An ice shelf is large piece of ice floe (floating ice) attached to the coast and formed by the advance of a glacier into the sea. The largest ice shelf is the Ross ice shelf (or barrier) in Antarctica, of which the surface area is around 487,000 km2 (compared with the 676,600 km2 of Texas or 209331 km2 of Great Britain).
On the Ross ice shelf, in the Bay of Whales. This is where Roald Amundsen left on his expedition to the South Pole in October 1911. © Michael Van Woert/NOAA / Flickr CC by-nc-sa 2.0