View into ice core borehole (IMAGE) University of Arizona Caption View looking down an ice coring borehole atop the Greenland Ice Sheet. Most of the core samples studied came from depths as deep as 300 – 1,000 feet below the ice surface. Credit Sarah Das/Woods Hole Oceanographic Institution Usage Restrictions This visual may only be used for the purpose of posting and/or reporting of this news release. Credit information must be provided as indicated. 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.