Update on the Sundhnúka / Kálffellsheiði / Reykjanes volcano / Fagradalsfjall volcano / Grindavík dyke intrusion

This is a short update. Information here might go outdated quickly and without warning. This update is written on 11. November at 22:42 UTC.

  • The dyke is 15 km long at the writing of this article. It might be extending both north-east and south-west. Earthquake activity remains heavy but the magnitudes have dropped for now.
  • The inflation in the area is around 120 cm or more since start of this yesterday (10. November 2023).
  • The dyke now extends into the ocean and the part in the ocean is around 3 to 5 km. At shallow depth, this is going to result in explosive eruption for the first few hours to days.
  • The magma is now at depth of 800 meters, where it is the most shallow. That might not result in a eruption at that location.
  • Eruption is going to start without warning. Since Icelandic Met Office has issued that they can’t see the harmonic tremor start because of heavy earthquake activity in the dyke.
  • There is now a major risk of large earthquakes both east and west of the dyke because of all the displacement resulting from him. Those might happen days or even weeks in the future.
  • Icelandic Road Administration published pictures on Facebook here, showing the damage from the displacement and from the earthquakes. The ground is falling apart and opening up.

 

Image of the dyke in direct 15 km line from north-east to south-east.
The dyke location. Copyright of this image belongs to Icelandic Met Office.

It is difficult to know what happens next and this eruption is not going to be small or tourist friendly.

Hundreds of green stars showing earthquakes larger than magnitude 3,0 next to Grindavík and nearby area.
The insane amount of earthquake activity next to Grindavík town in last 48 hours. Copyright of this image belongs to Icelandic Met Office.

I’ll post updates once I know more.

Dyke has formed or is forming under Grindavík town, mandatory evacuation ordered

This is a short article. Its going to outdated quickly.

  • Dyke has or is forming under Grindavík town. This dyke starts at Sundahnjúkar in north-east of Grindavík town and is going to down to Grindavík. This is at the moment around 4 to 7 km long dyke. It might get longer and reach the ocean.
  • There’s a mandatory evacuation order in place. Everyone in Grindavík town has two hours (from around 23:00 UTC) to leave the town. Many people had already left because of the heavy earthquake activity today (10. November 2023).
  • Earthquake activity remains heavy, but is lower than it was at around 17:00 to 19:00 UTC. This might change again without warning.
  • GPS data suggests this is more magma than in all of last three eruptions combined.
  • This magma might be from Fagradalsfjall volcano. This is currently only an idea. That means the magma in Reykjanes volcano has not started to move to the surface. That might also happen without warning at any time, since that inflation continues.

I’ll post more information when I got them. The situation is unclear and there’s a lot of wrong information out there so check your sources.

Icelandic Met Office confirms magma is rising to the surface

Icelandic Met Office has confirmed that magma is now rising to the surface in the area of Sundahnjúkar crater row. This does not seems to be connected to Svartsengi magma (Reykjanes volcano) dyke intrusion. How much magma and what volcano it is connected is unclear at the writing of this article. This might not be connected to Fagradalsfjall volcano also. If that is the case, it means this either a new unknown volcano at this location or rift eruption not connected to any volcano. It is going to take a while to get an answer to that question once the eruption has started.

There is a change in the earthquake activity as the magma goes up the surface. This happens because the layer of crust that the magma goes through does not all have the same density up the surface level. Softer rocks result in fewer earthquakes and harder rock results in higher earthquake activity. It is mostly not possible to know what type of rock the magma is going through. But this shows in the earthquake activity.

I’ll post more updates once I have any new information.

Danger level declared for Reykjanes volcano and Grindavík town

This is a super short update. Since there’s too much happening at the writing of this article for me to write anything useful about current situation.

  • There’s a super dense earthquake swarm happening north-west of Grindavík town. There’s also an earthquake swarm north-east of Grindavík town.
  • Almannavarnir have declared danger level for Reykjanes volcano and Grindavík town.
  • There’s a lot of earthquakes with strong magnitudes. Useful list is not possible at the writing of this article.
Dense earthquake swarm on WinSDR plot. Earthquakes happening every 10 second.
Dense earthquake activity at distance of 187 km.

This is what I am recording at the distance of 187 km from the source at Reykjanes peninsula. This is the most dense earthquake activity I’ve ever seen.

I’ll post update when I know anything useful.

Strong earthquake swarm in Reykjanes volcano

This is a short article. It might get outdated quickly.

Around midnight of 9. November 2023 an strong earthquake started close to Þorbjörn mountain, in the same area that has been having an earthquake and dyke intrusion since 25. October 2023. At the writing of this article, the largest earthquake had a magnitude of Mw5,0 and with a lot of smaller earthquakes taking place.

A lot of green stars and red dots close to Grindavík town on the Reykjanes peninsula in the volcano Reykjanes.
Strong earthquake activity in Reykjanes volcano. Copyright of this image belongs to Icelandic Met Office.

It is unclear if this earthquake activity is the start of the eruption or just normal inflation related earthquake activity. The magma is still at depth of 5 km. If it has started to move upwards trough the crust, it is going to take several hours to reach the surface. That means nothing might happen on the surface until late tomorrow or on 10. November at the earliest. Depending on how quickly the magma goes up through the crust.

I’ll post updates tomorrow if anything more happens.

Update on Reykjanes volcano activity

This is a short update and this information can go out of date quickly and without warning.

  • Earthquake activity continues in Svartsengi and close to Þorbjörn mountain. This earthquake activity is either tension earthquakes because of the dyke on either side (north-east and south-west) or in the dyke it self.
  • Inflation in Svartsengi and nearby area is extremely high and has been increasing much as 10mm a day in last few days.
  • There has been magma building up in the crust in the Reykjanes volcano since at least year 2020. It might have started few years earlier at more depth, but that is unclear.
  • There’s a risk of large eruption in this area, that might go on for few months in the worst case.
  • Largest earthquakes so far have had the magnitude of Mw4,7. Larger earthquakes remain a possibility.
  • It is impossible to know when a eruption starts or if it starts. But the likelihood of an eruption is extremely high.
  • Morgunblaðið reported that ground heat has been seen on thermal cameras. The news can be found about this here in Icelandic. There’s a YouTube video of this in both Icelandic and English (with more footage).

I’ll post new information about what is going on when it happens. As is, the situation does not change a lot from one day to another so I don’t have a lot to report on.

Magma movement close to Þorbjörn mountain this morning

Today (31. October 2023) at around 08:00 UTC an magma movement was detected by Icelandic Met Office. This started an earthquake swarm that had a largest earthquake with magnitude of Mw3,7. The magma seems to be at depth of 1,5 km where it is the shallowest. Few days ago, that magma was at depth of 5 to 8 km. This change is rather quick movement of magma, that suggests higher pressure compared the magma that erupted in Fagradalsfjall volcano. This might result in a larger eruption when it happens. The inflation at Fagradalsfjall volcano, south part of it has not lowered. The only thing that has happened there is that earthquake activity has dropped to almost nothing. Earthquake activity has moved to western part of Fagradalsfjall volcano. Eruption also happening in Fagradalsfjall volcano should not be ruled out, but the events close to Þorbjörn mountain might delay the progress of that magma.

Red dots and green stars north of Grindavík town, close to Þorbjörn mountain. There's also red dots west of Þorbjörn mountain and Grindavík town. Blue dots close to Reykjanestá on this map. Time on map is 31. Okt. 23 at 16:55 UTC.
Earthquake activity because of magma movements in Reykjanes volcano. Copyright of this image belongs to Icelandic Met Office.

It is difficult to know what is going to happen next. But an eruption is highly likely, when and where is almost impossible to know even if GPS data gives good clues on where it might happen. This situation is complex and it is uncertain what is going to happen next with this activity in Reykjanes volcano and Fagradalsfjall volcano.

I’ll post information soon as I know something. A list of web cameras of Icelandic volcanoes can be found on the YouTube page that I set up a while ago.

Reykjanes volcano placed on Yellow warning level

The Reykjanes volcano has been placed on yellow warning level. This is because of sudden inflation that is now taking place north-west of Þorbjörn mountain. In slightly less than 24 hours the inflation did reach 30mm. This is the fifth time (as reported by Morgunblaðið) that inflation has happened in this area since the year 2020. This inflation now is a lot faster than earlier when this has happened.

Yellow triangle on the Reykjanes volcano on the Reykjanes peninsula. Other triangles, showing other volcanoes in Iceland are green.
The alert status for Reykjanes volcano is now yellow. Copyright of this image belongs to Icelandic Met Office.

This inflation in the Reykjanes volcano has the risk of creating stronger earthquakes in new locations on the Reykjanes peninsula and on the Reykjanes ridge in next few days to weeks. There is a ongoing inflation in Fagradalsfjall volcano and that has not stopped or slowed down since it started on 25. October 2023. It is not possible to know when or if an eruption in going to start in Reykjanes volcano, but how quickly this inflation is happening suggests that might happen. The location is not that good, if it erupts where the inflation is happening. The blue lagoon is nearby along with power plant and hot water energy plant in this area. Eruption in this location can result in major damage to infrastructure in this area.

Only thing that can be done now is to wait and monitor what is happening in this area.

New earthquake swarm in Fagradalsfjall volcano and in Þorbjörn mountain (Reykjanes volcano)

This article is going to get outdated quickly.

Current activity is also complicated and might not behave in the same way as earlier eruptions did. Largest earthquakes at writing of this article have had magnitude of Mw3,5 and Mw4,5. Larger earthquakes can be expected without warning. There have been around 1000 smaller earthquakes at the writing of this article.

Green stars close to Þorbjörn mountain and a lot of red dots in south part of Fagradalsfjall volcano. There is also green to west of Þorbjörn mountain.
Earthquake activity in Fagradalsfjall volcano and Þorbjörn mountain. Copyright of this image belongs to Icelandic Met Office.

There is a good chance this events are not going to behave the same way as happened in earlier eruptions, because the location is little bit difference and that can result in a lot of change on what happens when magma pushes it self up through the crust. The earthquake activity close to Þorbjörn might be a mixed earthquake activity of tension breaking earthquakes and magma pushing it self up. GPS data doesn’t show any inflation close to Þorbjörn mountain at the writing of this article.

Earthquake activity is increasing in south part of Fagradalsfjall volcano, this is area in Nátthagi, Nátthagakriki and other nearby area. There is a dyke intrusion in that area and has been a while. That dyke intrusion might be about to erupt. There is a lot of uncertainty going on at the writing of this article. There is also a pattern of high and low in the earthquake activity, this has been the pattern in the earthquake activity before the earlier eruptions.

I’ll write updates about this activity as needed. It might take a while, since I always try to figure out what is going on before an article is written.

Earthquake swarm in Reykjanes volcano (ongoing)

Today (27. September 2023) an earthquake swarm took place in Reykjanes volcano on Reykjanes peninsula. This earthquake swarm is ongoing at the writing of this article. At the writing of this article, the largest earthquake had a magnitude of Mw3,3 and the second largest earthquake had a magnitude of Mw3,1.

Green star on the Reykjanes peninsula in the Reykjanes volcano, there's also a green star at Reykjanestá that is next to the ocean. A lot of orange and red dots at this same location.
Earthquake activity in Reykjanes volcano. Copyright of this image belongs to Icelandic Met Office.

The source of this earthquake swarm seems to be magma intrusion into this part of Reykjanes volcano. I don’t know if this is going to result in a eruption, this earthquake activity seems to be too low for that to happen. That might change without warning, as sometimes happens with volcanoes. This is at least highly active time period now and what is going to happen is unclear.