Ice sheets are found only in Greenland and Antarctica. They are huge continental masses of glacial ice and snow that cover areas over 50,000 square kilometres.
The Antarctic ice sheet is over 4200 meters thick in some areas, the result of snow building up over at least 750,000 years. It covers nearly all of the antarctic land, with the exception of the tops of the Transantarctic Mountains, which protrude above the ice. It's the largest single mass of ice on Earth, covering an area of almost 14 million km2 and containing 30 million km3 of ice. It is estimated that 90 per cent of the fresh water on the Earth's surface is frozen in this one ice sheet and,if it melted, global sea levels would rise by roughly 70m.
Photo of a section of ice sheet showing one of the few mountain tops that protrude above the ice
A satellite image from NASA showing the Antarctic ice sheet.