The Concrete Sea

The concrete sea

"Now we are in the very midst of what the prophets would have had us dread so much. The ice is pressing and packing round us with a noise like thunder. It is piling itself up into long walls, and heaps high enough to reach a good way up the Fram’s rigging: in fact it is trying its utmost to grind the Fram into powder."

Norwegian Fridtjof Nansen, 1893 ...stuck in Arctic pack ice

The concrete sea 1 "The eastern Arctic will melt sooner than the west. When you look at a chart you will see the many islands in the eastern Arctic. They can also act as a barrier or restrict the flow of multi-year Arctic pack. But if the ‘Ice Dams’ do not form before the freezing temperatures set in, multi-year ice will drift south. This type of ice can be found along the Labrador and Newfoundland coasts during the winter navigation season. The western Arctic has a more moderate climate in the summer but quickly changes by late September and ice will form before the eastern Arctic.

You will find the same types of ice in both regions. There will be more multi-year in the Beaufort Sea, particularly in the high latitudes (north of 76 degrees latitude). Lately I have found that the pack ice in the western Arctic stays close to the Canadian Arctic Archipelago."

Captain Andrew McNeil, St Louis Icebreaker CCG 2009

The concrete sea 2 Average thickness is more than two metres, but can vary. Ice that's just forming is only a few millimetres, much older ice or where ice is crushed together can be tens of metres. The Canadian Archipelago average thickness is six to eight metres.

The concrete sea 3 Storms and rough seas can cause the floating sea ice to collide and crush together to make jumbled blocks of ice or pressure ridges. The depth of ice below water is known as the keel depth, and the height of ice in the air is called sail ice.

The concrete sea 4 The Arctic Ocean is the smallest of the worlds oceans covering 1,405,6000km2.

In the winter it’s so cold the water freezes (salt water freezes at a lower temperature than fresh water) at -1.8 degrees Celsius. The frozen seawater floats freely in the ocean, moved by wind and water currents. It is called drift ice and when it joins together it’s called pack ice, layers of frozen water. Large chunks of drift ice are called ice floes – and can measure up to 9.7 kilometres across.

The concrete sea 5 Winter sea ice in the Arctic is up to 2.5 metres thick. The thickness of the ice is calculated "from the time it takes a radar pulse to travel from a satellite to the surface of the ice and back again" (NERC).

Sea ice has different stages of development, related to thickness and age. By age there are two distinctions: first year ice, and multiyear ice.

First year ice: thicker than 30 centimetres but melts in the summer season.

Multiyear ice: survives the summer melt, reforms and gains in thickness: 2 to 4 meters thick.

The ice cap is shrinking by 33,800 sq km per year.

The concrete sea 6