Environmental Law

Antarctic glacier melt maybe 'not due to climate change' ? The Register

By STEPHEN HOLZER

British and international boffins, having probed an Antarctic glacier which is thought to be a major cause of rising sea levels worldwide, report that increased polar ice melting may not be driven by climate change.

***

Many scientists have theorised that the PIG's accelerating flow is due to global warming. However, recent research - including surveys beneath the bottom of the floating, projecting ice sheet by Blighty's Autosub robot probe - indicate that this may not be the case. (The Autosub, famously, was powered by some 5,000 ordinary alkaline D-cell batteries on each trip beneath the ice, getting through some four tonnes of them during the research.)

It appears from the Autosub's under-ice surveys that the PIG's ice flow formerly ground its way out to sea across the top of a previously unknown rocky underwater ridge, which tended to hold it back.

Many years ago, however, before the area was surveyed in much detail, the glacier's floating outflow sheet separated from the ridge top which it had been grinding away at for millennia and so picked up speed. This also allowed relatively warm sea water to get up under the sheet and so increase melting and ease of movement.

?The discovery of the ridge has raised new questions about whether the current loss of ice from Pine Island Glacier is caused by recent climate change or is a continuation of a longer-term process that began when the glacier disconnected from the ridge," says Dr Adrian Jenkins of the British Antarctic Survey.

via www.theregister.co.uk

Full post as published by Environmental Legal Blogs on June 21, 2010 (boomark / email).