Almannavarnir put out a warning yesterday (19-May-2015) about increased risk of man made earthquakes in Hengill volcano. This happens when a water is pumped down into the ground it changes the pressure in the rock and creating earthquakes as a consequence. There is a risk of earthquakes with magnitudes up to 4,5 or larger. The first pumping down of this leftover water is expected to end by 19-June-2015.
Icelandic News about this