When things gets busy in Iceland, they mean it. At least that is the case now. This also the reason why I do not trust the quiet times in Iceland.
A earthquake with the size of ML3.4 took place 25 km east of Grímsey Island in the TFZ at 21:46 UTC. But that is an non-volcanic zone that bridges the eastern volcanic zone with the North-Atlantic rift zone. This earthquake had an earthquake with the size of ML2.9 taking place before the larger one. That was an pre-earthquake most likely. But it seems that an earthquake swarm is also starting in TFZ as it has done close to Krísuvík volcano on the Reykjanes Ridge. I do not know if this earthquake was felt or not.
I am going to update this blog post if I need to.
Update 1: The location of this earthquake. So far there have not been any aftershocks following the ML3.4 earthquake. Its depth was at 11.5 km. This earthquake does not appear clearly on my geophones due to the distance involved (over 200 km).
Blog post updated at 22:22 UTC.