Age of Crary Ice Rise, Antarctica, Determined from Temperature-Depth Profiles

Abstract

Temperature-depth measurements from two sites on Crary Ice Rise, Antarctica are analyzed to deduce the time the ice first grounded at each location. At the thicker site (480 m), the best estimate of the time since grounding is 1100 years. At the shallower site (369 m) the grounding is more recent, 580 years ago, and there is evidence that basal cooling was delayed for 450 years while water at the base was freezing. This analysis leads to the conclusion that Crary Ice Rise was formed by at least two separate grounding events and is not a remnant of a more extensive grounded ice sheet which occupied the present position of the Ross Ice Shelf.