Figure 2.

Map of the volcanic systems of Iceland, adapted from [5,6]. The volcanic systems are numbered. The active rift zones sit within the bands of relatively young basalt (<0.8 Ma) and are labelled: NVZ—Northern Volcanic Zone; EVZ—Eastern Volcanic Zone; WVZ—Western Volcanic Zone; REP—Reykjanes Peninsula. Most of the work described in this paper is based on a study of the Krafla and Theistareykir volcanic systems, numbered 23 and 24 respectively. The dashed line is based on [7] and encircles the rift zone volcanoes that sit on crust that is >35 km thick. The crust under the Reykjanes Peninsula (systems 1–3) and Krafla/Theistareykir is about 20 km thick. This study focuses on the active rift zones of the NVZ, WVZ and REP outwith the dashed line. (Online version in colour.)