Observations on nearshore pingo growth, Adventdalen, Spitsbergen

The open-system pingos of Svalbard can be divided into three groups. Group I pingos are located over geologic faults. Group II pingos are located in areas of artesian flow resulting from the migration of sub-glacial groundwater. Pingos of group II occur usually in riverbeds, where the permafrost is locally thinner. Group III pingos are located in nearshore or low-lying environments of active geologic uplift, where groundwater flow is in response to relict conditions. In this paper group III pingos in the Adventdalen delta area are examined. Group III pingos characteristically have a complex shape and occur in groups. Growth occurs rapidly after initial emergence from marine conditions and the establishment of a minimum permafrost thickness. Water is supplied through discontinuities in the aggrading permafrost. Net influx of water is moderate, owing to relatively thin permafrost.