Runaway loss of Antartica ice may last for centuries

Wellington: The runaway loss of ice from Antarctica as a result of global climate change could last for centuries, said a study on Friday.

The Victoria University-led researchers studied rocks at different elevations beside the East Antarctic Ice Sheet (EAIS) and found that a period of rapid glacier thinning occurred in the recent geological past and persisted for several centuries, Xinhua reported.

Parts of the Antarctic ice sheet were at risk of "marine ice sheet instability", where an initial retreat of ice margins into deepening valleys could lead to continued, unstable ice loss.

Lead researcher Richard Jones said the processes leading to instability could 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," Jones said in a statement.

"It might only require a small amount of climate variation to initiate runaway ice loss, and it could continue for centuries to millennia."

The process had been suggested for many years, but the study presented the first directly recorded evidence that it had taken place in the past, providing new insight into the future behaviour of rapidly changing parts of Antarctica.