Photoglossary

Tephra

Ash and coarse fragments thrown out by a volcano during an eruption. In glacierised areas these layers are preserved in glaciers, deforming slowly during ice flow.

Black tephra derived from subglacial volcanoes under the Vatnajökull icecap exposed on the surface of an iceberg floating in Jökullsaarlon, southern Iceland. Photo J. Alean.

Back