Update on the eruption in Fagradalsfjall mountain on 16-April-2021

This is a short update on the eruption in Fagradalsfjall mountain in Krýsuvík-Trölladyngja volcano system.

There has not been any major change since last update. In this week four new craters started erupting and I write an article about that earlier in this week for more details.

  • It was reported today (16-April-2021) that lava has now started to flow outside of Geldingadalir and to the east. This lava is now flowing over a walking path that people used to get close to the eruption. Getting close to the eruption might not be possible any more. There is also a chance that lava is going to is going to flow to the south of the craters more than it already has done.
  • Swarm of small earthquakes took place north-east in Fagradalsfjall mountain early morning around 06:00 UTC. Largest of those earthquakes had a magnitude of Mw2,8.
  • There is no sign of the eruption ending.
  • There continues to be a high risk of new vents opening up and start erupting without warning.

There are no more reports this week outside of what I did write about what was happening earlier in the week. If anything major happens I am going to post an update soon as possible.

Stronger harmonic tremor reported in Fagradalsfjall mountain eruption

Yesterday (15-April-2021) it was reported (late) that harmonic tremor seems to have been increasing in the eruption since midnight. This normally happens if new craters have opened up. The weather is really bad at the eruption site currently so viewing the eruption with any web camera is difficult if not impossible. Rúv web cameras failed last night because of the weather that has been seeing wind peaks up to 41 meter/second with heavy rain. Current weather forecast is that the weather is not going to start improving until late today (Friday 16-April-2021). The increased tremor might be weather but weather is in general easy to filter out and doesn’t affect the lower bands (0.5 – 1Hz) that much as it does higher bands (2 – 4hz). What is happening won’t be clear until the weather starts getting better.

Information about the volcano Krýsuvík.

News and web cameras that might work

Órói auk­ist en aðstæður óljós­ar (mbl.is, Icelandic)
Gosið í Geld­inga­döl­um í beinni (web camera, mbl.is) – The fog cover sometimes breaks a little on this web camera.

More earthquakes far north of Kolbeinsey island

This morning (15-April-2021) more earthquakes where recorded far north of Kolbeinsey island. This activity is probably outside of Kolbeinsey ridge but I don’t know the name for this part of the north Atlantic ride. Largest earthquake took place at 09:29 UTC and had a magnitude of mb4,4 according to EMSC. Information about the earthquake can be found here.

Green stars out in the ocean where strong earthquake activity is happening
Earthquake activity far north of Kolbeinsey island. Copyright of this image belongs to Icelandic Met Office.

It is not possible to know what is going on at this location. It is extremely remote and under 2 to 4 km deep ocean. If anything more happens at this location it is only going to be detected by seismometers.

Earthquake swarm far north of Kolbeinsey island

Early morning (14-April-2021) an earthquake swarm took place far north of Kolbeinsey island. Largest recorded earthquake had a magnitude of Mw3,5 but it possibly was larger but because of distance from the SIL network the magnitude is underestimated. I did record this earthquake on my only seismometers and it showed a lot of surface wave activity, suggesting a larger magnitude than Mw3,5.

Green stars far north of Iceland that show the loaction of the earthquake swarm out in the ocean
The earthquake swarm far north of Iceland. Copyright of this image belongs to Icelandic Met Office.

Because of remote location of this earthquake swarm it is not possible to know what is going on there. The area is also under an ocean that is 2 to 4 km deep at this location. If anything happens it is not going to be noticed outside of being detected with seismometers.


If you want to support my work it is possible to do so with the donation button or regular donations option. Thanks for the support. 🙂

Currently total of eight craters are erupting in Fagradalsfjall mountain

This is a short update on the eruption in Fagradalsfjall mountain that is part of the Krýsuvík-Trölladyngja volcano system.

Yesterday (13-April-2021) the following thing happened around 09:00 UTC.

  • Four new crater started erupting. This did not reduce the lava output of the other craters that are erupting.
  • This means that now are total of eight craters erupting in the eruption in Fagradalsfjall mountain. The area is slowly being buried by fresh lava as the eruption goes on.
  • On Sunday 18-April-2021 it is going to be 1 month (30 days*) since the eruption in Fagradalsfjall mountain started. *This is a calendar thing, but using a website to calculate this correctly then this is the correct day using 30 day month calendar.
  • There continues to be high risk of new eruption fissures opening up without warning. Both north and south of the crater 1.
  • Gas output from the eruption has more than doubled in last few days. This is starting to create problem if wind blow the gas over populated areas.

I don’t have any more updates as is. If anything more happens I’ll update soon as I can. Since there is a risk of this eruption is going to last for a real long time, up to several years I might change my update schedule from what it is now. I’ll figure that out as the eruption continues.

News of the new craters

Drónamyndir: Fjórir nýir gígar (Rúv.is, video, map of the new craters)

Update 18:24 UTC

Morgunblaðið has released new video of the eruption craters.

Flögrað yfir nýju gíg­un­um (mbl.is)

Article updated at 18:25 UTC.

Deep earthquakes in Katla volcano

During the night of 11-April-2021 deep earthquakes took place in Katla volcano. Depth of this earthquakes was from 22,1 km to 24,5 km.

Earthquke activity in Katla volcano caldera rim and in east-west direction
Deep earthquake activity in Katla volcano. Copyright of this image belongs to Icelandic Met Office.

All of the earthquakes where small in magnitude and none of them did get to magnitude of Mw1,0. Earlier in the morning a swarm of smaller earthquakes took place at shallow depth but those are probably not connected to this deep earthquake activity. This earthquake activity has stopped and I am not expecting anything more to happen.

Update on Fagradalsfjall mountain eruption on 9-April-2021

This is a short article about the eruption in Fagradalsfjall mountain that is part of Krýsuvík-Trölladyngja volcano system.

This week has been busy and please read the older articles about what happened earlier in this week.

  • Lava output is now 50% more according to University of Iceland measurements compared to start of the eruption (19-March-2021). Gas output is also more then in start of the eruption. It has resulted in problems depending on wind direction.
  • There is a high risk that an eruption might start south of Geldingadalir valley eruption. There is also a high risk that new eruption is going to start north of the 5-April-2021 eruption.
  • There is no change in inflation in the area. It has slowed down but remains the same.
  • There continues to be low level earthquake activity along the dyke from Keili to Fagradalsfjall mountain.

Any change that is going to happen without warning and might not happen without any earthquake or little earthquake activity.

Next update is going to be on 16-April-2021 unless something major happens. This eruption is always changing and this weekend and next week might get interesting. If anything happens I am going to write new article soon as possible.

Update at 22:43 UTC

Icelandic Met Office released this map and press release (in Icelandic only) about the risk new fissures can open up both north and south the the current craters that are erupting. This page is updated regularly so if you are looking at this later than 9 to 10 April 2021 you might have to look for this information.

Map showing marked area that goes little south and north of the current erupting fissures in Fagradalsfjall. That area has been marked as dangerous by Icelandic Met Office. The map also shows the lava fields in purple.
The new area that has a risk of new fissures opening up without warning. Copyright of this image belongs to Icelandic Met Office.

The map shows the area that is now at risk of new fissures opening up without warning.

Update 10-April-2021 at 15:20 UTC

Around 03:14 UTC on 10-April-2021 fissure number 4 did open up between fissure number 2 (5-April-2021) and fissure number 3. The eruption from this crater doesn’t seem to be large but it did happen under a new lava that had flowed over that same area few days before from fissure 2. In fissure/crater 1 the amount of erupting lava did drop a little just before the new eruption.

I am noticing that it seems new fissures are opening up more frequently then before. This seems to have changed after opening up of fissure 3.

Timeline of fissure openings so far.

1st fissure 19-March-2021
2nd fissure opened 5-April-2021
3rd fissure opened 7-April-2021
4th fissure opened 10-April-2021

Time period between new fissures opening up currently seems to be 3 to 4 days. I suspect that this is going to change soon and it is possible that new fissure that opens up might get larger as the eruption goes on. There seems to be phase in this eruption that is happening in Fagradalsfjall mountain. I am not perfectly sure what that phase is now since I’ve never seen this before and I don’t have any data on this type of eruption behaviour from other volcanoes outside of Iceland. That I know of.

Video of the eruption fissure 4 opening up.

Nátt­úr­an er óút­reikn­an­leg og ófyr­ir­sjá­an­leg (mbl.is)

Article updated at 22:48 UTC.

Article updated at 15:39 UTC on 10-April-2021.
Article updated at 15:54 UTC on 10-April-2021.

Update on Fagradalsfjall mountain eruption on 8-April-2021

This is a short update on the eruption in Fagradalsfjall mountain in Krýsuvík-Trölladyngja volcano system.

Last 24 hours have been busy in the eruption. Here are highlights of what has happened best to my knowledge.

  • New fissure opened up and started erupting between the Geldingadalir eruption, second day of Easter eruption and the new eruption fissure is between the two.
  • The lava fields have now merged and are now one large lava field from Geldingadalir down to Meradalir valleys.
  • The eruption continues at the same slow rate as before even with several new vents erupting.
  • Morgunblaðið lost their first web camera to the lava flow (news can be found here in Icelandic). Icelandic Met Office had hardware close to the new lava flow. I don’t know if that hardware was saved from the lava flow but it was planned attempt to do so before it was lost to the lava.
  • The fissures might merge at future point and start erupting at one large fissure eruption. It is impossible to know if that is going to happen or when that might happen.
  • There has not been any deflation detected in the GPS data after the eruption started. That GPS data can be viewed here.
  • New fissures have been detected north of the crater that started erupting on 5-April-2021. Those fissure might start erupting without warning.
  • There is a risk of the eruption also going south-west and opening up fissures there. That has not yet happened but the possibility remains as a high risk possibility.

The situation is difficult to predict and new fissures can open up without warning. If nothing major happens then next update is going to be Friday 9-April-2021 on the eruption.

Update on the eruption in Fagradalsfjall mountain on 6-April-2021 (2nd update)

This is a short update and second update for 6-April-2021 for Fagradalsfjall mountain that is part of Krýsuvík-Trölladyngju volcano system.

  • During the night a new fissure was discovered between the new eruption and the old eruption. The fissure is about 150 meters long and there is hot air coming up from it.
  • There are reports of a new fissure north of the new eruption and land has been sinking down at that location. No other changes have been reported at the writing of this article.
  • The lava going down into Meradalir valley slows down once it is there because it cools down quickly once it is there. There is a lava river going down in the Meradalir valley and that lava is moving quickly.
  • It is now estimated that this is a start of a long volcano activity period on Reykjanes peninsula that is going to last for centuries with breaks of 10 to 20 years between active periods of 30 to 50 years.

The situation is currently changes often during the day and the night and the risk of a new eruptions starting without any warning is now extremely high.


Please remember to support my work with donations if you can. Thanks for the support. 🙂

Deep earthquake activity south-east of Katla volcano

Yesterday (5-April-2021) from 17:12 UTC until 17:36 UTC. This where all smaller earthquakes and according to Icelandic Met Office (Kristín on twitter) this area last had this earthquake swarm in this area eight years ago just south-east of Katla volcano.

Mýrdalsjökull glacier that contains Katla volcano. Just south east of Katla volcano a small cluster of  earthquake appeared at great depth in the crust
The earthquake activity south-east of Katla volcano. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity at this location has never resulted in an volcanic eruption in this location during historical times. The depth of this earthquakes was mostly around 19 km and magnitude was from Mw0,7 to Mw1,0.