The Ice Sheet Grounding Line (IMAGE) Northern Illinois University Caption The Ice Sheet Grounding Line at the end of the last Ice Age; about 10,000 years ago; and today. Credit Jonathan Kingslake of Columbia University's Lamont-Doherty Earth Observatory Usage Restrictions Credit Jonathan Kingslake of Columbia University's Lamont-Doherty Earth Observatory. License Licensed 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.