In a new study led by Victoria University of Wellington, UNSW researchers have revealed the potential for runaway ice loss in Antarctica.
By studying rocks at different elevations beside the East Antarctic Ice Sheet (EAIS), the team concluded that a period of rapid glacier thinning occurred in the recent geological past, and persisted for several centuries.
Satellite observations show that parts of the Antarctic ice sheet are currently thinning in response to a warming ocean. Of particular concern is the potential for ‘marine ice sheet instability’, where an initial retreat of ice margins into deepening valleys could lead to continued, unstable ice loss.
The new research indicates the processes leading to instability can be initiated by just minor climate warming.
“The finding is very important for predicting Antarctica’s future contribution to sea level change, particularly when considering that the EAIS contains enough vulnerable ice to raise sea level by tens of metres,” said UNSW author on the study Dr Chris Fogwill.
“It might only require a small amount of climate variation to initiate runaway ice loss, and it could continue for centuries to millennia,” said Dr Fogwill, from the School of Biological, Earth And Environmental Sciences and UNSW’s Climate Change Research Centre.
While this process has been posited for many years, the study presents the first directly recorded evidence that it has taken place in the past, providing new insight into the future behaviour of rapidly changing parts of Antarctica today.
A major strength of the study was combining numerical modelling experiments that simulate glacier retreat with geological data processed in Victoria University’s world-class cosmogenic nuclide laboratory.
The laboratory studies rare isotopes produced through the interaction of cosmic radiation with minerals on the Earth’s surface, which allows for the calculation of the age of a rock surface.
“Most research has previously focused on the West Antarctic Ice Sheet, which makes these observations from East Antarctica all the more significant,” said lead author of the study Victoria Postdoctoral Research Fellow Dr Richard Jones.
The research has been published in the journal Nature Communications.