This is a short update since this situation is developing quickly.
No eruption has started at the writing of this article. Harmonic tremor is slightly lower compared to when it started at 14:20 UTC in Krýsuvík volcano. This drop in harmonic tremor started around 16:00 UTC. This harmonic tremor is ongoing as for writing of this article. There are no signs of the rift valley formation on the surface yet, but it does show up on measurements, both GPS and satellite measurements. Earthquake activity is high at the writing of this article but most earthquakes are small in magnitude but there are few earthquakes with magnitude of Mw3,0.
Web cameras of the possible eruption area can be found in this locations.
I am going to add more streams as I find them online.
I’ll update soon as possible if anything happens. This situation is changing quickly.