Professor Bentley's research interests have lain primarily in geophysical studies of the Antarctic ice sheet and the crust beneath, using both surface-based and satellite techniques. One particular focus has been on the ice sheet of West Antarctica, much of which lies on a bed far below sea level. Knowledge of ice thickness, ice properties, and basal conditions, particularly on the fast-moving ice streams, are needed to understand the past and present dynamics of the ice sheet. His main current activity is as Principal Investigator for Ice Coring and Drilling Services, a unit of the Space Science and Engineering Center that is charged with providing ice cores and boreholes for NSF-supported projects in Antarctica, Greenland, and elsewhere.For his extensive contributions to Antarctic glaciological research he was awarded the Seligman Crystal of the International Glaciological Society in 1990.