Ice shelf

From Climate State Wiki
Close-up of Ross Ice Shelf

An ice shelf is a large floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland, Northern Canada, and the Russian Arctic. The boundary between the floating ice shelf and the anchor ice (resting on bedrock) that feeds it is the grounding line. The thickness of ice shelves can range from about 100 m (330 ft) to 1,000 m (3,300 ft).

In contrast, sea ice is formed on water, is much thinner (typically less than 3 m (9.8 ft)), and forms throughout the Arctic Ocean. It is also found in the Southern Ocean around the continent of Antarctica.

The movement of ice shelves is principally driven by gravity-induced pressure from the grounded ice.[1] That flow continually moves ice from the grounding line to the seaward front of the shelf. In steady state, about half of Antarctica's ice shelf mass is lost to basal melt and half is lost to calving, but the relative importance of each process varies significantly between ice shelves.[2][3] In recent decades, Antarctica's ice shelves have been out of balance, as they have lost more mass to basal melt and calving than has been replenished by the influx of new ice and snow.[4]


  1. Greve, R.; Blatter, H. (2009) Dynamics of Ice Sheets and Glaciers Springer
  2. Rignot, E.; Jacobs, S.; Mouginot, J.; Scheuchl, B. (2013) Ice-shelf melting around Antarctica UC Irvine
  3. Depoorter, M., Bamber, J., Griggs, J. et al. (2013) Calving fluxes and basal melt rates of Antarctic ice shelves Nature
  4. Greene, C.A., Gardner, A.S., Schlegel, NJ. et al. (2022) Antarctic calving loss rivals ice-shelf thinning Nature