Einstein Science Reporting for Kids
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21-Jan-2005

Contact: Karina De Castris
Karina.De.Castris@esa.int
European Space Agency

Antarctic giant on the loose



ASAR image of iceberg
Click here for a high resolution photograph.

At the bottom of the world, an enormous, bottle-shaped iceberg has been threatening to demolish everything in its path. And ESA’s Envisat spacecraft has been watching every move.

Every summer, huge chunks of floating ice break away from the cold southern continent of Antarctica. However, in March 2000, something special happened when a block the size of Jamaica broke away from the Ross Ice Shelf. Over the next few years, the world's largest known iceberg split into many pieces. The biggest slab, known as B-15A, eventually found its way to McMurdo Sound, where it blocked ocean currents and led to a build-up of sea ice.

This caused a problem for supply ships trying to reach scientific bases. It also meant that the extra sea ice cut off penguins from their normal feeding grounds.

In recent weeks, B-15A has been steadily steaming towards a long tongue of ice that sticks out into the sea. By early January, the gap had narrowed to less than 4 km.

Scientists expected to see a collision of giants as B-15A crashed into the floating Drygalski Ice Tongue. Instead, the iceberg appeared to stop in its tracks and even reverse course slightly.

It seems that B-15A may be grounded on the bottom of the shallow sea. Will the influence of wind, tides and bottom melting eventually allow it to float free?

Whatever happens, Envisat's radar vision will 'see' through the Antarctic clouds to give researchers a ringside seat.

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Click here to view animated flyover.