Laboratory Analyses (IMAGE) University of Copenhagen - Niels Bohr Institute Caption From ice core measurements, scientists can calculate the amount of sea ice in the Arctic ocean in the past. Credit Credit: Ole Jakup Joensen, NBI. Usage Restrictions Credit: Ole Jakup Joensen, NBI. 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.