Conductivity and oxygen isotope measured on ice core FRI09C90_13 (B13) from the Filchner-Ronne ice shelf, Antarctica

• Main Authors: Oerter, Hans, Kipfstuhl, Sepp, Determann, Jürgen, Miller, Heinz, Wagenbach, Dietmar, Minikin, Andreas, Graf, Wolfgang
• Format: Dataset
• Language: English
• Published: PANGAEA 1992
• Subjects: AWI_Glac; B13 BC90; Conductivity; electrolytic; Depth; bottom/max; ice/snow; top/min; Electrical conductivity method; ECM (Hammer; 1980); Filchner Ronne Ice Shelf; Filchner-Ronne-Ice-Shelf-Project; FRI09C90_13; FRISP 1992; Glaciology @ AWI; ICEDRILL; Ice drill; Mass spectrometer Finnigan Delta-S; Sampling/drilling ice; δ18O; water; Antarctic; Ronne Ice Shelf; West Antarctic Ice Sheet; Antarc*; Antarctica; Filchner-Ronne Ice Shelf; ice core; Ice Sheet; Ice Shelf; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.548746; https://doi.org/10.1594/PANGAEA.548746

The Filchner-Ronne ice shelf, which drains most of the marine-based portions of the West Antarctic ice sheet, is the largest ice shelf on Earth by volume. The origin and properties of the ice that constitutes this shelf are poorly understood, because a strong reflecting interface within the ice and the diffuse nature of the ice?ocean interface make seismic and radio echo sounding data difficult to interpret. Ice in the upper part of the shelf is of meteoric origin, but it has been proposed that a basal layer of saline ice accumulates from below. Here we present the results of an analysis of the physical and chemical characteristics of an ice core drilled almost to the bottom of the Ronne ice shelf. We observe a change in ice properties at about 150 m depth, which we ascribe to a change from meteoric ice to basal marine ice. The basal ice is very different from sea ice formed at the ocean surface and we propose a formation mechanism in which ice platelets in the water column accrete to the bottom of the ice shelf.