<P> The Northwest Passage (abbreviated as NWP) is, from the European and northern Atlantic point of view, the sea route to the Pacific Ocean through the Arctic Ocean, along the northern coast of North America via waterways through the Canadian Arctic Archipelago . The eastern route along the Arctic coasts of Norway and Siberia is accordingly called Northeast Passage (NEP). </P> <P> The various islands of the archipelago are separated from one another and from the Canadian mainland by a series of Arctic waterways collectively known as the Northwest Passages or Northwestern Passages . </P> <P> For centuries, European explorers sought a navigable passage as a possible trade route to Asia . An ice - bound northern route was discovered in 1850 by the Irish explorer Robert McClure; it was through a more southerly opening in an area explored by the Scotsman John Rae in 1854 that Norwegian Roald Amundsen made the first complete passage in 1903--1906 . Until 2009, the Arctic pack ice prevented regular marine shipping throughout most of the year . Arctic sea ice decline has rendered the waterways more navigable for ice navigation . </P> <P> The contested sovereignty claims over the waters may complicate future shipping through the region: the Canadian government maintains that the Northwestern Passages are part of Canadian Internal Waters, but the United States and various European countries claim that they are an international strait and transit passage, allowing free and unencumbered passage . If, as has been claimed, parts of the eastern end of the Passage are barely 15 metres (49 ft) deep, the route's viability as a Euro - Asian shipping route is reduced . A Chinese shipping line is planning regular voyages of cargo ships using the passage to the eastern United States and Europe, after a successful passage by Nordic Orion of 73,500 tonnes deadweight tonnage in September 2013 . Fully loaded, Nordic Orion was too large to sail through the Panama Canal . </P>

Why did european explorers seek a northwest passage