Icebergs
are made of freshwater ice and not of frozen sea water. They form
from the edge of glaciers when the glacier reaches the sea and either
break off in pieces to form an iceberg, or in the case of an ice shelf, begin to
float on the sea and then break off from the rest of the glacier as a
large slab.
Icebergs are made up of snow that has fallen
over many hundreds or even thousands of years. The stripes and different
coloured layers in icebergs represent different layers of snowfall and the
weather conditions under which the snow fell. If it is very cold then a
light open layer with much air included will be formed, this gives a paler
or white layer. The darker, bluer layers come from snow fall in relatively
warm, maybe even wet conditions when little or no air is trapped in the
layer.
In addition to this, air is squeezed out of the lower
layers of a glacier as more and more snow falls and so the weight of snow
builds up.
Paul
Ward - Pentax equipment, 50mm lens, 35mm film, K64.
This picture may not be copied or used in any manner without
prior written permission.
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