The Slice Nobody Claimed
Seven countries carved Antarctica into wedges that meet at the South Pole. Three of them stacked their claims on the same peninsula. And one wedge, facing the empty South Pacific, was left to no one at all.
The largest piece of land on Earth that no country claims — a little bigger than Mongolia, roughly 11% of Antarctica (derived), lying in the sector between 150°W and 90°W.
Seven slices, very unequal
Each claim is a wedge from the coast to the Pole. Australia's alone covers about 42% of the continent; the unclaimed wedge outranks four of the claims.
Million km², as stated by each claimant (definitions differ; UK, Chile & Argentina overlap)
Seven claims in 34 years, then a freeze
From Britain's Letters Patent in 1908 to Argentina's decree in 1942, every claim landed before the Second World War ended. In 1959 the Antarctic Treaty froze them where they stood.
Going around the Pole, count the owners
Walk the 360° of longitude: most of the way, one country. Between 74°W and 53°W, three. Between 150°W and 90°W, zero.
Three on one peninsulaThe Antarctic Peninsula is the warmest, most accessible part of the continent, closest to South America. Britain (1908), Chile (1940) and Argentina (1942) all claim it; 21° of longitude, from 74°W to 53°W, is claimed by all three.
Why the gap faces the PacificMarie Byrd Land is among the most remote coasts on Earth, ringed by the Amundsen Sea's pack ice. The US explored it (and named it after Richard Byrd's wife) but never claimed it — and under the Treaty, no new claims may be made.
Frozen, not settled
Article IV of the 1959 Treaty neither recognises nor rejects any claim — and bars new ones while it is in force.
States signed the Antarctic Treaty on 1 Dec 1959 — the seven claimants plus five others, including the US and USSR.
States are now Parties to the Treaty; 29 of them hold decision-making Consultative status.
The Madrid Protocol's ban on all mineral resource activity (Art. 7) entered into force.
After this year any Consultative Party may request a review conference. The ban does not expire.
A continent of visitors
Nobody is born a citizen of Antarctica. The people living under all these flags are scientists and support staff, and they come and go with the seasons.
Read the wedges, then the gap
- Every border is a meridian. No river, ridge or coastline decides where one country stops — only lines of longitude running to the Pole.
- Darkest ink is the most contested ground. The Antarctic Peninsula carries three overlapping claims, all facing South America.
- The orange wedge is the anomaly. Between 150°W and 90°W, roughly 1.61M km² of ice-covered land belongs to no state — except Peter I Island offshore, which Norway does claim.
- The 60°S ring is the real border. Everything inside it is governed jointly by the Treaty, whatever the wedges say.
Sources & notes
- Marie Byrd Land ≈1.61M km², largest unclaimed land on Earth; extent 158°W–103°24′W. Wikipedia, “Marie Byrd Land” (compiled from USGS/SCAR gazetteers), accessed 2026.
- Antarctica ≈14.2M km²; population ≈4,400 summer / ≈1,100 winter. CIA World Factbook, “Antarctica” (2024–25 edition).
- Australian Antarctic Territory ≈5.9M km², ~42% of Antarctica; claim 1933. Australian Antarctic Division (Australian Government), 2024.
- Queen Maud Land ≈2.7M km²; claim 14 Jan 1939. Norwegian Polar Institute / Wikipedia “Queen Maud Land”, accessed 2026.
- British Antarctic Territory 1,709,400 km²; Letters Patent 1908. UK Government, British Antarctic Territory; Wikipedia, accessed 2026.
- Chilean Antarctic Territory 1,250,257 km²; Decree 1747, 1940. Government of Chile; Wikipedia “Chilean Antarctic Territory”, accessed 2026.
- Argentine Antarctica 965,597 km² land (1,461,597 km² incl. ice/sea); first formal claim 1942, 25°W–74°W. INDEC (Argentina) via Wikipedia “Argentine Antarctica”, accessed 2026.
- Ross Dependency ≈450,000 km² land (1923); Adélie Land ≈432,000 km² (1924). NZ Government / TAAF; Wikipedia, accessed 2026.
- Antarctic Treaty signed 1 Dec 1959 by 12 states; 58 Parties, 29 Consultative; Article IV freezes claims. Secretariat of the Antarctic Treaty, 2025.
- Madrid Protocol signed 4 Oct 1991, in force 14 Jan 1998; Art. 7 bans mineral resource activity; review conference may be requested after 2048. Protocol on Environmental Protection to the Antarctic Treaty, Arts. 7 & 25 (ATS).
Map is schematic: a hand-simplified south-polar azimuthal sketch, not survey-accurate. Claim sectors are drawn at their stated meridians; Norway has never formally defined the lateral or southern limits of Queen Maud Land, shown here as conventionally mapped (20°W–44°38′E). Claim areas come from each claimant and use different definitions (land only vs. land + ice shelves), and the UK, Chilean and Argentine claims overlap, so they do not sum to 14.2M km². “≈11% of the continent” is derived (1.61 ÷ 14.2), not an official figure.