The jökulhlaup from Katla in 1918

Abstract

The greatest event in the 20th-century glaciological history of Iceland has been the glacier burst of Katla on Saturday 12 October 1918. Several cubic kilometres of water and ice were transported by the burst, and over 0.5 km3 of magma surfaced from the Katla caldera. The volcanic material was transported by air and water, and part of it probably formed pillow lava at the eruption site. The volcanic material transported by water was deposited mostly on the Mýrdalssandur plain and at the coast, but part of it was probably carried out to greater depths by gravity currents as the water entered the sea. The peak flow rate during the jökulhlaup was probably over 3 × 105 m3 s−1 of water, with a further 25 Kt s−1 of ice and a similar amount of sediment.