Ice is everything in Greenland. It has been there for millions of years, and has been the most significant influence in shaping Greenland’s landscape, history and culture, and still has a direct bearing on life here. The island is dominated by Greenland’s Icecap, more than 2 miles thick and the second biggest in the world, covering almost 2 million square kilometres.
If this icecap were to melt, sea levels would rise around the world by 20 feet. Glaciers derived from the icecap flow to the coast and carve out the remarkable mountain ranges that form Greenland’s coasts. These extend right down to the sea at the heads of dramatic fjords where they discharge their loads as giant icebergs of all sorts of fantastic shapes, sizes and colours. Greenland produces the most icebergs of anywhere in the world, and it is one from here that sunk the Titanic.
Icebergs
Since they were derived from inland glaciers, icebergs are made entirely of fresh water, and the average age of the ice is thought to be about 15,000 years. Typically only one-fifth to one-seventh of the iceberg can be seen above the water's surface. Their ice is rock hard, and the 'bergs are of all shapes and sizes, sometimes rising hundreds of feet above sea level. Eventually icebergs make their way out to the open ocean where they drift southwards into the Atlantic. They begin to crumble under the strength of the summer sun and rising temperatures further south, and produce a great many 'bergy bits' and 'growlers'.
Sea Ice
Also called 'pack ice', this is another different type of ice. It forms from frozen seawater, as its name suggests, not compacted snow. Sea ice is dynamic and forms in stages, with different names for each stage. It changes with the seasons, and being at the mercy of currents and winds, it is almost always on the move.
Sea ice forms when the temperature of the ocean surface falls below -1.89 Celsius. Unlike the calm surface of a lake, where ice forms in a gradually thickening sheet, the ocean surface is frequently stirred by waves. This leads to some interesting forms of ice. In turbulent water, tiny disc-shaped crystals of ice form into a substance called frazil. As they are stirred through the sea surface, the crystals give the water a greasy appearance, hence the name 'grease ice'. Another form that sea ice takes as it grows is shuga, composed of small chunks of ice that undulate on the surface of the water in a sheet. When the ice clumps together, it forms rounded sheets with upturned edges, called pancake ice. The pancakes damp down the waves somewhat, allowing pancakes to consolidate into larger pancakes. Eventually, the pancake ice freezes into floes - larger sheets of sea ice floating on the water's surface.
There are two types of pack ice: first-year ice and multi-year ice. First-year ice freezes in autumn or early winter and melts in the summer. Typically, first-year ice is between a foot to six feet thick. Multi-year ice is simply pack ice that has survived at least one winter. A smaller fraction of the polar sea ice grows along shorelines and in enclosed bodies of water such as bays. This is called lastfast ice.Sea ice is dynamic in another sense: It is alive. Far from being a frozen wasteland, floating pack ice is laced with creatures living in a complex food web.
Importance of sea ice
Once frozen, fjords become important highways and Inuit hunters move up and down them by dog sled, returning to favourite spots where the hunting’s good and seeking out new ones. In Greenland there are always new places to explore. Dog sleds allow enormous distances to be covered relatively easily and so the winter ice was, and still is, crucial in terms of keeping the far-flung settlements of Greenland connected. Today, rising temperatures make for less reliable ice conditions, and the ice lasts for a shorter time, compromising the hunter's ability to find food. This is a direct threat to the Inuit way of life.
Ice explains East Greenland’s isolation. The icecap, hundreds of miles wide, is impenetrable for most and the huge stream of Polar ice and icebergs, the Great Ice, that flows southwards on currents along the coast bars access from the east. In North and East Greenland, whilst ice has allowed a community to thrive, it has also kept it hidden from the rest of the world, even from the rest of Greenland, and allowed ancient skills and traditions to flourish.
Follow the story of one of Greenland's icebergs and its journey from its birth high on the icecap, to its plunge into the frigid seas of Greenland’s coast.