The movement of large amounts of sea ice across the Arctic Basin, at 1–4 cm/s, from the Siberian coast through the Fram Strait, to the north-east of Greenland, and down the eastern coast of Greenland. The transpolar drift is driven by the Beaufort Gyre, an anticyclonic circulation of water mainly confined to the uppermost 300 m, over the Canadian Basin, off Canada and Alaska. One effect of the transpolar drift is to pile up ice along the northern coasts of Canada and Greenland, where in places it is up to 8 m thick.