Fig. 3

Reference geologic model of Krafla. a Surface geologic map (Sæmundsson 2008) showing mapped faults and fractures (black), eruptive fissures (red), and drilled wells (black dots). The surface traces of Section 1 (N–S, shown in b) , Section 2 (SW–NE, c), and Section 3 (WNW–ESE, d) shown with dashed lines. Subsurface geology based on Weisenberger et al. (2015), with hyaloclastites (yellow), lava flows (blue-green) and basement intrusions (red). Fault structure is calculated based on surface traces and the assumption of near-vertical dips that lessen with increasing depth, and is highly uncertain