Arctic Circle level, although in mountainous regions there is often no direct view of the true horizon. Only four million people live north of the Arctic Circle due to the severe climate; nonetheless, some areas have been settled for thousands of years by indigenous peoples, who today make up 10% of the region's population. Tens of thousands of years ago, waves of people migrated from eastern Siberia across the Bering Strait into North America to settle. The largest communities north of the Arctic Circle are situated in Russia, Norway and Sweden: Murmansk (population 307,257), Norilsk (175,365), Tromsø (71,295), Vorkuta (59,231) and Kiruna
Petroleum exploration in the Arctic territory, boosting Russia's claim over the oil-and-gas rich triangle. The territory contained 10bn tonnes of gas and oil deposits, the scientists said. Greenland is believed by some geologists to have some of the world’s largest remaining oil resources. Prospecting is taking place under the auspices of NUNAOIL, a partnership between the Greenland Home Rule Government and the Danish state. U.S. Geological Survey found in 2001 that the waters off north-eastern Greenland, in the Greenland Sea north and south of the Arctic Circle, could contain up to of oil. Greenland has offered 8 license blocks for tender along its west coast