Amazing Striped Icebergs
Posted by Syed Aslam on May 6, 2008
Amazing isn’t it ?? Icebergs in the Antarctic area sometimes have stripes, formed by layers of snow that react to different conditions. Most of those in the Antarctic were formed from snow falling on the giant ice sheet that covers the continent. Over time, the snow is compressed to form more ice, which slides slowly towards the sea.
There it either breaks off into the water, or forms an ice shelf. Most appear white as a result of the tiny bubbles trapped within them which scatter light in every direction. However, if the bubbles are squeezed out, or if part of the iceberg melts and quickly refreezes, it can appear blue.
Blue stripes are often created when a crevice in the ice sheet fills up with melt water and freezes so quickly that no bubbles form. When an iceberg falls into the sea, a layer of salty seawater can freeze to the underside. If this is rich in algae, it can form a green stripe.
Brown, black and yellow lines are caused by sediment, picked up when the ice sheet grinds downhill towards the sea.
Only one-tenth of an iceberg lies above the water. The biggest known iceberg towered 551ft above sea level - the height of a 55-storey building.
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