The Krafla magma chamber

A magma chamber resides about 2 km below the Krafla caldera.
Magma flows into the chamber from below and the land rises.

When the crust rifts the magma erupts at the surface.
The magma also flows along the fissures deep inside the crust.

(A link to the Volcanoes of the World)

Páll Einarsson 1991. Umbrotin við Kröflu 1975-89 (The Krafla Fires 1975-89). In: Náttúra Mývatns. Hið íslenska náttúrufræðifélag (Icelandic Natural History Society), Reykjavík.