High Sierra Erosion (1 of 2) (IMAGE) University of Wyoming Caption Claire Lukens, a UW doctoral student co-author of a paper in PNAS, samples sediment from hill slopes in Inyo Creek in California. Hill slope samples were used to determine the intensity of chemical weathering across the landscape, which may help explain why the size of eroded sediment varies from place to place. Credit Marlie Malone Photo Usage Restrictions None 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.