The Askja Route

The long and difficult route to the huge Askja caldera takes you through a landscape of contrasts, from jagged black volcanic plains and mountains to yellow pumice, with vistas over Vatnajökull icecap.

Pumice is a textural term for a volcanic rock that is a solidified frothy lava typically created when superheated, highly pressurized rock is violently ejected from a volcano. It can be formed when lava and water are mixed. This unusual formation is due to the simultaneous actions of rapid cooling and rapid depressurization. The depressurization creates bubbles by lowering the solubility of gases. The simultaneous cooling then freezes the bubbles in the matrix.