Comments on: Icebergs – Global Warming or Local Cooling? http://www.herkinderkin.com/2010/01/icebergs-global-warming-or-local-cooling/ Musings of a grumpy old man Fri, 08 Jul 2011 13:45:00 +0000 hourly 1 http://wordpress.org/?v=3.1 By: JJ http://www.herkinderkin.com/2010/01/icebergs-global-warming-or-local-cooling/comment-page-1/#comment-27 JJ Wed, 03 Mar 2010 19:47:32 +0000 http://www.herkinderkin.com/?p=483#comment-27 On the face of it, they are unrelated, in the sense that the glacial flow is ice formed by compressed snow. Glacial flow is related to snowfall over a period of years, for that is the source of glaciers. Sea ice forms when the sea is cools enough for it to form - simple as that. In the Arctic, where the North Pole is in the middle of the sea, sea-ice can persist for years. The South Pole is close to the middle of Antarctica, an island continent nearly as big as Australia, and the sea-ice around the rim is almost wholly seasonal. Most of it disappears in the summer and it reforms in the winter. As it warms and thins in the summer, wave-motion cracks it and it breaks up into vast floes. Unlike glacial icebergs, which calve off the face of glaciers as they reach the sea, the floes are flat. The icebergs seen off the coast of NZ last year are of this type - huge ice floes. Having said that, the presence of thick sea-ice at the mouth of a glacier can inhibit calving for years, so that the glacial flow juts out from the mouth, sometimes so consolidated that it survives the summer melt of the sea-ice. When it finally calves, either from its own weight or from the impact of a floating iceberg, it can create a super-iceberg. That is the type of iceberg reported this year. On the face of it, they are unrelated, in the sense that the glacial flow is ice formed by compressed snow. Glacial flow is related to snowfall over a period of years, for that is the source of glaciers. Sea ice forms when the sea is cools enough for it to form – simple as that. In the Arctic, where the North Pole is in the middle of the sea, sea-ice can persist for years. The South Pole is close to the middle of Antarctica, an island continent nearly as big as Australia, and the sea-ice around the rim is almost wholly seasonal. Most of it disappears in the summer and it reforms in the winter. As it warms and thins in the summer, wave-motion cracks it and it breaks up into vast floes. Unlike glacial icebergs, which calve off the face of glaciers as they reach the sea, the floes are flat. The icebergs seen off the coast of NZ last year are of this type – huge ice floes.

Having said that, the presence of thick sea-ice at the mouth of a glacier can inhibit calving for years, so that the glacial flow juts out from the mouth, sometimes so consolidated that it survives the summer melt of the sea-ice. When it finally calves, either from its own weight or from the impact of a floating iceberg, it can create a super-iceberg. That is the type of iceberg reported this year.

]]> By: Steve A Morris http://www.herkinderkin.com/2010/01/icebergs-global-warming-or-local-cooling/comment-page-1/#comment-26 Steve A Morris Wed, 03 Mar 2010 18:23:11 +0000 http://www.herkinderkin.com/?p=483#comment-26 Do we know if the increase in sea ice attributed to the flow of glaciers or is the sea ice formation unrelated to glaciers? Do we know if the increase in sea ice attributed to the flow of glaciers or is the sea ice formation unrelated to glaciers?

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