Category: Harmonic tremors

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Update on the eruption in Sundhnúkagígar (Svartsengi volcano) on 17. March 2024 at 18:28 UTC

This is a short update because I don’t expect a lot to happen in this eruption.

Here are the main details as they are known on 17. March 2024 at 18:28 UTC. This is the best information I have at current time.

  • The eruption has gotten smaller since it started yesterday (16. March 2024 at 20:23 UTC). The fissure is now only erupting in three to four locations.
  • The lava field did reach the barriers that are protecting Grindavík town.
  • This eruption is not slowing down as quickly as earlier eruptions.
  • Harmonic tremor is mostly consistent but is lower than yesterday when the eruption started.
  • The eruption fissure seems to be around 800 meters to 1 km long.
  • There’s a ongoing risk of new fissures opening.
  • Lava flow seems to have slowed down, but that might because it might be collecting in large lava ponds that break and then the lava rushes forward at great speed.
  • Suðurstrandarvegur is at risk of getting buried by a lava flow. If that happens, the risk of the lava reaching the ocean increases, since from the road the distance is only around 500 meters.
  • There’s no signs of this eruption ending on the web cameras.
  • Craters have started forming in the active parts of the fissure.

If anything more happens I’ll post update soon as I can. Normally, an eruption from Svartsengi volcano only last around 1 day. If this eruption goes longer, then next update should be tomorrow or sooner if anything important happens.

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Dyke intrusion into Sundhnúkagígar from Svartsengi volcano yesterday (02. March 2024)

Yesterday (02. March 2024) at 15:57 UTC an earthquake swarm started in Sundhnúkagígar, all earthquakes where small in magnitude and around 150 where recorded. This earthquake swarm was as sign of a dyke intrusion that was starting into Sundhnúkagígar. It did not result in a eruption, but might be a sign of where next eruption is going to happen, when it happens. The dyke intrusion ended around 17:57 UTC.

This is a bit early, but it seems that this dyke intrusion moved or changed the rift valley it happened in. This rift valley was created in the dyke intrusion on 10. November 2023 (Icelandic Met Office has a image of it here). It might also have moved the rift valley that was created on 14. January 2024 (image of that rift valley can be found here, its marked with a blue colour). This rift valley situation is making the geology in this area extremely complex and volatile. Since the crust, the top layer is extremely fractured in areas of the rift valley and that makes it easy for the magma to find a path to the surface.

It is impossible to know when next eruption is going to happen. But it is my own estimated that next eruption might happen between 3. March to 5. March. I might be wrong on this, that’s always an possibility.

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Update on the eruption at Sundhnúkagígar at 22:41 UTC on 8. February 2024

This is a short update on the eruption at Sundhnúkagígar.

  • Four hour GPS data shows that inflation has already started in Svartsengi volcano, that is currently erupting. This inflation seems to have started soon as the eruption started to get lower around 13:00 UTC.
  • The lava flow damaged the hot water pipe from Svartsengi power plant and now around 26.000 people on the Reykjanes peninsula are without hot water. There is also some damage to the power infrastructure, but that is minimal and that power has been restored on the power lines that are next to the lava flow. The situation on the cold water is unclear, but it was at risk of damage.
  • This eruption was larger compared to the eruptions on 18. December 2023 and on 14. January 2024.
  • Small ash cloud formed today and the reason for that, according to experts in the news. Was that the eruption in part of the fissured ended so suddenly with a pressure drop that the fissure walls collapsed, allow ground to get in touch with lava and then ground water started to flow on the lava. Resulting in two clouds, one dark and a steam cloud. This was large for an about hour or two. Steam cloud was ongoing at writing of this article, but darkness prevents me from seeing if this has stopped. It is likely though.
  • The eruption is ongoing in two to three craters at the writing of this article.
  • It is expected, based on current rate of how much the eruption is slowing down that it is going to end tomorrow, 9. February or on 10. February.
  • Next eruption is going to be in March around 6th to 18th March if current pattern holds for Svartsengi volcano. There’s nothing to rule out that a new eruption might happen sooner. It is impossible to know what happens next in Svartsengi volcano eruptions.

If anything more happens. I’ll post update soon as I can.

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Update on the eruption at Hagafell on 15. January 2024 at 01:14 UTC

This is a short update about ongoing eruption that can change without warning and information here can go out of date quickly.

  • Eruption started close to Hagafell mountain at 07:58 UTC on 14. January 2024. Two fissures opened up.
  • The largest fissure was at its maximum length around 900 meters. The second smaller fissure is around 100 to 200 meters long.
  • The second fissure is almost inside Grindavík town and has lava flowing into the town.
  • Lava flow has destroyed two to three houses at the writing of this article.
  • In the last few hours, the harmonic tremor has dropped. This suggest that the strength of the eruption is getting lower.
  • There’s no power, cold water or hot water in Grindavík town. Lava has destroyed the cold water, hot water and power lines that go into Grindavík town. Repairs are going to take months if Grindavík town is found save to live in after few months.
  • New fissures and displacement happened during the dyke intrusion phase of this eruption. Some areas of Grindavík town moved up to two meters in either direction according to Icelandic Met Office. At this time, accurate measurements have not been done because how unsafe the area is.
  • The eruption is happening alongside the rift valley and not in it. I am not sure why that is.

This is all I have for now. Next update should be on 16. January unless something major happens in this eruption.

Rúv has web cameras on their YouTube channel and same does mbl.is and Vísir news website.

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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.

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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.

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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.

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Update on Grindavík for Wednesday 22. November 2023

This is a short update. Information there might go outdated quickly and without warning. This article is written on Wednesday 22. November 2023 at 21:32 UTC.

There’s little news to report at this moment. Mostly because of bad weather. The progress of the dyke has also stalled from earlier, or this might be it for now. It is difficult be sure currently.

Risk map of Grindavík and the total of 15 km in both directions. The red zone, danger zone b has been withdrawn to north of Grindavík and now its just a small line north of the town and up north along the dyke. The most dangerous risk zone is north of the town.
The risk zone around Grindavík. Copyright of this image belongs to Icelandic Met Office.

The inflation at Svartsengi (upwards movement) stopped in the last 24 hours. This either means this series of events is stopping for now or something major is about to happen. I am not sure. Risk of this being a error are small, but this might be interference from weather (rain, snow).

The air code for Reykjanes volcano has been downgraded to yellow.

Aviation colour code for volcanoes in Iceland. All are green except Reykjanes volcano that is now yellow.
The aviation colour code of volcanoes in Iceland. Copyright of this image belongs to Icelandic Met Office.

The situation in Grindavík and in Sundhnúkagígar and the nearby area can still change without much warning. Since the ground is very fractured there and is not going to be much resistance to any magma movements in the near future.

If anything more happens. I’ll update soon as I can.

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Update on Grindavík 17. November 2023

This is a short update on the situation in Grindavík on 17. November 2023. Information here can go outdated quickly and without warning.

Daily updates

  • Grindavík town continues to sink as the rift valley continues to move. The speed of sinking has slowed a little according to the news today.
  • Earthquake activity has slowed down in last few hours (this is written around 22:51 UTC). What that means is unclear.
  • Some houses in Grindavík town have been completely destroyed. Iceland has a natural disaster fund for this type of situation and that is going to cover the owners loss according to the news.

General update

It took me a week. But it seems that this dyke intrusion under Grindavík town is because of the magma sill (dyke) under Svartsengi. That area has inflated around 110mm in a week. That is a inflation of 15mm/day based on my best calculations. That is a lot of inflation, since before 10. November the inflow of magma into Svartsengi was at most 8m3/sec according to measurements of Icelandic Met Office.

The sill in Svartsengi created a lateral dyke in Sundhnúkar and nearby areas. When the pressure in the sill is high enough again it is going to push the magma into the dyke at Sundhnúkar again with the same force as it did before. How long that takes I don’t know. Last time this was from 25. October to 10. November. That’s seventeen days, but there was a lot of deeper sills in Svartsengi and its impossible to know much, if anything flowed form them into the dyke. This is my personal view, it might be wrong. But this is what I am reading from the data.

Risk of the eruption remains high because there’s a ongoing inflation at Svartsengi. When a eruption starts is impossible to know.

If anything happens. I’ll post update soon as I can.

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Update on Grindavík on 16. November 2023

This is a short update on what is happening in Grindavík on 16. November 2023. Information here can go outdated quickly and without warning.

The situation is mostly the same as yesterday (15. November 2023), but few things have happened and that is enough for me to publish this article.

  • Sulfur dioxide has been detected in a drilling hole in Svartsengi. This drilling hole is such that it end point is close to Hagafell mountain  east to Svartsengi power plant. I think this might be a cold water hole. It has a depth of 2,5 km. This means that magma is at or close to that depth. Ground water in this area doesn’t go deeper than 1,9 to 3 km I think (I am not sure on how the fresh water ground level works in this area).
  • Eruption is expected from hours to day based on most recent measurements from Icelandic Met Office.
  • Grindavík town continues to sink according to news today (16. November 2023). Difference between days can be as much as 25 cm.
  • Mbl.is (Morgunblaðið) has a video of the damage done by this sinking on their website here. Its in Icelandic.

The situation for now is quiet, but that might only last for few hours to days longer before an eruption starts. Since earthquake activity strongly suggests that magma is looking for a way to the surface. While some magma is at shallow depth of 400 to 500 meters. There’s not enough of it to start an eruption. That can change without any warning at any time in this situation.

I’ll write updates if anything more happens here as quickly as I can.