Vol. 39, No. 132, p. 381
The penultimate paragraph in column b should read: Bamber (1987) has shown that the IRH level in two-layered glaciers on Spitsbergen is well described by the piezometric surface of Röthlisberger channels (Röthlisberger, 1972). The IRHs themselves, which were observed in spring before the melting season, are hypothesized to be the residues of a large-scale network of conduits which drain the surface meltwaters to one or more channels at depth. Some of these are closed off in the winter and water is trapped in cavities which remain in the ice at the melting-point temperature (Bamber, 1988).