There are ice caves that grow and disappear within the edges of the tongue that ruptures out from the Erebus Glacier. Every year they are different, and the mountaineers who work with the Field Safety department discover them and decide whether they are safe for entry.

We went out on snowmobiles, cold air and two-stroke motor exhaust trailing behind us, stopped in sudden silence at the base, stark and soft like bones in the desert. Ethereal rooms with smooth sculptors’ ridges on the walls, fuzzy stalactites of ice dripping from the ceiling. Turquoise to violet ice, moving air in the farthest secret recesses like the glacier breathing on your skin.