Largest active Arctic sand dunes

The largest active sand dune field in the Arctic is the Great Kobuk Sand Dunes (GKSD) located in Kobuk Valley National Park in Alaska, USA, covering an area of approximately 62 square kilometres (23.9 square miles). The GKSD is located at 67°N, about 35 miles (56 kilometres) north of the Arctic Circle.

Temperatures at the GKSD can vary from as high as 100 degrees Fahrenheit (37 degrees Celsius) in the summer to -50 degrees Fahrenheit (-45 degrees Celsius) in the winter.

Combined with the nearby Little Kobuk Sand Dunes (LKSD) and the Hunt River Sand Dunes, the area of dune coverage rises to around 77 square kilometres (30 square miles).

Dunes in this region are thought to have been formed during the last Ice Age as a result of sand and silt – left behind by receding glaciers – being picked up by the wind and deposited in the Kobuk Valley.