ESA satellite captures iceberg breakup

European Space AgencyParis, March 15 : A huge fissure was spotted running south to north through a massive iceberg located just east of the South Georgia Island in the southern Atlantic Ocean by ESA’s (European Space Agency) Envisat (Environmental Satellite).

The iceberg, called A53A, was spotted by scientists while studying satellite images collected from Envisat’s Advanced Synthetic Aperture Radar (ASAR) instrument using the Polar View monitoring programme.

ASAR is able to produce high-quality images of icebergs and ice sheets and is capable of differentiating between different types of ice because it is able to see through clouds and local darkness – conditions often found in polar areas.

The radar image indicated the iceberg was unstable and likely to split. Just days afterwards, on March 4, Envisat's Medium Resolution Imaging Spectrometer (MERIS) sensor captured the break.

Both icebergs are estimated to measure around 30 km in length. As a reference, South Georgia Island is approximately 180-km long.

Several different processes can cause an iceberg to form, or ‘calve’, including deterioration from high temperatures or the sun's radiation, action from winds and waves or a collision with another iceberg.

The break up of A53A, which calved off the Larsen Ice Shelf in late April 2005, occurred in relatively warm waters, making it highly likely that numerous smaller icebergs and ice islands will calve off the two icebergs. (ANI)