Seismic activity surrounding the Bárðarbunga volcano gradually increased from 2007 to 2014 , with a brief pause during the nearby eruption at Grímsvötn in 2011 . By the summer of 2014 activity reached a level similar to that just before the Grímsvötn eruption . In May 2014 there was a small earthquake sequence of about 200 events . GPS data recorded a displacement of 14 cm in the region since the beginning of the phase of unrest , compared to a figure of 2 cm over the rest of Iceland . This displacement is attributed to the separation of two continental plates : the Eurasian Plate in the east and the North American Plate in the west . Further earthquake swarms were detected : one at Bárðarbunga caldera , attributed to subsidence due to the magma chamber emptying ; and another at the head of a dyke which extends approximately 40 km outwards from the vent , at a depth of 5 – 8 km below the surface . Evidence of minor sub-glacial eruptions occurred as early as 23 August when tremors were detected , but it was not until 29 August when lava erupted onto the surface at the fissure , forming a crater and substantial lava field to the north of the glacier in Holuhraun
Grímsvötn in 2011
2011 eruption of Grímsvötn
2014–2015 eruption of Bárðarbunga