Largest glacier in East Antarctica is melting due to warm ocean water
by Sarah Griffiths for Mailonline on 17 Mar 2015
Australian scientists say that waters around Totten Glacier (pictured) which contains ice equivalent to a 20-foot (six metre) rise in global sea levels, are warmer than expected and are probably melting the ice form below - East Antarctica's Totten glacier melting Daily Mail UK Associated Newspapers Ltd
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The largest glacier in East Antarctica is melting due to warm ocean water, according to Australian scientists.
Until recently, the 74-mile-long (120km) Totten Glacier was thought to be surrounded by cold waters and therefore very stable and unlikely to shrink.
But now experts say that waters around the glacier are warmer than expected and are probably melting the ice from below.
Scientists believe the glacier contains enough water to cause a 20-foot (six-meter) rise in global sea levels if it melted entirely.
'We knew that the glacier was thinning from the satellite data, and we didn't know why,’ Steve Rintoul, the voyage's chief scientist told AFP.
The expedition found that waters around the glacier, which is 18 miles (30km) wide, were 1.5 °C warmer than other areas visited on the same trip during the southern hemisphere summer.
‘We made it to the front of the glacier and we measured temperatures that were warm enough to drive significant melt,’ Dr Rintoul said.
‘And so the fact that warm water can reach this glacier is a sign that East Antarctica is potentially more vulnerable to changes in the ocean driven by climate change than we used to think.’
Previous expeditions had been unable to get close to the glacier due to heavy ice, but Dr Rintoul said the weather had held for the Aurora Australis icebreaker and a team of scientists and technicians from the Australian Antarctic Division and other bodies to investigate.
Dr Rintoul stressed that the glacier is not about to melt entirely overnight and cause a 20 ft rise in sea levels, but that research will help scientists predict how changes in ocean temperatures will impact on ice sheets.
‘This study is a step towards better understanding of exactly which parts of the ice sheets are vulnerable to ocean warming and that is the sort of information that we can then use to improve our predictions of future sea level rises,’ he said.
‘East Antarctica is not as protected from change as we use to think,’ he said.
The melt rate of glaciers in the fastest-melting part of Antarctica has tripled over the past decade, analysis of the past 21 years showed in a report published last month.
West Antarctica at triple the rate it was a decade ago
The Amundsen Sea has long been thought to be the weakest ice sheet in the West Antarctic.
Last month a US study suggested the barren region is hemorrhaging ice at a rate triple that of a decade ago.
Researchers believe that the melting of glaciers in West Antarctica may be irreversible.
The findings of the 21-year study by Nasa and the University of California, Irvine claim to provide the most accurate estimates yet of just how fast glaciers are melting in the Amundsen Sea Embayment.
Scientists found the rate by taking radar, laser and satellite measurements of the glaciers' mass between 1992 and 2013.
They found they lost an average 83 gigatons per year (91.5 billion U.S. tons), or the equivalent of losing the water weight of Mount Everest every two years.
'The mass loss of these glaciers is increasing at an amazing rate,' said scientist Isabella Velicogna, jointly of the University of California, Irvine and Nasa's Jet Propulsion Laboratory.
'Previous studies had suggested that this region is starting to change very dramatically since the 1990s, and we wanted to see how all the different techniques compared,' added lead author Tyler Utterley of UCI.
Nasa animation of ice melting and glaciers separating - video
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