About the North Pole
The geographic North Pole is a point at 90 degrees latitude in the Arctic Ocean, around 725 km (450 miles) north of Greenland. Here, the sea is more than 4,000 metres deep, although the surface is covered in drifting pack ice.
The Vikings were probably the first people to explore the region but most of their achievements were undocumented. From the 16th century onwards, Russian, English and Dutch mariners explored the Arctic Ocean and its coastlines, searching for navigable passages. Ironically, early Arctic explorers believed that the polar sea would be ice-free. They were invariably disappointed.
A number of 19th-century adventurers had more success, reaching latitudes in the low 80s. In 1893, the Norwegian explorer Fridtjof Nansen set sail for the North Pole in a specially commissioned vessel, the Fram. He allowed the ship to become trapped in pack ice which then drifted northwards. At one point in the three-year voyage, Nansen sledged across pack ice beyond 86 degrees latitude.
A rash of polar expeditions followed at the turn of the century but they all failed. Then, in 1909, an American, Robert Peary, set off for the Pole from Cape Columbia, the most northerly part of Canada. He returned, claiming to have reached the Pole on April 6, accompanied by five companions.
At the same time, a former colleague, Frederick Cook, also returned from the Arctic, claiming that he had reached the North Pole a year earlier. Controversy surrounded both mens claims, since neither could produce independent proof of their navigational calculations. Cooks case disintegrated within a few years. Later analysis of Pearys diary and other records suggested that he probably came within 50-100 km (30-60 miles) of the Pole.
In 1925, Roald Amundsen tried to fly over the North Pole in a pair of flying boats but failed. In May 1926, Amundsen tried again, this time in semi-rigid airship, the Norge, pictured here. He was accompanied by the Italian aeronautical engineer and pilot, Umberto Nobile. The expedition was successful but the pair fell out over who should take credit for the achievement.
In 1928, Nobile led another semi-rigid flight over the Pole but crashed on the ice pack. Nobile survived but Amundsen perished aboard a separate flight to rescue his old colleague and rival.
The first surface expedition to make a confirmed journey to the North Pole was led by an American, Ralph Plaisted, as late as 1968. He and his companions travelled across the ice in snowmobiles and were airlifted from the polar region after their achievement.
On April 6, 1969, Wally Herbert and his British Transarctic Expedition reached the North Pole by dog sleds. Herberts team had taken the long way: they set off from Point Barrow, Alaska, on February 21, 1968, and arrived at Spitsbergen in the Norwegian archipelago of Svalbard on May 29, 1969. They covered 5,800 km (3,600 miles).