Yesterday (17.01.2012) an small earthquake swarm started in Hengill volcano. This earthquake is in the area where Orkuveita Reykjavíkur (OR) has been pumping down cold water from the hydro-thermal power plant that they have in the area. So far the largest earthquake in this minor earthquake swarm is just ML2.0 in size according to automatic size estimation. The depth of this earthquake swarm is around 5 km.
The earthquake activity in Hengill volcano today and yesterday (17.01.2012 and 18.01.2012). Copyright of this picture belongs to Iceland Meteorological Office.
The earthquake activity in this area repeats it self regularly due to water being pumped down into the ground. This has increased the risk of large (Mb5.0 or larger) earthquake in this area. But it is impossible to be sure if such events take place. As this is most likely just going to speed up an process that is already in place by nature forces in Hengill volcano (earthquakes, nothing else). So for the moment, the only thing that can be done is to wait and see what happens next.