On the Underside Scarring of Floating Ice Sheets

Abstract

Detailed analysis of radar images, obtained using a synthetic aperture radar technique, from the bottom surface of a floating ice sheet suggests the presence of linear, groove-type scarring. The dominant physical parameters, such as the orientation, depth, and periodicity of the underside scarring, are derived. Although these results relate to the bottom roughness of Bach Ice Shelf (Alexander Island), Antarctica, close to its line of grounding, they are comparable to those of the underside of Ross Ice Shelf. It therefore seems probable that the roughness parameters, measured on Ross Ice Shelf using standard radio-echo techniques, relate to linear grooves which were introduced in the region of ice grounding. Such scarring runs along the direction of ice flow and is thought to be a drawn-out imprint of the bedrock surface where the ice was last grounded.