Polar Ice

[237SJ]

What causes the huge grey streaks which run parallel to each other on the ice that you see when you fly over Greenland/Antarctica?

[237SJ]

Whoops, I meant Greenland/the Arctic

[sddsddean]

Presumably you mean Glacial Moraine, Google it and find out all you ever needed to know.

[wildwood]

Pity you didn't mean Antarctica.... or the answer could have been algae. There is gray, green and red snow/ice there.

[237SJ]

sdd, I have googled and no, those pictures look nothing like what I mean. The steaks (more like smudges) that I have seen bear no resemblemce to rocks. They look like discoloured ice but they can`t be because they are too uniform in appearance.

[Andyvon]

I spent a week in East Greenland a few years ago following a two week tour of north east Iceland. Very little of the ice is white as people imagine. We visited a drill site on the ice cap by helicopter and also travelled down the coast to an Inuit village in a shrimp boat through ice fields and past massive icebergs.

Almost all the ice is coloured varying shades of blue and green - often in the most breathtaking of shades. There are many smudges and streaks in the ice which are different shades such as pink, green and red and that is formed by algae. When viewed close up most ice apears streaked and 'dirty' and those are areas of rock and gravel that the ice has collected during it's descent to the sea from the ice cap. Most icebergs take about 10,000 years to reach the sea and they collect debris from the surrounding terrain by rockfalls, wind, or by picking it up directly. Larger areas of ice are scarred by parallel crevasses which form when sheet ice flows over uneven terrain.

Greenland was the most beautiful and fascinating place I've ever been in my life.