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 Information in this article can go outdated quickly and without warning.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 Information here is going to get outdated quickly.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.

Earthquake swarm east of Grímsey island

Today (9. December 2023) an earthquake swarm took place east of Grímsey island, it started at 11:09 UTC and ended around 12:19 UTC. This was a small earthquake swarm and largest earthquake had a magnitude of Mw3,0.

Green star and red dots east of Grímsey island from the small earthquake swarm. This is out in the ocean.
Earthquake swarm east of Grímsey island. Copyright of this image belongs to Icelandic Met Office.

This area of Tjörnes Fracture Zone has frequent earthquakes and earthquake swarm activity. Large earthquake swarms happen in this area every few years. Time between them is different. If that is the case now is impossible to know.

Update for Grindavík on 8. December 2023

This is a short article about the situation in Grindavík. Information here might go outdated quickly without warning.

Sorry for the late update. I was updating my computer and its been more of a problem than I expected. Since I build my own computers, rather than buying already assembled computer.

Overview of the situation in Grindavík

Inflow into the dyke seems to have stopped one to two days ago. This means that it has started to cool down, since no inflow of fresh magma means it starts to form into rock. This is going to take years and in some areas decades cool all the way through. This also means that the rift valley is no longer moving as much as it was doing and in some areas has stopped completely. There is a crust instability in and around Grindavík town because of the rift valley, but this instability is now lower compared to first few days after 10. November. This might continue for years, even after all eruption activity stops few hundred years into the future.

Inflation has now reached almost the same level as 10. November, with only 50mm to go until the same level is reached. This inflation seems to be creating cracks in the ground around Svartsengi power plant. But the news was not clear on exact area of the formation of those cracks in the ground. Svartsengi, Grindavík and the area around the dyke continues to be a danger zone as defined by Icelandic Met Office.

This image shows the four danger zones around Grindavík. With zone 1 being in Svartsengi, Zone two to be north of Grindavík and zone three to be south east of Svartsengi and north of Grindavík. Zone four is Grindavík. Zone three is the most dangerous one.
The danger zones in Grindavík. Copyright of this image belongs to Icelandic Met Office.

The original image can be found here on Icelandic Met Office website.

This is not over and it is impossible to know when next sequence of events starts in Svartsengi and there is going to be little to no warning when it starts next. Icelandic Met Office has sad that at most there is going to be a two hour warning before an eruption starts, but it might even be shorter time. Making staying in Grindavík and nearby area all hours of the day a dangerous thing to do.

This is the last update until something happens in Grindavík.

Update on Grindavík for 4. December 2023

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

There has not a lot been happening in last few days. Here is a overview for the last few days.

  • Inflation continues in Svartsengi. Over the 90 day GPS data period. The inflation has reached the zero line. That means the inflation is now at the same level as it was before 25. October 2023. It still has about 100mm to go before it reaches 10. November levels and the sill broke and the magma dyke happened. But it is important that the GPS data from 2020 shows that Svartsengi lowered to 140mm below the January 2020 starting point with the GPS data.
  • The GPS data from January 2020 for Svartsengi show that total inflation in the area is around 230 to 250mm. This information can be viewed here (this is a none https link, so it might require an exception in Google Chrome or just use Mozilla Firefox). There’s a lot of GPS data on this site. Some of it show short term GPS data that are from last 12 hours daily update. Looking for the correct data image might take some time.
  • Inflation might need to reach 10. November levels before anything happens again. The dyke even on 10. November seems to have changed how things happen in Svartsengi so it is impossible to be sure what happens next.
  • While the magma collecting phase is ongoing. Things are going to be quiet with the earthquake activity in this area.
  • The rift valley, best I can see, continues to change and sink and rise. Resulting in ongoing damage to Grindavík town.
  • There’s less news about this at currently. That gives me less information on what is going on.

Next update should be by Friday 8. December, unless something happens.

Update on Grindavík for 30. November 2023

Information here might go outdated quickly and without warning. This article is written on 30. November 2023 at 23:44 UTC.

There isn’t much change happening at the moment. People are now allowed to be in Grindavík between 07:00 to 19:00 I think the time frame is. Earthquake activity is at minimum currently.

Daily update

  • Deepest hole that has been discovered so far is 25,7 meters deep. It is deeper, but at 25 meters the ground water level starts and hides the actual depth of this crack. Rúv news about this found here with pictures and videos in Icelandic.
  • New cracks and the ground continues to sink and move in most of areas of Grindavík. This is resulting in more damage to houses and streets in Grindavík town.
  • The harbour area in Grindavík has lowered 30 cm to 40 cm. That was the news two days ago. I think the harbour area continues to sink. This might be a signs of future problems if the ocean manages to flow into this area.
  • Svartsengi volcano continues to inflate at the rate from 10mm to 40mm a day. The last 24 hour inflation was around 40mm. Earlier the inflation had just been 10mm a day. Suggesting a increased flow of magma into Svartsengi volcano.

Something might start to happen around or after 9. December when the sill in Svartsengi is expected to reach the same pressure it was on 10. November when it broke the first time and emptied and created the dyke that formed under Grindavík and the nearby area.

Update on Grindavík for 28. November 2023

This is a short update for Grindavík and nearby area on 28. November 2023. This article is written at 23:22 UTC. This is a short update and information here can go outdated quickly and without warning.

Last few days have been quiet with little or few earthquakes. There have been earthquake swarm activity at times, suggesting that magma is trying to push at faster rate into the crust at Sundhnúkagígar and Sundhnúkar mountain. I don’t know what the current rate of magma inflow is.

Daily information

  • Magma continues to flow into the dyke. I don’t know how fast that rate is.
  • The dyke is wider than originally thought. This means it cools down more slowly. The dyke is widest around Sundhnúkar and Sundhnúkargígar area.
  • Eruption can start without warning in Sundhnúkar or Sundhnúkargígar and that area.
  • New cracks continue to form in Grindavík, along with sink holes and other issues that is creating.
  • Inflation at Svartsengi is around 10mm/day and up to 40mm/day. Currently, the inflation has slowed down to 10mm/day. This can change without warning.
  • Top of Keilir mountain has moved according to the news. I don’t know how much. But this is a displacement.
  • Rocks with the size of mobile homes have moved and rolled down from mountains.
  • Cracks are forming in a wide area around the dyke according to the news. Making it dangerous to travel in the area around Grindavík because of this new cracks in the ground.

The event in Grindavík and nearby area is not over. It is ongoing, this is just a quiet time period that is currently happening. This quiet time period is going to happen frequently in the Reykjanes volcano system. I don’t know why that is the case, this is the reality of what is going on.

Article updated at 23:56. I forgot to add few things.