Greenland Ice Sheet (image) Dartmouth College Caption This is the 2012 Summit firn melt layer of the Greenland ice sheet. The white layer at about 2cm depth shows the new melt layer formed from the mid-July warm temperatures. Credit Kaitlin Keegan Usage Restrictions Credit Kaitlin Keegan 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.