Internal structure of the ice sheet between Kohnen station and Dome Fuji, Antarctica, revealed by airborne radio-echo sounding

Abstract

This study aims to demonstrate that deep ice cores can be synchronized using internal horizons in the ice between the drill sites revealed by airborne radio-echo sounding (RES) over a distance of >1000 km, despite significant variations in glaciological parameters, such as accumulation rate between the sites. In 2002/03 a profile between the Kohnen station and Dome Fuji deep ice-core drill sites, Antarctica, was completed using airborne RES. The survey reveals several continuous internal horizons in the RES section over a length of 1217 km. The layers allow direct comparison of the deep ice cores drilled at the two stations. In particular, the counterpart of a visible layer observed in the Kohnen station (EDML) ice core at 1054m depth has been identified in the Dome Fuji ice core at 575m depth using internal RES horizons. Thus the two ice cores can be synchronized, i.e. the ice at 1560m depth (at the bottom of the 2003 EDML drilling) is 49 ka old according to the Dome Fuji age/depth scale, using the traced internal layers presented in this study.