Kelsey Sanborn, University of Sydney (IMAGE) University of Sydney Caption Kelsey Sanborn, lead author, from the School of Geosciences at the University of Sydney Credit University of Sydney Usage Restrictions For this story only 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.