Siberia facts

The soil. The permafrost prevents trees from developing a deep root system. Climate variations or forest fires can thaw the upper extents of the permafrost, creating a ground slump called thermokarst.

Underground monster. 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.

1500 m. In areas of harsh winters the depth of the permafrost can be as much as 1,493 m (4,898 ft) in the northern Lena and Yana River basins. The overlying active layer that seasonally thaws is just 0.6–4 m (2.0–13 ft) thick.

Moscow and Vladivostok. The Trans-Siberian Railway has connected Moscow to Vladivostok since 1916, and is still being expanded. With a length of 9,289 kilometres, it is the longest railway line in the world.

Off the coast of Siberia. The Transpolar Drift Stream is a major ocean current of the Arctic Ocean, transporting sea ice from the Laptev Sea and the East Siberian Sea towards Fram Strait. Drift experiments with ships like Fram or Tara showed that the drift takes between two and four years. It has been cited as a major factor in the North Atlantic Oscillation and Arctic oscillation atmospheric changes.