Rate of ice melt in Antarctic 10 times faster than 600 years ago: study
15 Apr 2013
The rate of melting of ice in the Antarctic is 10 times faster today than it was 600 years ago, with the most rapid melting happening over the last 50 years, according to a report in today's Nature Geoscience journal.
Researchers from the Australian National University and the British Antarctic Survey also discovered the ice melt was at its peak level in 1,000 years.
According to lead researcher Nerilie Abram, it was definitely evidence that the climate and the environment were changing in that part of Antarctica.
The teams drilled a 364-metre long ice core from James Ross Island in the north of the continent to measure past temperatures in the area.
They found that while the temperatures had gradually increased by 1.6 degrees Celsius (2.9 degrees Fahrenheit) over 600 years, the rate of ice melting had been most intense over the past 50 years.
According to experts, stronger ice melts were likely to be responsible for faster glacier ice loss as also some of the dramatic collapses from the Antarctic ice shelf over the past 50 years.
The most highly detailed map yet of Antarctica's landmass, by the British Antarctic Survey has revealed a landscape of mountain ranges and plains cut by gorges and valleys much deeper than previously seen.
However, according to a report by another group of scientists in the same issue, an analysis of the West Antarctic Ice Sheet stretching back 2000 years indicated "rapid ice loss may not be all that unusual" in that area of the continent.
According to Abrams, warming in the Antarctic Peninsula could not be extrapolated to the whole southern continent.
Abram's view finds support in the second study published in Nature Geoscience led by professor Eric Steig at the University of Washington.
His team, which included Dr Ailie Gallant, from Monash University, analysed a new ice core from the West Antarctic Ice Sheet Divide that went back 2000 years, as also several ice cores dating back 200 years.
According to Gallant, their work focused on the isotope, oxygen 18; higher levels of oxygen 18 indicated higher air temperatures.
She said while they discovered large spikes in temperatures during the 1990s, there were several decades that exhibited similar climate patterns in the past 200 years.
She added when they looked over 2000 years, there were a few other blips in about 1 per cent of the record.
What it revealed was that while what was seen in the 1990s was very unusual it was not necessarily unprecedented, she added.
