Air bubbles in ice core (IMAGE) University of Cambridge Caption Evidence contained within an ice core shows that in one location the West Antarctic ice sheet thinned by 450 metres — that’s more than the height of the Empire State Building — in just under 200 years. Credit University of Cambridge/British Antarctic Survey Usage Restrictions Credit University of Cambridge/British Antarctic Survey License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.