Science Source

Massive subsurface ice formed by refreezing of ice-shelf melt ponds

States that surface melt ponds form intermittently on several Antarctic ice shelves
States that, although implicated in ice-shelf break up, the consequences of such ponding for ice formation and ice-shelf structure have not been evaluated
Reports the discovery of a massive subsurface ice layer located in an area of intense melting and intermittent ponding on Larsen C Ice Shelf, Antarctica
Combines borehole optical televiewer logging and radar measurements with remote sensing and firn modelling to investigate the layer, found to be ∼10 °C warmer and ∼170 kg m−3 denser than anticipated in the absence of ponding and formerly used in models of ice-shelf fracture and flow
Concludes that surface ponding and ice layers such as the one reported are likely to form on a wider range of Antarctic ice shelves in response to climatic warming in forthcoming decades