skull with attached mouth and jaw (maxillary) bones excavated from raised beach gravel on northwestern Baffin Island.
STRAIT THROUGH: Here is a satellite image of the McClure Strait, which lies along the direct northern route through the Northwest Passage. This section of the passage is normally clogged with ice, hindering transits through the area by smaller vessels. In 2007, however, it cleared up, rendering the northern route negotiable.
NORTHERN EXPOSURE: The most direct route through the Northwest Passage (orange line) opened up last year. (The path which did not clear, is depicted by the blue line.) As opposed to the other, more southern, routes through the passage, this northern one is more direct and deeper, making it attractive to freighters in search of a shortcut between Europe and Asia.
This was the second time in recent history that the northern route was reliably navigable. There was also a brief period when it opened up in 1998--which was the Canadian Arctic's record lowest year of ice cover.
Ice-free areas are shown in dark gray, whereas iced areas are green.
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