Channels Revealed Underneath Antarctic Ice Shelves

Ice shelves exist at the boundary between ocean and ice. They are the edges of ice sheets, massive sections of ice made of compacted snow and sitting atop continents. The ice shelf is where most of the action occurs: it’s where icebergs calve off, where friction with the underlying coastline affects ice flows, and where ocean water beneath the shelf causes melting. There are also basal channels of liquid water carved into the ice on the shelf’s underside. Hidden and inaccessible underneath giant blocks of ice, basal channels' distribution throughout the Antarctic ice shelves has remained largely unknown. But recently, researchers have used satellite imagery and correlations between ridges and depressions on the surface and the channels below to map out all of the larger basal channels of the Antarctic ice shelves. They’ve also found that these channels are conduits for warm water, and therefore critical in determining melting rates of collapsing ice shelves. Further study of these channels, their formation, and their dynamics will improve ice shelf models and help us understand the Antarctic ice sheet’s overall stability and health as the planet warms.

-Sean Faulk
Staff Writer, Signal to Noise Magazine

PhD Candidate, Earth, Planetary, and Space Sciences

Alley KE, Scambos TA, Sigrid MR, Fricker HA. Impacts of warm water on Antarctic ice shelf stability through basal channel formation. Nature Geoscience. (2016). DOI: 10.1038/ngeo2675