Definition of thermokarst in US English:

thermokarst

noun

Geology
  • A form of periglacial topography resembling karst, with hollows produced by the selective melting of permafrost.

    • ‘Warming of permafrost, thawing of ground ice, and development of thermokarst terrain have been documented over the past several decades.’
    • ‘Deep permafrost thawing may result in irregular surface subsidence and thermokarst pits and mounds.’
    • ‘The forest owes its appearance to an adjacent lake, one of a number of thermokarst lakes in the region.’
    • ‘As the permafrost was deepest under this island, the depression in the mineral sediments probably indicates thermokarst formation in response to conditions created by winter snow accumulations during the island's development.’

Pronunciation

thermokarst

/ˈTHərməˌkärst/