||November/December 2000 issue||
In the November/December 2000 issue
of Canadian Geographic, Dane Lanken takes readers to Canada’s
most northerly community, Alert, on the northern tip of Nunavut's
Ellesmere Island. Read "On Alert" to find out how the
military listens in on its neighbours and monitors sea traffic,
and click other headings for more.
At the top of Ellesmere Island, Canada’s military listens in on the neighbours and perfects the art of
‘hearing’ sea traffic
By Dane Lanken with photography by Janice Lang
On Alert |
Northern Shortcut |
Alert facts |
Alert in brief |
CLEAR SKIES, NO WIND. The working conditions are perfect. It might be -35°C, but that is
an advantage when conducting experiments in oceanacoustics. The intense cold creates vast tracts
of solid, motionless ice that allow investigators to listen in a way that wouldn’t be
possible in more temperate climes. For this very reason, a team of scientists fiew to the northern
tip of the most northerly island in Canada’s Arctic Archipelago last spring to dip their
microphones through holes in the ice and see how sounds fare and fade in the farthest reaches
of the Arctic Ocean.
|Cpl. Ken Forsyth contemplates the glistening
vista at Alert as he transports equipment back from an ice camp set up for scientists.
Rebel is one of two sophisticated all-terrain vehicles delivered, like everything else
at the Canadian Forces station, in a Hercules aircraft.
The researchers’ destination was a dot on the north coast of Ellesmere Island called
Alert or, to be more formal, Canadian Forces Station Alert. It is roughly 4,000 kilometres
— or eight hours of engine roar in a Hercules cargo plane — north of Canada’s southern
cities, about 2,000 kilometres from the nearest tree and just 817 kilometres of frozen ocean
away from the geographical North Pole. Set up exactly 50 years ago as a joint Canadian-American
weather station, Alert instantly became the northernmost permanently established community
on Earth. Its nearest neighbour is Thule, Greenland, 676 kilometres to the south, where there
is both an Inuit community and a large U.S. air base.
of the scientists who travel to Alert are civilian employees of Canada’s Defence Research
Establishment, a branch of the Department of National Defence. They are charged with creating,
among other things, the hardware the military needs to guard Canada’s coasts. Listening
devices in the ocean, which date back to at least the Second World War, are much cheaper
and sometimes more effective than shipboard or even aerial surveillance. They have long been
vital in detecting prowling alien submarines and are now finding new uses catching ships
that try to avoid radar and photographic detection while carrying illicit drugs or illegal
immigrants. So many countries maintain such eavesdropping systems that when an explosion
racked the Russian submarine Kursk last August, "everybody," as one Canadian researcher
put it, "knew about it right away."
The possibility that global warming will result in much easier navigation through the Northwest
Passage in the next decade or two is once again bringing into focus concerns about sovereignty,
security and search and rescue in the Far North. And it is giving new urgency to ocean acoustics
investigators working to improve remote listening capabilities — particularly the behaviour
of sound in and under ice in the Arctic Archipelago, which routinely ranges in thickness
from one or two metres to 10 or more.
When the military arrived at Alert in 1958, the station, which is closer to Moscow than
Ottawa, became an important listening post for Cold War eavesdropping, something it remained
after the Americans left in 1970 and remains today, even if the Cold War has cooled. The
operations section of the main complex, devoted to "signals intelligence," is outfitted
with shredding machines and is off-limits to all but those with top security clearance.
In spite of Alert’s central military role, it has always accommodated certain scientific
endeavours: weather and ozone-layer observations, wildlife and plant studies, geological
and continental-shelf investigations and, since the 1970s, ocean acoustics. Last spring,
for instance, a party of 17 scientists and technologists - most from the Defence Research
Establishment in Halifax, along with a few of their counterparts from Ottawa - headed north
for a month of High Arctic experiments. They had the sense to arrive in mid-March, when it
was still cold but the sun had reappeared after a five-month absence. Within a couple of
weeks, old Sol was hovering day and night along the northern horizon, providing sunlight
24 hours a day.
Their acoustics trials were complicated, highly precise and, for the layperson, not a little
abstruse. The general aim was to explore how sound travels through different combinations
of water and ice, to determine how to locate sound sources and to zero in on specific sounds
while tuning out background noises. In certain regions of the Arctic Ocean, the ice cracks
and grinds as it is moved about by wind and currents, and animals add to the din as they
go about their daily lives: whales creak and moan; seals click. Still, Arctic waters are
a great deal quieter than temperate oceans, in which the clang of countless ship engines
causes an unceasing racket. And the waters around Alert are particularly quiet.
Just before each test, the scientists shut down their generators and began running their equipment
and computers off several dozen car batteries. Lastly, they stopped talking and sat very still,
with their feet raised off the ground. "It was usually only for five minutes at a time," says
Garry Heard, head of the acoustics team and a veteran polar researcher, "but after a few
hours of that, everyone was getting fidgety."
|At a camp outside
Alert, scientist Ron Verrall(LEFT) of Canada’s Defence Research Establishment tries
to stay warm as Stan Dosso of the University of Victoria drills a hole for a seismic
One experiment involved creating a sound at a fixed underwater location — popping
light bulbs was a favourite method - then picking up the noise with a series of underwater
microphones called hydrophones at another fixed position under the ice. By comparing
their calculations based on the collected data to the known location of the sound,
the scientists could test the system’s accuracy.
Why light bulbs? "They’re a nice clean source," says Heard, "clean
in sound and clean environmentally. We used to use explosives, but they are much
more intrusive. Now we put a light bulb in a little frame, lower it on a steel cable
about 30 metres, then send a piece of pipe down to pop the bulb. All you end up with
is a little extra silica on the sea floor."
In another test, the researchers used a sledgehammer to hit wooden posts that had
been frozen into ice and picked up the noise with a wide array of solid-surface microphones
known as geophones. This seismic exercise allowed them to determine the speed and
intensity of sound through different types of Arctic ice. This far north, the ice
varies from smooth, relatively thin one-year pans to compressed multi-year agglomerations
tens of metres thick. In addition to its covert listening applications, this research
might eventually enable pilots to determine the thickness and nature of ice from
an airplane just by dropping a geophone — a boon to cold-weather navigation.
Indeed, the latter commanded roughly half of the scientists’ time at Alert
last spring. Work over the past few years had produced a dart-shaped sonobuoy called
Icepick, which, when dropped from a plane, sticks into the ice and sends back any
sounds it hears. However, a problem of orientation remained.
The metre-high Icepick could relay a particular noise — say, the swish of a submarine’s
propeller - but it could not ascertain its direction. To impart this ability, the researchers
had to provide the sensor with a compass-like device for use in high-latitude regions,
since regular compasses don’t work in the High Arctic. They did this with a couple
of off-the-shelf global positioning system (GPS) units, which use satellites to pinpoint
the holder’s precise location on Earth. Two units were fitted into the Icepick
just a finger’s length apart, but this was enough — a monument to the efficacy
of the GPS — to give bearings relative to one another and, therefore, to determine
the angle at which the sonobuoy landed and the direction of the noise. "It is
fortunate it works," says Heard, "and it is amazing."
Gebauer uses a communications cable to talk to the pilot of a Hercules transport
The scientists conducted all of last spring’s acoustics experiments
at a makeshift camp about 10 kilometres from Alert. Using snowmobiles and sleds,
they hauled out and back several tonnes of equipment, including a hot-water
drill to make holes in the ice, generators, batteries, banks of computers and
seven tents with plywood fioors.
While some of the team slept back at Alert, with its private rooms, dining
hall and lounge, others preferred the solitude and serenity of the ice camp.
Among the latter was scientist Ron Verrall, who e-mailed home rhapsodically
about working until midnight, with the sun still shining, the air so still
that smoke rose straight from the tent chimneys and the temperature a crisp
-44°C. "It was all very pretty," he recalls.
A cable-controlled underwater vehicle called the Phantom was also hauled to the
camp. The Phantom was just a little thing, about a metre wide and a metre and
a half long, with two on-board video cameras, a 600-metre control cable and remotely
operated "hands" that arranged the lines and hydrophones during underwater
trials. It was a far more modest vessel than its predecessor, Theseus, a remote-controlled
yellow submarine built for the Defence Research Establishment in Victoria and
used in a joint American-Canadian acoustics experiment in 1996. Here, a slim
two-millimetre-thick fibre-optic cable was laid on the sea fioor between Alert
and a hydrophone array under the ice an astonishing 180 kilometres away. The
experiment was successful - the cable was laid, the sub returned - and a new
technique proved capable of allowing shore-bound researchers to study under-ice
noise and sound propagation. The name Theseus was the obvious choice, given that
the Greek hero of that name slew the Minotaur at the heart of a labyrinth and
found his way out again by means of a thread he had laid behind him.
in the semi-darkness of early spring, a weather building at Alert has a
certain eerie beauty. plane.
Generally, the work of the Defence Research Establishment precedes by a decade
or two any actual application by the military. But because of global warming
and its apparent effect of thinning Arctic ice, some of the acoustics research
conducted last spring might find use much sooner.
"Indications are that the northern basin will change faster than other
areas," says Jim Kennedy, head of underwater acoustics at Defence Research
in Halifax. "A more navigable Northwest Passage is part of the reason
there has been a resurgence of interest in Arctic efforts. It has to do with
responsibility for maintaining sovereignty, and one way to demonstrate sovereignty
is to know what’s going on."
"In other words, use it or lose it," adds Garry Heard. "Sovereignty
is a concern. We work up there, so in some small way, we contribute to it."
Dane Lanken is a contributing editor to Canadian Geographic. Janice
Lang is a photographer with the Defence Research Establishment in Ottawa.
For the complete history of Alert, check out Alert,
Beyond the Inuit Lands: The Story of Canadian Forces Station Alert by
David R. Gray (Borealis Press).
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