Theory of the ice-free Arctic Ocean

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Map with the presumed open sea at the North Pole
The extent of the Arctic ice sheet in 2007 compared to previous years
Fluke of a narwhal in a polynya in Baffin Bay

The theory of the ice-free Arctic Ocean was a theory popular in the 19th century, which was clearly refuted towards the end of the same, which stated that an ice-free, navigable zone should exist around the North Pole .

The origins of the theory go back to the 16th century on Robert Thorne († 1527). Also Willem Barents and Henry Hudson based their expeditions to explore the Northeast and the Northwest Passage to this theory.

After more and more polar explorers on their expeditions in the north were trapped in the thick ice layer of the Arctic Ocean up to the middle of the 19th century and this was an insurmountable barrier for the ships of the time, it was almost forgotten before the explorers Elisha Kent Kane , Isaac Israel Hayes and George W. DeLong had advanced beyond the 80th parallel on their expeditions and their reports of having discovered ice-free zones (now known as polynjas ) made researchers of their time sit up and take notice.

Kane and Hayes argued that because the ice floes by the drift to the south wandered near the pole an ice-free zone must exist. They suspected entry into this navigable area of ​​the Arctic Ocean via the Kennedy Canal , later through the Robeson Canal , both parts of the Nares Strait , which separates Ellesmere Island from Greenland and connects Baffin Bay with the Lincoln Sea in the Arctic Ocean.

Matwei Gedenstrom, however, suspected the entrance to the north of Siberia and based this theory on his expedition with Jakow Sannikow . The two of them came across large polynyas while mapping the New Siberian Islands from 1808–1810 . Furthermore, they described " Sannikow-Land ", an unknown land mass north of the Kotelny Island , which was supposedly discovered by the two but does not exist, as ice-free.

Further arguments for the theory were provided by the theory, which has meanwhile also been proven to be false, that sea ​​ice only forms in regions close to land, but not on the open sea. Since no land was suspected near the pole, this area should have been free of ice.

19th century scientists Matthew Fontaine Maury and August Petermann , who studied ocean currents , argued that warm currents to the north, like the Gulf Stream and Kuroshio , would rise below the surface and melt the pole ice. Even temperature measurements showed that around the 80th parallel the lowest temperatures were measured, what is also the observations of animal migrations sought to rely, as they migrated to the north, what the scientists had expected a less hostile space beyond the 80th parallel. Ultimately, it was also believed that the everlasting sun ( midnight sun ) would melt the pole ice during the arctic summer.

When the expeditions of Kanes, Hayes and DeLong failed to prove the theory, belief in the theory of the ice-free Arctic Ocean waned. George Nares , who was the first to succeed in navigating the Nares Strait , presumed entrance to the ice-free zone, as far as the Lincoln Sea, clearly refuted the theory for the first time, because he found nothing but more sea ice. The theory was finally refuted by Fridtjof Nansen and Otto Sverdrup , who drifted through the Arctic Ocean with the Fram from 1893 to 1896.

With regard to the Northeast Passage, the Austro-Hungarian North Pole Expedition of Julius Payer and Carl Weyprecht succeeded in proving the opposite when they reached Cape Fligely on the Franz Josef Land, the northernmost point of Eurasia , but found nothing but sea ice.

Although the theory ultimately turned out to be wrong, it made a significant contribution to the exploration of the Arctic , because, inspired by the idea of ​​a relatively simple way to conquer the pole by ship through an ice-free zone, numerous expeditions were equipped in the 19th century .

Today the theory is being scientifically revived under different circumstances: due to global warming, it is expected that larger areas of the polar ice could melt in the summer months.

After the record year 2007, a year that was too warm on average, a research vessel managed to bypass the North Pole in 2008. The remaining ice could be broken through under its own power. In the summer of 2011, both the Northwest and Northeast Passages were navigable.

See also

literature

Individual evidence

  1. ^ The ice clears the way Press release of the Information Service of Science of August 31, 2011