Torfajökull

Torfajökull is a rhyolitic stratovolcano, caldera and complex of subglacial volcanoes, located north of Mýrdalsjökull and south of Þórisvatn Lake, Iceland. Torfajökull last erupted in 1477 and consists of the largest area of silicic extrusive rocks in Iceland.

The volcano's eruption around 870, a combined bimodal eruption with additional engagement of the Bárðarbunga-Veiðivötn volcanic system, has left a thin layer of easily recognized mixed tephra all over Iceland. This layer makes it possible to determine the exact dates of many archeological finds by so called tephrochronology, like in the Reykjavík 871±2 museum.