Volume Loss From Antarctic Ice Shelves Is Accelerating, Finds Study
By Countercurrents.org
27 March, 2015
Countercurrents.org
Scientists have warned: The ice around the edge of Antarctica is melting faster than previously thought, potentially unlocking meters of sea-level rise in the long-term.
The new research, published in the journal Science on March 26, 2015, found for the first time that ice shelf melt is accelerating. A team of US scientists have conducted the research. Using eighteen years of continuous satellite radar altimeter observations have computed decadal-scale changes in ice-shelf thickness around the Antarctic continent.
The floating ice shelves surrounding the Antarctic Ice Sheet restrain the grounded ice-sheet flow. Thinning of an ice shelf reduces this effect, leading to an increase in ice discharge to the ocean.
Overall, average ice-shelf volume change accelerated from negligible loss at 25 ± 64 km3 per year for 1994-2003 to rapid loss of 310 ± 74 km3 per year for 2003-2012. West Antarctic losses increased by 70% in the last decade, and earlier volume gain by East Antarctic ice shelves ceased. In the Amundsen and Bellingshausen regions, some ice shelves have lost up to 18% of their thickness in less than two decades.
A Guardian report on the finding said:
The UN’s climate science body has not previously included the ice sheets of Antarctica and Greenland in its predictions for future sea level rise because scientists are not certain how fast they will slide into the ocean.
Over the past decade the loss of ice shelf volume in Antarctica increased from 25km3 to 310km3 every year.
It is unclear whether the loss of ice is directly related to man-made climate change or a cyclical change in ocean currents. But the extra sea level rise from ice sheets will exacerbate the rise caused by the expansion of oceans as the world warms.
The western coast ice shelves contributed the majority of the ice loss. The rate of loss increased by 70% in the last decade. Two shelves in this region could completely disappear within a century. Conversely, there were some areas in east Antarctica where the shelves stayed stable or grew slightly. Vaughan said the regional variations were predicted by previous studies.
.
Comments are moderated