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Thermokarst pits in undisturbed terrain of the 1002 Area of the Arctic National Wildlife Refuge, east of the Jago River. The numerous small thermokarst ponds (up to ~5 m diameter) are caused by thawing of the upper surface of ice wedges that separate the ice‐wedge polygons. Thermokarst such as this has recently become widespread across large areas of undisturbed tundra in northern Alaska, and is now common on upland surfaces of the 1002 Area (Jorgenson et al. 2018) (photo: M. Nolan).
