Arctic questions

Blue ice occurs under the surface of a glacier as a result of repeated, slow thawing and freezing of water. This process speeds up when snow falls on the top of a glacier, the ice compresses, air bubbles are squeezed out and ice crystals enlarge, making the ice appear blue. In the Greenland environment this process takes from 100 up to 150 years.

An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km2 this is also known as continental glacier. The only current ice sheets are in Antarctica and Greenland; during the last glacial period at Last Glacial Maximum the Laurentide ice sheet covered much of North America, the Weichselian ice sheet covered northern Europe and the Patagonian Ice Sheet covered southern South America.

Auroras are produced when the magnetosphere is sufficiently disturbed by the solar wind that the trajectories of charged particles in both solar wind and magnetospheric plasma, mainly in the form of electrons and protons, precipitate them into the upper atmosphere (thermosphere/exosphere) due to Earth's magnetic field, where their energy is lost.

Greenland is an autonomous constituent country within the Kingdom of Denmark between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for more than a millennium.

The word Arctic comes from the Greek word arktos meaning bear and the adjective arktikos "of the bear". The name refers either to the constellation Ursa Major, the "Great Bear", which is prominent in the northern portion of the celestial sphere, or to the constellation Ursa Minor, the "Little Bear", which contains Polaris, the Pole star, also known as the North Star

The word mammoth comes from the mythology of the Siberian peoples who believed they lived underground - as dead ones were found in the ground from time to time.

The total length of the river is 1982 miles (3190 km). There are only four vehicles-carrying bridges across the Yukon River.

The average discharge of the Yenisei is 19,600 m³/s. It is more than the Mississippi, Ganges or Paraná.

Gunnbjørn Fjeld is Greenland's highest mountain. It is a nunatak, a rocky peak protruding through glacial ice. The mountain is named after Gunnbjorn Ulfsson, the Viking who was the first European to reach Greenland.

Greenland is an autonomous country within the Kingdom of Denmark since the early 18th century. The economy of Greenland strongly depends on Denmark's annual subsidy to the island. The subsidy is slated to diminish gradually over time as Greenland's economy is strengthened by increased income from the extraction of natural resources.