Write your abstract here. Birth of an Iceberg - Animated Movie.
This
animation, comprised of images acquired by Envisat’s Advanced Synthetic
Aperture Radar instrument, shows the breaking away of a giant iceberg
between September 2006 and October 2007 from the Pine Island Glacier in
West Antarctica. Spanning 34 kilometers in length by 20 kilometers in
width, the new iceberg covers an area nearly half the size of Greater
London. The European Space Agency launched ENVISAT on 1 March 2002, an
environmental satellite which uses Advanced Synthetic Aperture Radar
(ASAR), which can detect changes in surface height with a high degree
of accuracy. Several different processes can cause an iceberg to form, or
‘calve’, such as action from winds and waves, the ice shelf grows too
large to support part of itself or a collision with an older iceberg.
Since Pine Island Glacier -up to 2500 m thick with a bedrock over 1500 m
below sea level and comprises 10 percent of the WAIS- was already floating before it calved, it
will not cause any rise in the world sea level. Iceberg calving
like this occurs in Antarctica each year and is part of the natural
life cycle of the ice sheet.
A 34-year long study of the glacier has
shown that a large iceberg breaks off roughly every 5-10 years. The
last event was in 2001. Pine Island – the largest glacier in the
West Antarctic Ice Sheet (WAIS) – is of great interest to scientists
because it transports ice from the deep interior of the WAIS to the
ocean and its flow rate has accelerated over the past 15 years. The thinning caused the
glacier to retreat by over 5 kilometers inland, supporting the argument that
small changes at the coast of the Antarctic continent - such as the
effects of global warning - may be transmitted rapidly inland leading
to an acceleration of sea level rise. Although these long-term
regional changes are a cause for concern, the present iceberg calving
event does not in itself signal a significant change in the WAIS. Galaxy News Reported October 22nd, 2007.