Once fast ice (sea-ice frozen in situ and attached
to the coast) has become established, the patterns of the earlier
pieces disappears. The tide still rises and falls however meaning
that the sea surface expands and shrinks slightly as it does so.
Tide cracks are a result of this movement (as ice is not known for
its elastic properties) they are formed when the ice moves apart,
they close again when the tide falls. A tide crack is often many
miles long, in this case stretching for around 5 miles (8 kilometres),
but never more than about 18", 45cm wide between Signy and Coronation
Islands in the South Orkneys group.
Tide cracks are valuable resources
for wild-life as they provide a region where birds such as snow
petrels can fish through for krill and also as a breathing hole
for crab eater and Weddell seals.
Paul Ward - Pentax equipment,
50mm lens, 35mm film, K64.
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or used in any manner without prior written permission.