I really did think that a eruption was about to start in Hamarinn volcano yesterday. As the signal that I was seeing was not far from what I did see on 12 July, 2011 when a eruption did take place for sure in Hamarinn volcano.
Here is the tremor signal from 12 July early in the morning.
Here is the signal on the 27 September, 2011.
The tremor signal in July was stronger, but it looks almost the same way as the signal yesterday (27 September, 2011) did. So I think I know what did happen yesterday (27 September, 2011) in Hamarinn volcano. There might have been a minor dike intrusion into Hamarinn volcano. There where no earthquakes as it might have been going up resistance free pathway. But it is hard to know that for sure at the moment. Later events might however make what happened yesterday more clear what did happen on 27 September, 2011.
Note: I am looking for data on El Hierro volcano. As I am going to make a special blog post about it soon. I am looking for everything that I can get my hands on and might be useful to me.
Note 2: I have updated this blog post here and added the most recent eruptions in Iceland. Blog post: A short history of volcano eruptions in Iceland
Blog post updated at 12:59 UTC on 28 September, 2011.