This is a short update and information here might go outdated quickly and without warning. This update is written on 22. December 2023 at 20:50 UTC.
Inflation has resumed in Svartsengi volcano. It also seems that inflation started again just before the eruption ended in Sundhnúkagaígar. At the writing of this article, the inflation is only around 5mm to 8mm a day. That is fast, by any standard, but still lower than before the eruption when inflation was around 10mm a day. There seems to be a slowdown of inflation before an eruption happens and a new dyke creations. Not all dyke that are going to happen are going to end in a eruption, maybe, since the magma has only limited space to expand into in the rift valley, because of the dyke that was created on 10. November 2023.
Earthquake activity along the rift valley increased quickly as the eruption that started on 18. December 2023 started to slow down. That means the magma in Svartsengi volcano is trying to find a way out and erupt all at once, or close to that in my personal view. The 4,1 km long fissure that erupted last time doesn’t seems to have been a enough for the pressure that is in the volcano at the writing of this article. That is interesting but might also be a clue that things are about to get really dangerous in this area. I also don’t know if this is going to happen, because clues are one thing and reality is a different thing.
If anything happens. I am going to write an article soon as I can.
Non-science comment: I previously mentioned a psychic who had a vision of a “melt-through” of a large underground rock “plug” during this eruption cycle. This seemed useless to me because it could be interpreted many ways and would be impossible to verify. However, Jón’s info that the magma is more “evolved” than what came out in the last 2400 years gives me pause. Perhaps the [evolved] magma path in question is relatively old and until now has [indeed] been plugged. I’m not sure what that means, but intuitively this seems consistent with a larger eruption (i.e., a rare/major event). The earthquake activity may indicate the crust is splitting further open, which will only reinforce the cycle. If so, this eruption will only end with depletion of the relevant (deep?) magma chamber(s), or release of the (local) accumulated geophysical tension, or both.