Fault ruptures and geothermal effects of the second earthquake, 29 May 2008, South Iceland Seismic Zone

Our results fit with the lineations in the aftershocks and with fault plane solutions. They also show that the 2008 source fault ruptured within a 2-km wide deformation zone where previous earthquakes and changes to geothermal activity have occurred at least since 1706. This implies that major earthquakes in this area may have a common source fault at depth and a wider deformation zone at the surface. Our study demonstrates how transform faulting at the junction of a rift segment causes recurring medium-large earthquakes that control fault behavior and permeability in fractured geothermal fields.