Update on Sundhnúkagígar on 22. December 2023 at 20:49 UTC

This is a short update and information here might go outdated quickly and without warning.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.

Red dots along the rift valley and orange dots from the earlier earthquakes today.
Earthquake activity along the rift valley today. This is a lot of earthquake activity. Copyright of this image belongs to Icelandic Met Office.

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.

Update on Sundhnúkagígar activity on 21. December 2023 at 18:47 UTC

This is a short article, written on 21. December 2023 at 18:47 UTC. Information here might go outdated quickly and without warning.

The eruption that started on 18. December 2023 at 22:17 UTC is over, best I can see. This was large eruption, but a short one. Total lava flow covered an area of 3,7 km2 (square kilometre). Most of the eruption happened in the first 24 – 48 hours of the eruption. There are early indicators that inflation has resumed in Svartsengi volcano, if it inflates at the same rate as before this eruption it is only going to take 8 to 10 days until next eruption. This is a big question since there’s a lot of magma in Svartsengi volcano and that magma can move towards the surface, even if the inflation doesn’t happen and can result in a larger eruption. If that happens is a wait and see situation.

Videos from the eruption areas show a lot of degaussing in the eruption fissure. This is interesting and I am not sure why that is. There’s a chance a lot of magma is in the dyke that is just releasing gas into the air without having the energy to erupt. There’s a small chance that a new eruption might happen in the same location. If that happens is impossible to know.

Red dots and yellow dots in the rift zone valley where the eruption just ended. Time on image is 21. Des. 2023 at 19:15 UTC.
Earthquake activity along the rift valley. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity is interesting, it started yesterday (20. December 2023). This follows the same pattern as the earthquake activity before the start of the eruption on 18. December. If that is what is happening remains a wait and see situation for now.

This is the last update unless something happens in this area. Based on current information, that is what is going to happen, the question is just when.

Update for Sundhnúkagígar eruption on 20. December 2023 at 18:29 UTC

This is a short update and information here might go outdated quickly and without warning.

This eruption is a short one and that’s how eruptions in Iceland are normally. This eruption might end by Friday to Monday, depending on what happens.

  • The flow from the craters that are erupting is around 10m3/sec. This is low compared to the start of the eruption on Monday 18. December 2023 and suggest that this eruption is going to end soon.
  • GPS data shows that Svartsengi volcano has only lowered around 80mm since Monday. This means there’s a lot of lava in Svartsengi for new eruptions to happen without much warning.
  • Earthquake activity along the fault valley has resumed, after stopping soon after the main eruption took place. This is interesting and I am unclear what this means at the writing of this article.
  • Icelandic Met Office is reporting that the eruption, even is small, is stable at the writing of this article. This can change without warning.
  • The lava field is now, according to best measurements around 3,7 km2 (square kilometres).
  • According to University of Iceland Earth science department, the chemical makeup of the lava shows that its more evolved in part than the lava in Fagradalsfjall volcano. This can be read here (new link, now in English). This means that this magma stopped on its way to the surface and cooled a little and changed chemical makeup before erupting.
  • This new lava is different than the lava that erupted 2400 years ago at the same location. Why that is I don’t know. It is going to take few years to maybe get an answer to this question when the experts have done their research and published their science papers.
Earthquake activity along the rift valley in Svartsengi volcano shown by a green stars, red and orange dots showing smaller earthquakes.
Earthquake activity along the rift valley. Copyright of this image belongs to Icelandic Met Office.

It is interesting to see that Þorbjörn mountain continues to get lower, based on GPS data from today (20. December 2023). Icelandic Met Office has released new danger map and that can be found here in English on Icelandic Met Office website.

This is all the information I know of today (20. December 2023). Next article should be tomorrow (21. December), unless something happens then I’ll try and write article soon as I can.

Update on the eruption in Sundhnúkagígar on 19. December 2023 at 21:46 UTC

This is a short update and information here might go outdated quickly. This article is written on 19. December 2023 at 21:46 UTC.

I am trying to collect and read all the information I can find. I don’t have access to everything my self, so I am depended on news and reports from Icelandic Met Office and others on what is happening in this eruptions. This is not unusual and has always been like this.

  • The eruption is now in 2 to 4 vents. I am little unclear at the writing of this article now many are erupting.
  • The new dyke seems to go into the dyke from 10. November. This can result in reactivation of the dyke from 10. November and result in an eruption along it, all 15 km at random location.
  • Current flow seems be around 50m3/sec at the writing of this article. I’ve been hearing that highest flow yesterday (18. December) was around 800m3/sec, but that number is for me unconfirmed. It dropped to 100 – 500m3/sec soon after the eruption started.
  • Early GPS data from today seems to suggest that Svartsengi volcano has lowered about 50mm since the start of the eruption. I am waiting for new GPS data on Icelandic Met Office website. That data hopefully shows up tomorrow (20. December).

There’s a lot of uncertain things that can happen with this eruption at the moment. Since there’s a lot of lava in Svartsengi volcano that has not erupted so far. New inflow of lava from the deep mantle is also a possibility and those can happen without warning as the pressure drops in Svartsengi volcano sill (or magma chamber).

I’ll post next update tomorrow (20. December 2023) or sooner if anything happens.

Update on the eruption at Sundhnúkagíga on 19. December 2023 at 16:10 UTC

This article is short and is written at 16:10 UTC on 19. December 2023. Information here can go outdated quickly and without warning.

There has been a reduction in the eruption since it started at 22:17 UTC on 18. December 2023. This was to be expected. Since the eruption seems to be coming from a small sill in Svartsengi volcano, rather than a large magma chamber.

  • The eruption is now limited to three to four eruption vents. The largest one is where the eruption started. Crater building is ongoing.
  • The lava is flowing towards Fagradalsfjall volcano (mountain) at the writing of this article. This area is empty, outside of the the parking lots south of Fagradalsfjall. They are not at risk for now.
  • The problem with eruptions of this type is that they can grow again in size if different sill breaks and starts flowing into the established flow channels that magma is now flowing and creating the eruption. If that happens is impossible to know. This can also result in a eruption that goes on for a long time. If that happens, an lava might end up reaching far away areas.
  • It is going to take few days for GPS data to show what sill is deflating in Svartsengi volcano and what is going on in the crust in Svartsengi volcano.
  • Weather might be a problem for next few days on Reykjanes peninsula.
  • This area is not to hike around on. Its dangerous and the weather makes difficult walk extremely difficult.  Just watch the online web cameras.
  • The lava field is large and it creates its own strong wind as the lava warms up the air around it. That can be difficult to deal with in the snow for anyone close the the eruption.

The dyke is longer than the part that erupted according to the news and measurements. The dyke is more south and it ends just 1,5 km north of Grindavík town. That area can erupt without warning if pressure starts to build up in that part of the dyke. That same goes for the north part of the dyke, how far more north the dyke is I don’t know.

I’ll post next update when I have more information what is going on or sooner if anything happens.

Update on the eruption in Sundhnúkagíga on 19. December 2023

This article is written on 19. December 2023 at 02:35 UTC. Information in this article can go outdated quickly and without warning.

  • The fissure is at last measurement around 4000 meters long (4 km) according to the news.
  • The volcano that is erupting is Svartsengi volcano. On some maps this is shown as Reykjanes volcano.
  • This is the largest eruption on the Reykjanes peninsula  so far.
  • The lava flow is mostly to the east, a way from infrastructure and roads. This is mostly, but can change without warning.
  • There’s a lot of gas pollution from this eruption. This gas is dangerous to people and animals.
  • The lava flow from the fissure is around 100m3/sec to 200m3/sec.
  • The fissure has started to form crates. This is going to continue to create craters as the eruption goes on.
  • There’s a ongoing risk that the eruption fissure might extend to the south towards Grindavík. If that actually happens is impossible to know.

I am going to write next update sometimes later today (19. December 2023) when I have new information and more is known about this eruption.

Eruption started close to Hagafell mountain (Update for Grindavík on 18. December 2023 at 23:17 UTC)

This is a short update. Information here is going to get outdated quickly.

An earthquake swarm started at 21:05 UTC in the dyke area that formed on 10. November 2023. This earthquake swarm is ongoing and seems to be connected to when the eruption fissure expands south towards Grindavík town. The eruption started at 22:17 UTC. There’s a lot of dangerous gas pollution from this eruption. Do not get close to this eruption. This is not a small tourist friendly eruption.

A lot of red dots showing the earthquake activity in the dyke and Svartsengi just before the eruption.
The earthquake activity in the dyke. Copyright of this image belongs to Icelandic Met Office.

I’ll post new article when I know more in next few hours.

Earthquake swarm in Tjörnes Fracture Zone

During the night and into the morning of 18. December 2023 an earthquake swarm took place in Tjörnes Fracture Zone just south east of Grímsey island. Largest earthquake in this swarm had a magnitude of Mw3,4 at 08:06 UTC and was felt in Húsavík, Akureyri and Grímsey according to the news. Other earthquakes in this swarm where smaller in magnitude.

Green star just south-east of Grímsey island. With few dots that show the area of the earthquake activity in the Tjörnes Fracture Zone.
Earthquake activity in Tjörnes Fracture Zone. Copyright of this image belongs to Icelandic Met Office.

Earthquake activity in this area is common and larger earthquakes are frequent. Earthquake swarms happen regularly. This earthquake swarm seems to have ended.

Inflation in Svartsengi volcano reaches 10. November levels

This information is unclear, but this is the best information I have at the writing of this article.

It seems that Svartsengi volcano has reached close or the same level as 10. November levels. There has been a slight shift where the inflation has been happening. It seems to have moved slight closer towards Þorbjörn mountain, that also means the main inflation is happening closer to Sundhnúkar and Sundhnúkargígar and Sýrlingafell mountain. This strongly suggest that magma is building up in this area because of the ongoing weakness in the crust in this area. This also strongly suggests that when the magma in this sill goes next on the move, it is going to go up towards Sundhnúkar and Sundhnúkagígar area and into the dyke that formed on 10. November 2023. That dyke has filled up all available space created by the rift valley, next dyke is more likely to start an eruption than the dyke created on 10. November.

There’s no earthquake activity in Svartsengi volcano at the moment, until that happen, the volcano is quiet at the writing of this article. It is more than likely that an strong earthquake swarm is going to start in Svartsengi volcano and close to Sundhnúkar and Sundhnúkagígar once the magma gets moving again. Inflation in a volcano does not always result in increased earthquake activity, since this depends slightly on what has been happening and how the crust is in that volcano at that time when activity is ongoing. It is impossible to know when next activity starts in Svartsengi volcano, but there is a chance that the magma that has flowed into the sill needs a time to change before it moves again. That can take time, how long is difficult to know, but this might be from six months and up to two years at most. This depends on the magma flowing in, gas content and such, so it can happen both slower and faster than earlier inflow of magma into the sill in Svartsengi volcano.

At the writing of this article. Everything is quiet in Svartsengi volcano.

Earthquake swarm close to Eldeyjarboða on Reykjanes ridge

Today (9. December 2023) at 05:55 UTC to 06:44 UTC an earthquake swarm took place deep on the Reykjanes ridge. This earthquake swarm is far from the coast so smaller earthquakes where not detected by Icelandic Met Office. Largest earthquake in this swarm had a magnitude of Mw3,8.

Green star and yellow dots far from the coast of Reykjanes peninsula. This is far out in the ocean.
Earthquake activity deep on Reykjanes ridge. Copyright of this image belongs to Icelandic Met Office.

This is in a volcano, its unclear if this is in the volcano Eldeyjarboði or a different unnamed volcano. This earthquake swarm seems to have stopped by now.