- Astrolabe Subglacial Basin
- Antarctica (N/A)
The thickest ice in the world forms part of the Antarctic Ice Sheet where it sits over a region known as the Astrolabe Subglacial Basin to the south of the Adélie Coast. Here, the ice sheet has been measured to be 4,897 metres (16,066 feet) thick. The basin is named after Astrolabe, the flagship of the French Antarctic Expedition (1837–40).
Ice thickness is often measured using ice-penetrating radar, and many areas of Antarctica remain unsurveyed, which means that thicker ice could exist but has yet to be measured.
Previously, the greatest recorded thickness of ice was 4,780 metres (15,682 feet), as measured by radio echo soundings from a US Antarctic research aircraft at 69°56'17 in Wilkes Land, eastern Antarctica.
The research that confirmed this as the thickest ice recorded to date was published in the journal The Cryosphere on 28 February 2013.