This is a short update and this information might go outdated quickly.
It appears that the eruption that took place in Bárðarbunga volcano was a minor one. It also looks like that the eruption was so small that it didn’t even make dent in the glacier on top of it, but the glacier in this area is around 400 meters thick. Such minor eruptions are not common in Iceland, but they do happen once in a while.
Earthquake activity today (23-August-2014) in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.
Largest earthquake today had the magnitude of 4,5 (EMSC information here) – 4,7 (USGS). Other earthquakes that have taken place today have been smallers, few earthquakes with magnitude above 3,0 also took place today.
The harmonic tremor that took place in Bárðarbunga volcano today. It makes a clear mark from the other magma movement that has been taking place during the past week. This is Dyngjuháls SIL station. Copyright of this image belongs to Icelandic Met Office.
This harmonic tremor was also visible on Kreppuhraun SIL stations. Copyright of this image belongs to Icelandic Met Office.
GPS data showing current inflation on Dyngjuhjáls. More plots can be found here. Copyright of this image belongs to University of Iceland.
Current GPS data show that inflation to the north has stopped, while inflation to the west has increased and up to 2 to 3 cm a day based on newest GPS data. This means that more magma is flowing into the dyke on 5 to 10 km depth. The dyke continues to extent, but now it is moving more north rather then north-east as before.
The eruption that took place today was a minor one. I am not even sure it lasted a whole hour, but since it was under a 400 meter thick glacier that is only guess work on my end based on tremor data that I have. This might however not be the last eruption in Bárðarbunga volcano, far from it. Short eruptions like this one might happen on regular basis now in Bárðarbunga volcano and not all of them are going to take place under glacier in my view.