We have discovered a band of stones and coarse sand in the Ronne Ice Shelf, Antarctica,
some 60m above the ice shelf’s base, 40km from its seaward edge and 420km from the point where the
ice originally went afloat. A study of ice-sounding radar data from across the Ronne Ice Shelf has
revealed other areas likely to contain debris in significant quantities. It appears that basal debris at the
margins of ice streams feeding the ice shelf can be buried in the ice shelf by sea water freezing-on at the
ice-shelf base. These findings are evidence for a mechanism active in a present-day ice-sheet/shelf
system, which enables icebergs to transport large volumes of ice-rafted debris, and which also provides
a potential mechanism for the formation of ice rises near ice fronts. We anticipate that a seismics study
of debris melted from the ice shelf and deposited beneath will provide a valuable control on the history
of ice-shelf–ocean interactions.
Authors: Nicholls, K.W., Corr, H.F.J., Makinson, K., Pudsey, C.J.