Antarctic retreat

an international study has found a large number of glaciers in the Antarctic peninsular region -- a small part of the icy continent -- are retreating rapidly of late. A team of scientists from the British Antarctic Survey (bas) and the us Geological Survey (usgs) analysed 244 glaciers on the peninsula and found 87 per cent of them are becoming smaller.

"Fifty years ago, most of the glaciers we looked at were slowly growing in length but since then this pattern has reversed. In the last 5 years, the majority were actually shrinking rapidly," said Alison Cook of bas, the lead author of the study that appeared in Science (April 21, Vol 308, No 5721).

The retreat began at the northern, warmer tip of the Antarctic peninsula and moved southwards as atmospheric temperatures rose. This region has shown dramatic and localised warming -- around 2 c in the last 50 years -- which is the single most important factor causing the changes.

A complete melting of the glaciers on the Antarctic peninsular region can cause the sea level to rise about 50 centimetre, leading to the flooding of several small island nations. For the study, the scientists used 2,000 aerial photographs from the 1940s and over 100 satellite images from 1960 onwards.