Speculation over the existence of a "southern land" was not confirmed until the early 1820s when British and American commercial operators and British and Russian national expeditions began exploring the Antarctic Peninsula region and other areas south of the Antarctic Circle. Not until 1840 was it established that Antarctica was indeed a continent and not just a group of islands. Several exploration "firsts" were achieved in the early 20th century. Following World War II, there was an upsurge in scientific research on the continent. A number of countries have set up year-round research stations on Antarctica. Seven have made territorial claims, but not all countries recognize these claims. In order to form a legal framework for the activities of nations on the continent, an Antarctic Treaty was negotiated that neither denies nor gives recognition to existing territorial claims; signed in 1959, it entered into force in 1961.
There are no indigenous inhabitants, but there are both permanent and summer-only staffed research stations.
Note: 28 nations, all signatory to the Antarctic Treaty, operate through their National Antarctic Program a number of seasonal-only (summer) and year-round research stations on the continent and its nearby islands south of 60 degrees south latitude (the region covered by the Antarctic Treaty); these stations' population of persons doing and supporting science or engaged in the management and protection of the Antarctic region varies from approximately 4,000 in summer to 1,000 in winter; in addition, approximately 1,000 personnel, including ship's crew and scientists doing onboard research, are present in the waters of the treaty region; peak summer (December-February) population - 4,219 total; Argentina 667, Australia 200, Brazil 40, Bulgaria 15, Chile 237, China 70, Czech Republic 20, Ecuador 26, Finland 20, France 100, France and Italy jointly 45, Germany 90, India 65, Italy 90, Japan 125, South Korea 70, NZ 85, Norway 44, Peru 28, Poland 40, Romania 3, Russia 429, South Africa 80, Spain 28, Sweden 20, Ukraine 24, UK 205, US 1,293, Uruguay 60 (2007-2008); winter (June-August) station population - 1,088 total; Argentina 176, Australia 62, Brazil 12, Chile 96, China 29, France 26, France and Italy jointly 13, Germany 9, India 25, Italy 2, Japan 40, South Korea 18, NZ 10, Norway 7, Poland 12, Russia 148, South Africa 10, Ukraine 12, UK 37, US 337, Uruguay 9 (2008); research stations operated within the Antarctic Treaty area (south of 60 degrees south latitude) by National Antarctic Programs: year-round stations - 38 total; Argentina 6, Australia 3, Brazil 1, Chile 4, China 2, France 1, France and Italy jointly 1, Germany 1, India 1, Japan 1, South Korea 1, NZ 1, Norway 1, Poland 1, Russia 5, South Africa 1, Ukraine 1, UK 2, US 3, Uruguay 1 (2008); a range of seasonal-only (summer) stations, camps, and refuges - Argentina, Australia, Bulgaria, Brazil, Chile, China, Czech Republic, Ecuador, Finland, France, Germany, India, Italy, Japan, South Korea, New Zealand, Norway, Peru, Poland, Romania, Russia, Spain, Sweden, Ukraine, UK, US, and Uruguay (2007-2008); in addition, during the austral summer some nations have numerous occupied locations such as tent camps, summer-long temporary facilities, and mobile traverses in support of research (March 2008 est.)