Investigation of the 18O Content of a 100 m Ice Core From the Ronne Ice Shelf, Antarctica

A 100 m ice core from the Ronne Ice Shelf, drilled during the 1983-84 field season, was dated by isotopic stratigraphy, using the well-known seasonal variation in the 18 O content in firn and ice; the layers at a depth of 89 m are probably 400 years old. Layer thicknesses deduced from the 18 O profile indicate short-term variations of the snow-accumulation rate over the last 400 years. The area of deposition of the material recovered with the core is estimated by a two-dimensional flow model and by the 18 O content of the core, which decreases from –27.5‰ in the upper part of the core to –32.0‰ at 89 m depth.