Entering the tunnel. The tunnel was built in the 1960's to study both the permafrost itself and mining and construction technology in the Arctic.
Reticulate-chaotic ice in the middle right of the photo as result of freezing of soils that had been thawed earlier. Ice lenses in the top of the photo.
The end of the tunnel collapsed. There used to be a vertical ventilation shaft out to the surface, but melt water trickling in weakened the permafrost and caused the shaft to collapse.
Foliated ice wedge. Melt water seeps into vertical cracks in the soil and freezes.
Tony standing underneath an ice wedge.