There Are 3 South Poles, So Which One Did Prince Harry Reach?

There's the geographic south pole, along with the magnetic south pole and the ceremonial south pole.

Oscar Wisting was one of five Norwegians at the South Pole with explorer Roald Amundsen in 1911.

Prince Harry and a group of 12 servicemen and women from around the world reached the south pole on Friday, organizers have announced.

The group undertook the three-week trek to raise money and awareness for the U.K.-based Walking With the Wounded charity, which helps wounded armed forces members.

The British prince's group ended up at the geographic south pole, the southernmost point on Earth. If you stuck a pole all the way through the planet along its axis of rotation, it would poke out the bottom at the  geographic south pole.

But there's more than one south pole. In fact, there are three.

The geographic south pole is the place where all the lines of longitude converge in the Southern Hemisphere.

Its only marker is a stake with a sign honoring the first explorers to reach the geographic south pole—Roald Amundsen and Robert Scott—in 1911 and 1912, respectively. But since the whole shebang rests on a moving ice sheet, the marker must be repositioned every year to account for the roughly 33 feet (10 meters) of travel per year. (See "South Pole Expeditions Then and Now: How Does Their Food and Gear Compare?")

Other South Poles

The pole your compass points toward when you head south is the magnetic south pole. That pole suffers from a case of wanderlust, moving northwest toward Australia at six to nine miles (10 to 15 kilometers) per year.

The magnetic south pole is defined by where Earth's magnetic field lines come vertically out of the surface of the Earth. Since the field is generated by the rotation of Earth's fluid core, it doesn't always stay in the same place. (Read about how researchers track the magnetic south pole.)

And then there's the ceremonial south pole, which has been set aside for photo opportunities.

A short walk from the geographic south pole, the ceremonial pole is marked by a red and white striped pole topped with a shiny, chrome-colored sphere. The area is surrounded by the flags of the Antarctic Treaty signatory countries.

It too must be moved every year so it doesn't drift too far from the geographic south pole.

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