First discovered in 1955, and named to mark the work done by airmen to open up the Antarctic continent, the Aviator Glacier is a major valley glacier descending from the plateau of Victoria Land along the west side of the Mountaineer Range. It enters the sea at Lady Newnes Bay, where it forms a floating ice tongue that extends into the water for about 25 kilometres.

This Envisat Advanced Synthetic Aperture Radar (ASAR) image was acquired on 16 May 2005 in Wide Swath Mode (WSM), providing spatial resolution of 150 metres across a 400-km swath. ASAR can pierce through clouds and local darkness and is capable of differentiating between different types of ice.

The sensor has been following the movements of B-15A since the beginning of the year, gathering the highest frequency weather-independent dataset of this part of the Ross Sea.

Measuring around 115 kilometres in length with an area exceeding 2500 square kilometres, the B-15A iceberg is the world's largest free-floating object. It is the largest remaining section of the even larger B-15 iceberg that calved from the Ross Ice Shelf in March 2000 before breaking up into smaller sections.

Since then its B-15A section has drifted into McMurdo Sound, where its presence blocked ocean currents and led to a build-up of sea ice that decimated local penguin colonies, deprived of open waters for feeding. During the spring of this year prevailing currents took B-15A slowly past the Drygalski ice tongue. A full-fledged collision failed to take place, but a glancing blow broke the end off Drygalski in mid-April.

The stretch of Victoria Land coast parallel to B-15A's current position is unusually rich in wildlife, n
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Contact: Mariangela D'Acunto
mariangela.dacunto@esa.int
39-694-180-856
European Space Agency
17-May-2005