The Way of an Iceberg Photos and words by Dennis Minty

Greenland Icecap

Imagine you are standing on the icecap of Greenland perhaps 10,000 years ago. Snow is falling. The cold is penetrating. In fact, over a full the year, it's so cold that the snow accumulates faster than it melts, hence the icefield grows.

A glacier meets the sea, northern Greenland

If you could live long enough, you would see the icefield thicken and spread. Where the outer edge of the icefield meets with lower ground, the ice creeps down-hill as a "glacier". This slow-moving ice river gradually slips down through a valley eventually meeting the sea where a thick overhang forms that becomes undercut by the sea - a "tide-water glacier". Some glaciers melt away before reaching the sea. They don't produce icebergs.

Pressure from the moving ice uphill, wave action from the sea and warm temperatures in the summer causes the ice to break off in an explosive event called "calving".

An iceberg begins its journery

Finally an iceberg is born about 10,000 years after the snow fell around your feet.

Once floating, its sea journey begins. The icebergs that calve into the waters off west Greenland first float north carried by the dominant current. As they reach the north end of Baffin Bay, they are swept westward into Canadian waters, picked up by the southward flowing current and gradually move down the coast of the arctic islands, Labrador and eventually reach Newfoundland. The full journey might take 2 or 3 years with the bergs freezing into the icepack each winter.

Iceberg and fishing boat off St. Anthony, Newfoundland

About nine out of ten icebergs that reach Newfoundland waters, in the area known as "iceberg alley", come from west Greenland, while one out of ten is from the Canadian arctic.

Grounded iceberg, St. Anthony, Newfoundland

Once in the warmer waters, the icebergs melt and eventually disappear, but this is not a quiet and gentle process like the melting of the ice-cube in your summer libation. With most of the iceberg (80-90%) underwater, the submerged part generally melts faster than that above the waterline. As the ice melts, the centre of gravity changes disrupting the forces holding the berg together. It can begin to shift its position in the water, first tipping, then rocking and sometimes rolling over entirely. Often an explosive breakup accompanies this event with great chunks of ice blown into the air and shards falling back into the sea as though the iceberg was just hit by the shell of a giant cannon. The whole process is called "foundering". You can be standing on land many kilometres from an iceberg, but, with the tell-tale, thunder-like boom, you know it has foundered.

Large, grounded iceberg.

Many of the icebergs are so large that they become grounded even in water that is 10s of metres deep. They sit in this position until they melt away or breakup further and then drift off again. The Grand Banks off Newfoundland is anywhere from 15 metres to 90 metres deep and icebergs have scoured the bottom leaving a network of criss-crossing trenches as though ploughed by a drunken farmer.

Melt water lines in an iceberg.

Sometimes you see an iceberg with remarkable, turquoise lines. They might be a few centimetres wide or even a metre or more. These generally form when surface water on the glacier runs into a crack, filling it with water. When that water refreezes, it has no air in it, unlike the surrounding body of the glacier that contains a lot of air. After all, the glacier formed from snowflakes being squeezed into solid ice with lots of air trapped inside.

Iceberg texture showing bubble tracks.
Iceberg texture showing bubble tracks.

The detailed texture of an iceberg surface can be fascinating. Often a series of narrow, parallel furrows appears as though the berg has been scraped by a set of teeth or prongs. Sometimes these can be drag marks where the underside has been scratched by the sea bottom, but they can also be bubble tracks that form as the air in the iceberg escapes below the waterline and rises in straight lines to the surface. Over time, many together etch the parallel tracks into the ice.

Blue iceberg, west Greenland

Some icebergs are mostly blue. As the ice builds up in a glacier, the bottom layers are so highly compressed by the weight of ice above that the air is squeezed out. This ice will appear blue because there are no air bubbles left in it. When you see this, you know you are looking at very old ice from near the bottom of the glacier.

Blue ice bear looks to the sky.

Iceberg season in Newfoundland and Labrador begins in March and April and can continue late into the summer. The number of icebergs varies immensely from year to year, but 2017 is shaping up to have a bumper crop.

Humpback whale with iceberg

Photos and Words by Dennis Minty

Evening sun radiates from an iceberg in northwest Greenland.

One of the best ways to experience the journey of an iceberg is on a trip with

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Dennis Minty
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Photos © Dennis Minty

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