The South Pole is the southernmost point on Earth. It is the precise point of the southern intersection of Earth's axis and Earth's surface.

From the South Pole, all directions are north. Its latitude is 90 degrees south, and all lines of longitude meet there (as well as at the North Pole).

The South Pole is located on Antarctica, one of Earth's seven continents. Although land at the South Pole is only about a hundred meters above sea level, the ice sheet above it is roughly 2,700-meters (9,000-feet) thick. This elevation makes the South Pole much colder than the North Pole, which sits in the middle of the Arctic Ocean. In fact, the warmest temperature ever recorded at the South Pole was a freezing -12.3 degrees Celsius (9.9 degrees Fahrenheit).

The South Pole is close to the coldest place on Earth. The coldest temperature recorded at the South Pole, -82.8 degrees Celsius (-117.0 degrees Fahrenheit), is still warmer than the coldest temperature ever recorded, -89.2 degrees Celsius (-128.6 degrees Fahrenheit). That temperature was recorded at the Russian Vostok Research Station, about 1,300 kilometers (808 miles) away.

Because Earth rotates on a tilted axis as it revolves around the sun, sunlight is experienced in extremes at the poles. In fact, the South Pole experiences only one sunrise (at the September equinox) and one sunset (at the March equinox) every year. From the South Pole, the sun is always above the horizon in the summer and below the horizon in the winter. This means the region experiences up to 24 hours of sunlight in the summer and 24 hours of darkness in the winter.

Due to plate tectonics, the exact location of the South Pole is constantly moving. Plate tectonics is the process of large slabs of Earth's crust moving slowly around the planet, bumping into and pulling apart from one another.

Over billions of years, Earth's continents have shifted together and drifted apart. Millions of years ago, land that today is the east coast of South America was at the South Pole. Today, the ice sheet above the South Pole drifts about 10 meters (33 feet) every year.

Amundsen–Scott South Pole Station

Compared to the North Pole, the South Pole is relatively easy to travel to and study. The North Pole is in the middle of the Arctic Ocean, while the South Pole is on a stable piece of land.

The United States has had scientists working at Amundsen–Scott South Pole Station since 1956. Between 50 and 200 scientists and support staff live at the this research station at any given time. The station itself does not sit on the ground or ice sheet. It is able to adjust its elevation, to prevent it from being buried in snow, which accumulates at a rate of about 20 centimeters (eight inches) every year, and does not melt.

In the winter, the Amundsen–Scott South Pole Station is completely self-sufficient. The dark sky, freezing temperatures, and gale-force winds prevent most supplies from being flown or trekked in. All food, medical supplies, and other material must be secured before the long Antarctic winter. The station's energy is provided by three enormous generators that run on jet fuel.

In winter, stores of food are supplemented by the Amundsen–Scott South Pole Station's greenhouse. Vegetables in the greenhouse are grown with hydroponics, in a nutrient solution instead of soil.

Some of the earliest discoveries made at South Pole research stations helped support the theory of continental drift, the idea that continents drift apart and shift together. Rock samples collected near the South Pole and throughout Antarctica match samples dated to the same time period collected at tropical latitudes. Geologists conclude that the samples formed at the same time and the same place, and were torn apart over millions of years, as the planet split into different continents.

Today, the Amundsen–Scott South Pole Station is host to a wide variety of research. The relatively undisturbed ice sheet maintains a pristine record of snowfalls, air quality, and weather patterns. Ice cores provide data for glaciologists, climatologists, and meteorologists, as well as scientists tracking patterns in climate change.

The South Pole has low temperatures and humidity and high elevation, making it an outstanding place to study astronomy and astrophysics. The South Pole Telescope studies low-frequency radiation, such as microwaves and radio waves. The South Pole Telescope is one of the instruments designed measure the cosmic microwave background (CMB)–faint, diffuse radiation left over from the Big Bang.

Astrophysicists also search for tiny particles called neutrinos at the South Pole. Neutrinos interact very, very weakly with all other matter. Neutrino detectors therefore must be very large to detect a measurable number of the particles. The Amundsen–Scott South Pole Station's IceCube Neutrino Detector has more than 80 "strings" of sensors reaching as deep as 2,450 meters (8,038 feet) beneath the ice. It is the largest neutrino detector in the world.

Ecosystems at the South Pole

Although the Antarctic coast is teeming with marine life, few biologists conduct research at the Amundsen–Scott South Pole Station. The habitat is far too harsh for most organisms to survive.

In fact, the South Pole sits in the middle of the largest, coldest, driest, and windiest desert on Earth. More temperate parts of this desert (called either East Antarctica or Maudlandia) support native flora such as moss and lichen, and organisms such as mites and midges. The South Pole itself has no native plant or animal life at all. Sometimes, however, seabirds such as skuas can be spotted if they are blown off-course.

Exploration

The early 20th century's "Race to the Pole" stands as a symbol of the harrowing nature of polar exploration.

European and American explorers had attempted to reach the South Pole since British Capt. Robert Falcon Scott's expedition of 1904. Scott, along with fellow Antarctic explorers Ernest Shackleton and Edward Wilson, came within 660 kilometers (410 miles) of the pole, but turned back due to weather and inadequate supplies.

Shackleton and Scott were determined to reach the pole. Scott worked with scientists, intent on using the best techniques to gather data and collect samples.

Shackleton also conducted scientific surveys, although his expeditions were more narrowly focused on reaching the South Pole. He came within 160 kilometers (100 miles) of the pole in 1907, but again had to turn back due to weather.

Scott gathered public support and public funding for his 1910 Terra Nova expedition. He secured provisions and scientific equipment. In addition to the sailors and scientists on his team, the Terra Nova expedition also included tourists—guests who helped finance the voyage in exchange for taking part in it.

On the way to Antarctica, the Terra Nova expedition stopped in Australia to take on final supplies. Here, Scott received a surprising telegram from Norwegian explorer Roald Amundsen: "Beg leave to inform you Fram [Amundsen's ship] proceeding Antarctic."

Amundsen was apparently racing for the pole, ahead of Scott, but had kept all preparation secret. His initial ambition, to be the first to reach the North Pole, had been thwarted by American explorers Frederick Cook and Robert Peary, both of whom claimed to reach the North Pole first. (Both claims are now disputed, and Amundsen's flight over the North Pole is generally recognized as the first verified journey there.)

The Terra Nova and Fram expeditions arrived in Antarctica about the same time, in the middle of the Antarctic summer (January). They set up base camps about 640 kilometers (400 miles) apart. As they proceeded south, both expeditions established resupply depots with supplies for their return journey. While Scott's team stuck to a route forged by Shackleton years earlier, Amundsen took a new route.

Scott proceeded with scientific and expeditionary equipment hauled by dogs, ponies, and motor sledges. The motorized equipment soon broke down, and the ponies could not adapt to the harsh Antarctic climate. Even the sled dogs became weary. All the ponies died, and most members of the expedition turned back. Only four men from the Terra Nova expedition (including Scott's friend Wilson) proceeded with Scott to the pole.

Amundsen traveled by dogsled, with a team of explorers, skiers, and mushers. The foresight and navigation paid off: Amundsen reached the pole in December 1911. He called the camp Polheim, and the entire Fram expedition successfully returned to their resupply depots, ship, and Norway.

More than a month later, Scott reached the South Pole, only to be met by Amundsen's camp—he had left a tent, equipment, and supplies for Scott, as well as a note for the King of Norway to be delivered if the Fram expedition failed to make it back.

Disheartened, Scott's team slowly headed back north. They faced colder temperatures and harsher weather than Amundsen's team. They had fewer supplies. Suffering from hunger, hypothermia, and frostbite, all members of Scott's South Pole expedition died fewer than 18 kilometers (11 miles) from a resupply depot.

American explorer Richard E. Byrd became the first person to fly over the South Pole, in 1926, and the Amundsen–Scott South Pole Station was established 30 years later.

However, the next overland expedition to the South Pole was not made until 1958, more than 40 years after Amundsen and Scott's deadly race. The 1958 expedition was led by legendary New Zealand mountaineer Sir Edmund Hillary, who had become the first person to scale Mount Everest in 1953.

Transportation to the South Pole

Almost all scientists and support personnel, as well as supplies, are flown in to the South Pole. Hardy military aircraft usually fly from McMurdo Station, an American facility on the Antarctic coast and the most populated area on the continent. The extreme and unpredictable weather around the pole can often delay flights.

In 2009, the U.S. completed construction of the South Pole Traverse. Also called the McMurdo-South Pole Highway, this stretch of unpaved road runs more than 1,600 kilometers (995 miles) over the Antarctic ice sheet, from McMurdo Station to the Amundsen–Scott South Pole Station. It takes about 40 days for supplies to reach the pole from McMurdo, but the route is far more reliable and inexpensive than air flights. The highway can also supply much heavier equipment (such as that needed by the South Pole's astrophysics laboratories) than aircraft.

Resources and Territorial Claims

The entire continent of Antarctica has no official political boundaries. Seven countries made defined claims to Antarctic territory prior to the Antarctic Treaty of 1959, which does not legally recognize any claims.