Status of the earthquake swarm in Nafir volcano east of Grímsey island in Tjörnes Fracture Zone (TFZ) at 15:53 UTC on 18-February-2018

Welcome to the longest article title (this might be like this for a while). Information here might go outdated quickly as the situation changes.

Currently the earthquake swarm is smaller today (18-February-2018) then yesterday (17-February-2018) with mostly small earthquakes happening. Largest earthquakes since midnight had the magnitude of 3,4 at 12:14 UTC. It remains unclear if this earthquake swarm is going to increase again, but at the moment it is currently ongoing.


The earthquake swarm east of Grímsey island. Copyright of this image belongs to Icelandic Met Office.


The earthquake activity is less dense today than yesterday. Copyright of this image belongs to Icelandic Met Office.

It is difficult to know what happens next in this area due to the fact that this area is under the ocean and is really complex due to mixture of tectonic earthquakes (strike-slip activity) and volcano earthquake activity. What seems to be going on now is a volcanic earthquake activity. There is no magma signature at the moment because magma has not started to flow to the surface. It remains a question if it is just a question of time now if that happens. There is no documented eruption history in this area and that makes everything little bit more difficult.

This article is going to be updated if needed.

Article updated at 16:22 UTC. Text fixes.

29 Replies to “Status of the earthquake swarm in Nafir volcano east of Grímsey island in Tjörnes Fracture Zone (TFZ) at 15:53 UTC on 18-February-2018”

  1. Thanks for the update(s).

    More stuff happening. (around 18:11, 18:27). The signature in the drumplots looks a bit different from the earlier green stars in this swarm?

    1. The M3.4 earlier today (12:14) had the same character. Not as ‘spiky’ as the earlier ones.

  2. Storm warning for the next 12 hours in Iceland.
    Serious storm warning for Iceland on Wednesday until Saturday or Sunday (two low pressure system passing over Iceland).

    If you are in Iceland. Please keep track on the weather. The weather on Wednesday is going to be extremely bad.

  3. Thank you very much Jon and everyone who posts, as very much an amateur, I am learning a lot more about earthquakes. Fascinating. Hope the low pressure systems aren’t as bad as expected for everyone in Iceland.

  4. They must be nervous now at Grimsey. I guess there are evacuation plans. But they certainly have low flexible houses. There are about 80 people living on that island.

  5. Thanks to you all for keeping us informed! Giving these info to a wordwide eq-forum and hoping this is ok? Otherwise I will stop 🙂

  6. I am going to write a new short article soon. First I will save the earthquakes from the strong swarm early this morning. It is going to be difficult due to how dense this earthquake swarm was, around ~5 earthquakes each minute and a magnitude 2,5> every five minutes.

  7. It looks like this swarm is not going to go quiet – they are rolling in unabated at an average of more than one per minute. I read that this is now the largest swarm in the area since 1988, and who knows what could happen next. Could we have a Surtsey-style eruption or is this the prelude to a massive, 1910-style quake in the TFZ?

  8. The Civil defence and emergency unit of Iceland has just declared “uncertainty level” due to the earthquakes in Northern Iceland

  9. Hey everyone, I saw this thread at the world-earthquakes chat. Nice conversation! The swarm started on 27/1 but today was (so far) the peak day. As much as 2-3/quakes per minute on the early hours UTC today, several above M3! M5.0 (USGS) was the largest one. Lasted at maximum intenisty a few hours, but after the M6.0 in Mexico it went down. It could go up again within the next few days though! Really interesting indeed.

      1. Ended? No such thing. Just that the levels alters. It could end any time, but not yet.

    1. I said pretty much ended and doesn’t mean ended. The peak (for now) ended few minutes before the Mexico quake.. Why are you making this such a big deal? I was the one who said ‘It could go up again within the next few days ‘ so why would I say it ended? I think you assume stuff I never wrote or said. Anyways, have a good day..

  10. What is the antipode for Iceland?
    Quakes can occur on the antipode – opposite side of Earth – and often do

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