How did the first men at the South Pole know they were at the South Pole?

Answer 1

When Amundsen arrived at the South Pole in 1911, navigation was a rather more complicated business. Navigation en route was done by dead reckoning, measuring distance with a distance wheel trailing the dog sleds and taking bearings with a compass adjusted for magnetic deviation, which is large and varying in the polar regions.

By the end of a day's travel, the navigator could hope to be within some hundred meters of the intended destination. At regular intervals more exact positions were taken by means of a sextant, a handheld instrument measuring the sun's elevation above the horizon. The solar elevation at noon would give the latitude, while the timing of the solar culmination with a chronometer would give the longitude. Extensive nautical tables and complicated calculations were involved.

At high latitudes the process tends to be even more complicated, because the longitudes converge and the solar orbit appears more and more level in relation to the horizon.

When Amundsen and his team arrived at what they initially estimated to be the South Pole on December 14, 1911, they eventually found themselves a few kilometers off the target. They spent the following three days and nights doing continuous solar observations with sextants and a theodolite, a precision surveying instrument, and eventually closed in on the actual pole with an accuracy of a couple of hundred meters. In 1911 this was quite a feat.

Today, finding your way across the vast emptiness of the Polar Plateau is very simple, with the aid of the satellite-based Global Positioning System (GPS).