Few studies conducted by scientists during recent times have made some glaring exposures about the Antarctic ice sheet. The scientists have found that the ice sheet began melting about 5,000 years earlier than previously thought – at the end of last ice age.
According to the researchers, the melting of the ice sheet accelerated during eight distinct episodes. This has caused rapid rise in the sea level.
Lead author Michael Weber, a scientist from University of Cologne in Germany, said, “Conventional thinking is that the Antarctic ice sheet has been relatively stable since the last ice age, that it began to melt relatively late and that its decline was slow and steady until it reached its present size.”
According to Weber, the sediment record suggests a different pattern – one that is more episodic and suggests that parts of the ice sheet repeatedly became unstable during the last deglaciation.
For the study, the scientists examined two sediment cores containing iceberg-rafted debris from the Scotia Sea between Antarctica and South America.
The periods of rapid increases in the said debris indicated that the icebergs were being released by the Antarctic ice sheet.
There was a discovery of increased amounts of debris during eight separate episodes beginning as early as 20,000 years ago, and continuing until 9,000 years ago.
According to the scientists the melting of the Antarctic Ice Sheet was not thought to have began, however, until 14,000 years ago.
“During that time, the sea level on a global basis rose about 50 feet in just 350 years – or about 20 times faster than sea level rise over the last century. We do not yet know what triggered these eight episodes or pulses, but it appears that once the melting of the ice sheet began it was amplified by physical processes,” said Peter Clark, an Oregon State University paleoclimatologist.
“However, our new results suggest that the Antarctic Ice Sheet is more unstable than previously considered,” the researchers said.
The study was published in the journal Nature.
