Volcano and earthquake activity in Iceland
Yesterday (19-November-2022) at 21:13 UTC an earthquake swarm started in Katla volcano. This was a small earthquake swarm with just few earthquakes, but it had an earthquake with magnitude of Mw3,2 taking place at 21:13:05. Just before and after this earthquake fewer smaller earthquakes took place.
Since this earthquake activity stopped, everything has been quiet in Katla volcano.
Early morning today (10-November-2022) an swarm of earthquakes took place slightly north of the place where the eruption in August 2022 took place in Fagradalsfjall volcano. This possible dyke intrusion was small and only lasted for about 1 hour before it stopped. Depth of the earthquakes was from 5 km to 7 km.
This activity might give a clue on in what area next eruption is going to take place in Fagradalsfjall mountain. Based on earlier eruption there won’t be any warning before an eruption earthquake swarm starts. In August that eruption started with a minor earthquake swarm, created from a dyke intrusion that was happening. In the hours before an eruption starts there’s going to be a strong earthquake swarm, based on what happened just before the eruption in August. It is interesting if the eruption activity moves north-east, rather than south-west. Why that happens, if it does so, is not something I am clear on why happens.
Today (3-November-2022) at 11:06 UTC an earthquake with magnitude of Mw3,2 took place in Tjörnes Fracture Zone. This earthquake took place a bit of a distance from land. This earthquake seems to be part of an activity that is now happening in Tjörnes Fracture Zone. This seems to be an ongoing earthquake swarm in this area.
It is difficult to know what this earthquake activity means, if it means anything. Its been a while since Tjörnes Fracture Zone had a strong earthquake above Mw6,0 in this area and north of it. Earthquakes in Tjörnes Fracture Zone can go up to Mw7,0 in magnitude, those are rare and happen only after a long time period of quiet it seems.
Today (31-October-2022) at 15:00 UTC an earthquake with magnitude Mw3,2 took place at Herðubreið mountain. This earthquake started a swarm just east of the earthquake swarm that has been going on for more than a week now. Earthquake activity remains high at the writing of this article.
It is unclear what is going at this area. This looks like a tectonic earthquake activity, but there might be more in this than appears. At the moment, this is just earthquake activity and its unknown if that is going to change.
During the night of 27-October-2022 an earthquake with magnitude of Mw4,0 took place at 02:13 UTC. This earthquake was followed by few minor earthquakes. This earthquake was also felt in Grímsey island and in Akureyri town.
There’s a good chance of more earthquake activity in this area. Since this seems to connected to or be part of an earthquake swarm that started on 8-September-2022.
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Sometime yesterday (24-October-2022) a change happened in the earthquake swarm close to Herðubreið mountain. I am not sure when that change happened and it probably took few hours to happen before I detected it. But the change seems to be that now the earthquake swarm is at two locations and not just one. The second change is that the earthquake swarm is now getting more intense. The earthquakes at the writing of this article are minor, only magnitude Mw0,0 to Mw2,7 at the strongest. Nothing above Mw3,0 so far, but that might change without warning. Depth of this earthquake swarm is around 2 to 3 km at the writing of this article.
What is going to happen next is impossible to know. An eruption in this area has not happened for at least 12.000 years or even longer. I don’t know if stronger earthquake activity is required for this area for an eruption to happen. It already is rather fractured from older earthquake activity and rift activity, that makes it possible for magma to have easier paths to the surface without much earthquake activity. That is at least one idea on the situation in this area. I might be wrong on this, since I don’t have information on the finer details of the crust around Herðubreið mountain.
This morning on 23-October-2022 an earthquake swarm took place in west part of Fagradalsfjall volcano. Largest earthquake in this swarm so far had a magnitude of Mw3,0.
This earthquake activity is the result of magma pushing up into the crust at around 5 km depth. This is not a large dyke intrusion and possibly won’t result in a eruption, unless there’s a sharp increase in earthquake activity and that has happened (the August 2022 eruption started this way). This is currently a situation that requires monitoring for changes. If anything is going to happen is impossible to know.
During the night of 23-October-2022 an earthquake swarm started north of Herðubreið mountain. This looks like a tectonic earthquake swarm, rather then a magma related activity. At the writing of this article, over 500 earthquakes have been recorded.
Largest earthquake at the writing of this article had a magnitude Mw4,0 and one magnitude Mw3,1 earthquake took place. Second largest earthquake had a magnitude of Mw3,3. This earthquake swarm is ongoing at the writing of this article and there’s still a risk of larger earthquakes happening north of Herðubreið mountain. The largest earthquake was felt in Akureyri according to news reports.
Today (21-October-2022) an earthquake swarm took place in Brennisteinsfjöll volcano. Largest earthquake had a magnitude of Mw3,0 at 10:23 UTC. This earthquake swarm is possibly over, it is however difficult to be sure.
This is probably just a tectonic earthquake activity. But it is worth noting that volcano activity as has been seen in Fagradalsfjall volcano (Iceland newest volcano) is going to move east on Reykjanes peninsula. How fast and how long that change is going to happen is not known because of lack of data and written records from 700 to 900 years ago are incomplete and vague on details at best.
Today (19-October-2022) at 10:26 UTC an earthquake with magnitude of Mw3,8 took place and at 11:58 UTC an earthquake with magnitude of Mw3,3 took place at the same location. I don’t know if any of the larger earthquakes where felt. A swarm of smaller earthquakes took place and that activity is ongoing when this article is written.
This earthquake activity probably is continuation of an large earthquake swarm that started in that area in September. I don’t know if this is going to result in more stronger earthquakes, but that is a possibility.