One of the most quiet volcanoes in Iceland had earthquake swarm today (17.09.2012). I am not aware of any major earthquake activity in Tindafjallajökull volcano during the past 20 years. I am not sure that if there has been any earthquake activity in Tindafjallajökull volcano during this time. One off-earthquake might have happened once in a while. As they do with every volcano in Iceland from time to time. It is unclear why this earthquake swarm took place. But this might be due to stress changes in the area. Rather then anything volcanic taking place in Tindafjallajökull volcano.
Activity in Tindafjallajökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.
The largest earthquake in this swarm had the magnitude of 1.1. The depth of this earthquake swarm was from 10.7 km and up to 3.1 km. This earthquake swarm appears to be over by now.
Katla volcano
The image above also shows earthquake activity in Katla volcano. This earthquake activity is well below what did happen in May to end of July this summer (2012) in Katla volcano. Currently the activity in Katla volcano is low and has been so for many weeks now. I am not expecting that change without some increase in smaller earthquakes first. For the moment, everything is quiet in Katla volcano.