Pingo

A pingo, also called a hydrolaccolith or a bulgunniakh, is a mound of earth-covered ice found in the Arctic and subarctic that can reach up to 70 metres (230 ft) in height and up to 600 m (2,000 ft) in diameter. The term originated as the Inuvialuktun word for a small hill. The plural form is 'pingos'. The term is also used for depressions, often water filled, formed by the melting of ice at the end of the last glaciation. A pingo, also called a hydrolaccolith or a bulgunniakh, is a mound of earth-covered ice found in the Arctic and subarctic that can reach up to 70 metres (230 ft) in height and up to 600 m (2,000 ft) in diameter. The term originated as the Inuvialuktun word for a small hill. The plural form is 'pingos'. The term is also used for depressions, often water filled, formed by the melting of ice at the end of the last glaciation. A pingo is a periglacial landform, which is defined as a nonglacial landform or process linked to colder climates.'Periglacial' suggests an environment located on the margin of past glaciers. However, freeze and thaw cycles influence landscapes outside areas of past glaciation. Therefore, periglacial environments are anywhere that freezing and thawing modify the landscape in a significant manner. They are essentially formed by ground ice which develops during the winter months as temperatures fall.