Antarctica

Antarctica is Earth's southernmost and least-populated continent.

It sits almost entirely south of the Antarctic Circle. The Southern Ocean surrounds the entire landmass. Antarctica is the fifth-largest continent on our planet. It covers an area of 14,200,000 square kilometers. This makes it about 40% larger than Europe. The continent also contains the geographic South Pole.

Most of the continent is covered by the Antarctic ice sheet. This massive layer of ice has an average thickness of 1.9 kilometers. This ice sheet is a vital part of Earth's water system. It holds about 70% of the world's freshwater reserves. If this ice were to melt, global sea levels would rise by almost 60 metres. Antarctica is also classified as a polar desert. It is the coldest, driest, and windiest continent. The lowest temperature ever measured there was −89.2 °C.

The geography of the continent is divided into two main regions. The Transantarctic Mountains separate West Antarctica from East Antarctica.

East Antarctica is largely covered by the East Antarctic Ice Sheet. The highest peak on the continent is the Vinson Massif. It reaches an elevation of 4,892 metres. Another notable feature is Mount Erebus on Ross Island. It is the world's southernmost active volcano. It erupts approximately 10 times every day. There are also many volcanoes hidden beneath the ice.

Antarctica contains several unique water features. Some lakes exist at the base of the ice sheet. These are found in the McMurdo Dry Valleys or in various oases. Lake Vostok is a massive subglacial lake. It is the largest subglacial lake in the world. Scientists believe its water is replaced every 13,000 years. This happens through a cycle of slow melting and freezing. The continent also has various ice shelves. These are large floating platforms of ice. About 44% of the coastline consists of these ice shelves.

Human exploration of Antarctica began in earnest during the 19th century. Russian explorers Fabian Gottlieb von Bellingshausen and Mikhail Lazarev first saw the ice shelves in 1820. Many other nations, including France, America, and Britain, sent expeditions later. A Norwegian team made the first confirmed landing in 1895. In 1909, British explorers reached the magnetic South Pole. Roald Amundsen, a Norwegian explorer, reached the geographic South Pole in 1911. These explorers faced extreme conditions to map the frozen territory.

Today, Antarctica is governed by the Antarctic Treaty System of 1959. About 30 countries are parties to this treaty. The treaty prohibits military activity and mining. It also bans nuclear explosions and nuclear waste disposal. Instead, people focus on research, tourism, and fishing. During the summer, about 5,000 people live at research stations. This number drops to around 1,000 during the winter. Despite its distance, human activities like pollution and climate change affect the continent.

The history of Antarctica is tied to the supercontinent Gondwana. Antarctica was part of this landmass until it began breaking apart 183 million years ago. In the past, Antarctica had a much warmer climate. During the Paleozoic era, it was covered in forests. Plants like the extinct Glossopteris grew in waterlogged soils. During the Mesozoic era, dinosaurs lived in Antarctica. Genera such as Cryolophosaurus and Antarctopelta have been described. As the continent drifted south, it became much colder and glaciated.