Today (5-October-2016) a minor earthquake swarm took place in Bárðarbunga volcano. Largest earthquake in this swarm had the magnitude of 3,8 and the second largest earthquake had the magnitude of 3,0. Other earthquakes where smaller in magnitude.
The earthquake activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.
The reason for this earthquake activity is inflation in Bárðarbunga volcano. This is pushing the crust that fell down in the eruption of 2014 – 2015 in Bárðarbunga volcano (Holuhraun area) up again and that friction creates earthquakes. New magma is flowing into shallower magma chamber (at depth of ~10 km) from more depth under the volcano (20+ km depth). This started in September-2015 and is going to continue for many more months, maybe until next eruption in Bárðarbunga volcano.