Ancient Antarctic ice melt increased sea levels by 3+ metres – and it could happen again 

Mass melting of the West Antarctic Ice Sheet was a major cause of high sea levels during a period known as the Last Interglacial (129,000-116,000 years ago), an international team of scientists led by UNSW’s Chris Turney has found. The research was published today in Proceedings of the National Academy of Sciences (PNAS).
 
The extreme ice loss caused a multi-metre rise in global mean sea levels – and it took less than 2˚C of ocean warming for it to occur. 

Fine layers of ancient volcanic ash in the ice helped the team pinpoint when the mass melting took place. Alarmingly, the results indicated that most ice loss occurred within the first millennia, showing how sensitive the Antarctic is to higher temperatures. 

Blue ice areas are the perfect laboratory for scientists due to their unique topography – they are created by fierce, high-density katabatic winds. When these winds blow over mountains, they remove the top layer of snow and erode the exposed ice. As the ice is removed, ancient ice flows up to the surface, offering an insight into the ice sheet’s history.