Ice chimneys

Ice chimneys – also known as fumarolic ice towers – form over fumaroles. These large structures build up when volcanic gases and steam rise from the fumaroles, condense in the cold air and deposit layers of ice. The chimneys get taller with each layer of ice.

The chimneys vary in size but are usually 6–10 m high and 3–4 m in diameter. They often have ice caves at their base.

The chimneys get their name as steam can sometimes be seen rising from their hollow cores.

This image shows the scale of an ice chimney compared to the person next to it.