1 of 10

Sensor-Toting SealCall it a polar ice cap of a different sort—a Weddell seal sports an oceanographic sensor in McMurdo Sound, Antarctica, in 2010. When seals dive under the ice in search of food, the sensors attached to their heads collect data on the surrounding water's conductivity, temperature, and depth. This information is transmitted via satellite to scientists researching the physical processes of Antarctica's oceans. What's more, the technology gives scientists a peek into the lives of the world's southernmost seals, including how they locate and capture prey. Since 1968, more than 15,000 animals have been tagged—one of the longest running field experiments of long-lived mammals, according to the U.S. National Science Foundation's Office of Polar Programs. Sensor-toting seals are only one of several experiments that scientists have set up on Earth's chilliest outpost since the early 20th century, when pioneering expeditions first probed the Antarctic interior. (See "South Pole Travel Heats Up on 100th Anniversary of 'Discovery.'") "It's only a hundred years ago when the first expeditions went there, [and we've] only had bases there for about 50 years now, [but] the [scientific] advances made are huge," said John Turner, a climate scientist at the British Antarctic Survey. In 2010, Antarctica housed 111 scientific research stations representing dozens of countries, none of which can lay claim to the continent, according to the Council of Managers of National Antarctic Programs. "It's still an extremely harsh environment; you have to be very careful. One of the big challenges is to keep it pristine," added Turner, who also works with the nonprofit the Scientific Committee on Antarctic Research. "This is a continent for science." —Christine Dell'Amore

Photograph courtesy Daniel Costa