A National Science Foundation funded-study by the University of South Florida documents the evolution of Antarctic ice sheets, 20 million years ago
During the period known as the Early Miocene, Earth was experiencing both warm and cold climates and sea level changes. Atmospheric concentrations of carbon dioxide were similar to what is expected to be the norm in 2100, if greenhouse gas concentrations continue at their current rate.
The warm weather of the Early Miocene period resulted in sea level rising by up to 60 meters – the equivalent of melting all the ice currently on the Antarctic continent.
Conducted as part of International Ocean Discovery Program( IODP)Expedition 374 to the Ross Sea in Antarctica, the IODP Expedition 374 recovered some 1.5 kilometers (nearly 1 mile) of mud from the ocean floor, which scientists used to reconstruct Antarctica’s ice sheet evolution over the last 20 million years.
West Antarctic Sea Ice
The west Antarctic sea ice (WAIS) -the smaller and more climatically sensitive of today’s Antarctic ice sheets – existed and contributed significantly to global sea level 8 million years earlier than previously known.
Lead by researcher Jim Marschalek this research provides essential data for climate models used to predict future global sea levels as Earth warms and ice around the globe continues to melt.
“Understanding past climate conditions and the behaviour of Antarctica’s ice sheets is essential to predicting how much and how fast sea levels will rise in the future,” said researcher Amelia Shevenell.
“Understanding past climate conditions and the behaviour of Antarctica’s ice sheets is essential to predicting how much and how fast sea levels will rise in the future”
Research revealed that the young west Antarctic sea ice was highly erosive which resulted in the lowering of the land beneath the ice to below sea level putting it in more danger and therefore increasing its vulnerability to climate and ocean changes.
“What’s happening in Antarctica now and in the past may not seem important in our everyday lives. But the West Antarctic Ice Sheet is contributing to global sea level rise, and its contributions are increasing as Earth warms. If this part of Antarctica were to melt completely, global sea levels would rise about 15 feet, which would displace millions of people worldwide,” said Shevenell.
