BBC correspondent Jessica Parker has flown over Iceland’s Reykjanes Peninsula, where the recent volcanic activity has been concentrated.
Scientists say the area could face decades of increased volcanic instability.
Fears of an impending eruption led to the evacuation of the town of Grindavik, which has partially sunk by more than a metre.
It is thought that magma is running underneath a previous, centuries-old, visible fissure seen in aerial photographs.
Iceland’s biggest bulldozer is heading to the small fishing town to build defences to stop lava from a volcano destroying key buildings.
One of the country’s most famous tourist attractions, the nearby Blue Lagoon, will remain closed until the end of this month.