Ice Melt in Antarctica is at the Highest in 1,000 Years, Researchers Say
Antarctica's summer ice melt is at its highest level in 1,000 years, according to Australian and British researchers.
Researchers from the Australian National University and the British Antarctic Survey found the summer ice melt has been 10 times more intense over the past 50 years when compared to 600 years ago. The findings were published this week in the journal Nature Geoscience.
The research shows the importance of an international effort to understand the causes of environmental change in Antarctica, as well as the impact of global warming on Antarctica's ice shelves and glaciers, according to Red Orbit.
In 2008 a UK-French science team drilled a 364-metre long ice core near the northern tip of the Antarctic Peninsula to measure past temperatures in the area. The drilling provided an unexpected insight into ice melt in the region by uncovering visible layers in the ice core which indicated periods when summer snow on the ice cap thawed and then refroze. Scientists measured the thickness of these melt layers in order to examine how the history of melting compared with changes in temperature at the ice core site over the last 1000-years.
"Summer melting at the ice core site today is now at a level that is higher than at any other time over the last 1000 years. And whilst temperatures at this site increased gradually in phases over many hundreds of years, most of the intensification of melting has happened since the mid-20th century," said lead author Dr Nerilie Abram of The Australian National University and British Antarctic Survey.
"What that means is that the Antarctic Peninsula has warmed to a level where even small increases in temperature can now lead to a big increase in summer ice melt."
"Having a record of previous melt intensity for the Peninsula is particularly important because of the glacier retreat and ice shelf loss we are now seeing in the area. Summer ice melt is a key process that is thought to have weakened ice shelves along the Antarctic Peninsula leading to a succession of dramatic collapses, as well as speeding up glacier ice loss across the region over the last 50 years," said Dr Robert Mulvaney, from the British Antarctic Survey.
The new ice core record shows that even small changes in temperature can result in large increases in the amount of melting, Abram says.