Category: Keilir

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Increased hydrothermal activity between Keilir mountain and Trölladyngja mountain

Rúv News is reporting today (10. September 2023) that there has been noticeable increase in hydrothermal activity east of Keilir mountain since end of least eruption close to Litli-Hrútur mountain. According to the news, this shows that magma is now close to the surface without erupting currently. This area is rather large, it is between Keilir mountain and Trölladyngja mountain (part of Krýsuvík-Trölladyngja volcano). There have been reports of increased SO2 vents that is killing moss in this area, along with new steam vents that have been appearing in the last few weeks.

According to Þorvaldur Þórðarson volcanologist, there is a magma shadow in the area around Trölladyngja and that appeared around the time the eruption close to Litli-Hrútur started. This area was noticed by Thomas Fisher earthquake expert from Czech Republic did notice this area having almost no earthquakes at all. Showing that magma has pushed it self into the crust at this location at shallow depth.

The result of this is that next eruption might have more eruption vents, it might erupt at more than one fissure at the same time in parallel. What happens next is unclear, but this large area has gotten really warm and seems to be continuing to expand.

Rúv news

Fylgjast vel með auknum jarðhita austan við Keili (Rúv.is, has map of the area)

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Update on the eruption close to Litli-Hrútur on 23. July 2023 at 21:22 UTC

This is a short update. Since there is not a lot of information about this.

  • The crater might collapse at any time without warning. Geologists that monitor the eruption have noticed that the crater has started to get larger and is now full of lava. This means it is going to collapse. What direction is not known. It is my view that it is going to collapse to the east because of least resistance in that direction.
  • When the crater collapses the lava is going to flow more than 100m/s in whatever direction it flows.
  • Tourists are in high danger close the crater because of this collapse risk.
  • Dyke intrusion has been detected east of Keilir mountain. Along with increased ground temperature, that means the magma is at shallow depth in the crust. This area might erupt soon in similar way as is now happening close to Litli-Hrútur.

This is all the information I have now and only thing that has changed in the eruption in the last 13 days.

Icelandic News

Veggir gígsins muni hrynja innan skamms (Vísir.is)

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Update on the eruption at Litli-Hrútur on 11th July 2023 at 17:18 UTC

This article is short. The eruption is mostly stable at the writing of this article but the situation can change quickly without warning.

  • The eruption has changed in last few hours. It seems to be in only one crater that is slowly forming. The eruption has stopped at the north most end of the eruption fissure. At the writing of this article.
  • The dyke now extends 1 km under Keilir mountain in the direction of north-east. This might be a new dyke intrusion and not connected to the dyke that started the current eruption. This might result in a second eruption soon, but its too early to know for sure at the writing of this article.
  • The eruption started large fires in the moss and other plants in this area around Litli-Hrútur. This has resulted in massive toxic smoke in this area.
  • There’s a high risk of the volcano gas from the eruption, along with the toxic smoke from all the plants and moss burning.
  • Interestingly, while earthquake activity has dropped it has not stopped. Why that has happened is a bit of a mystery, it might be connected to the possible new dyke that has formed under Keilir mountain.
  • Yesterday (10. July 2023) the longest the fissure extent was at 1500 meters or 1,5 km. Since then it has gone down to one erupting crater that seems to be 50 meters to 100 meters long.
Map of the magma dyke and the eruption fissures on a map from Icelandic Met Office and others. Orange area between Keilir and to Meradalir valley show the danger area around the eruption area.
Map of the danger area around the eruption. The orange area is the danger zone that people should not travel over. Copyright of this image belongs to Icelandic Met Office and others.

 

It is impossible to know how long this eruption is going to last. Since dyke intrusions are poor magma containers this eruption might be a short one if there isn’t a constant supply of fresh magma from the deep mantle. Its too early to know if that is the case here. I have also noticed that once the eruption ends in any area, that area is not going to erupt again. When the eruption ends, it ends forever and that makes this a single eruption activity or crater rows. This area might be Monogenetic volcanic field (Wikipedia).

Since this type of eruptions are mostly uneventful and just continue. I plan on only posting updates when there are some news or changes to the eruption happen.

Update at 17:41 UTC

ISOR is reporting that their station called FAF (Fagradalsfjall) has to be moved because the lava is flowing directly at it. They are going to find a new location for this station. This report can be seen here on Facebook in Icelandic.

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Update on the eruption at Litli-Hrútur on 10th July 2023 at 18:41 UTC

This is a short update because events are changing quickly.

  • Length of the eruption fissure is uncertain, reports are conflicting. The numbers I’ve seen are from 200 meters to 900 meters long. This also might be a case of growing fissure eruption.
  • Harmonic tremor on the SIL station Fagradalsfjall continues to grow. Suggesting that the eruption is increasing in power since it started. This sometimes happens in lava eruptions.
  • The lava is flowing to the south. It might reach Meradalir valley in about one  week to three weeks. Some of the lava is flowing to the north, but a lot of less of it and is only expected to flow in the nearby area. There is no risk at current time for any damage to infrastructure or property.
  • There’s a risk of new fissures opening up in this area without warning.
  • This area is remote and difficult to go towards. Police has closed roads for the time being for safety reasons.

I’ll post new update soon as I have any new information or if anything changes. Experience has shown that this type of eruptions are rather uneventful for a longer time periods. I’ll adjust my updates in accordance with that.

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Strong earthquake 1,4 km east of Keilir mountain

Today (9. July 2023) at 22:22 UTC an earthquake with magnitude of Mw5,2 happened 1,4 km east of Keilir mountain. This earthquake did shake Keilir mountain and resulting a small dust cloud. This earthquake is connected to inflation that is happening just south of Keilir mountain, rather than being connected directly to magma movements in this area.

A lot of green stars close to Keilir and Fagradalsfjall on Reykjanes peninsula map. Time on map is 9th July 2023 at 23:15 UTC.
Strong earthquake activity in Fagradalsfjall mountain and Keilir mountain. Copyright of this image belongs to Icelandic Met Office.

There’s a risk of more strong earthquakes like this in this area until an eruption starts.

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Update on activity in Fagradalsfjall – Keilir mountains on 9th July 2023 at 16:11 UTC

This is a short update, because there’s little to report.

  • Three earthquakes with magnitude above Mw4,0 took place north east of Keilir mountain in the last 24 hours.
  • Earthquake activity is increasing north-east and north of Keilir mountain. Why is unclear, it is a possibility that magma is creating a path for it self that way.
  • The magma seems stuck in the crust and there doesn’t seems to have stopped the inflow of magma from the deep mantle. This is going to result in increased pressure in the dyke until an eruption happens.
  • Risk of strong earthquakes is high and might get higher until an eruption starts.

 

Heavy earthquake activity remains in Fagradalsfjall - Keilir area. With the new activity area north-east of Keilir mountain. Time on map is 9 July 2023 at 15:55 UTC.
Heavy earthquake activity in Fagradalsfjall – Keilir mountain. Copyright of this image belongs to Icelandic Met Office.

Since the start of this activity, around 12000 earthquakes have been recorded by Icelandic Met Office according to the news. Strongest earthquake at the writing of this article is at magnitude Mw4,8.

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Update on the activity in Fagradalsfjall mountain on 7th July 2023 at 14:28 UTC

This is going to be a really short article. Because an eruption might be about to start. Difficult to be sure, but there’s a chance. Eruption has not started at the writing of this article.

  • Largest earthquake in the last 24 hours seems to be a magnitude Mw4,3. I no longer can keep up with all this earthquake activity.
  • Inflation in area close to Keilir has reached 200mm (20cm) in less than 48 hours when this started.
  • Inflow of magma is estimated to be 88m3/s and that is a lot of magma moving and moving fast.
A lot of earthquakes in Fagradalsfjall mountain. Too many earthquakes too count and too many green starts.
Heavy earthquake activity in Fagradalsfjall mountain. Copyright of this image belongs to Icelandic Met Office.

It is unclear where the eruption is going to happen. But there has been a drop in earthquake activity that strongly suggest that magma is close to finding a path to the surface. According to measurements, the magma is now less than 1 km away from the surface.

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Update on activity in Fagradalsfjall mountain on 6th July 2023 at 14:20 UTC

This is a short update because there’s a lot going on.

  • Earthquake activity started to drop around 04:00 this night according to Icelandic Met Office and seems to continue to drop at the writing oft his article. This suggests that an eruption might be getting close in time.
  • Strong earthquakes might still happen even if earthquake activity is dropping.
  • Movement on GPS is close to 50mm in some locations. That’s a lot more than in earlier eruptions. When it was at most from 15mm to 25mm in some locations. Movement is not equal in all directions and location on GPS.
  • During the day the earthquakes started to move south again towards Fagradalsfjall mountain. At the same time, number of earthquakes dropped.
  • Here are the web cameras I know of as writing of this article. Rúv, Reykjanes North, Reykjanes south, Live from Iceland, Fagradalsfjall, Live from Iceland, Langihryggur, Morgunblaðið, Perlan.
  • It is impossible to know when an eruption starts.

 

A lot of green stars and red dots in Fagradalsfjall mountain and on Reykjanes peninsula because of misplaced earthquakes.
Strong earthquake activity in Fagradalsfjall mountain. Copyright of this image belongs to Icelandic Met Office.

How long the wait until an eruption happens is impossible to know. Because of activity in this area in the last two years, the crust around Fagradalsfjall mountain and nearby areas is weak and can allow magma to pass more easily then it otherwise would. It remains a question if there’s some type of block that the magma can’t get trough close to Keilir mountain. Magma is always going to find path of least resistance and erupt at that location. That location is now somewhere between Keilir and Fagradalfjall mountains.

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Update on Fagradalsfjall mountain activity at 16:35 UTC on 5th July 2023

This is a short update since there is a lot going on.

  • Largest earthquake recorded at the writing of this article is Mw4,8 from earlier this morning.
  • Larger earthquakes are growing in numbers. There is now also a warning for possible Mw6,3 earthquake on Reykjanes peninsula following this earthquake swarm and dyke intrusion into Fagradalsfjall mountain.
  • The dyke intrusion is coming up just south of Keilir mountain.
  • Based on what I am seeing, it is possible that current dyke intrusion into Fagradalsfjall mountain is larger than the first eruption in March 2021. If this is accurate is a wait and see situation until an eruption starts.
  • It is possible to view the earthquake activity in real time here, at Raspberry Shake website.

 

A lot of green stars and red dots in Fagradalsfjall mountain on Reykjanes peninsula. Time on map is 5. July 2023 at 16:25 UTC.
Heavy earthquake activity in Fagradalsfjall mountain. Copyright of this image belongs to Icelandic Met Office.

All data now suggest that an eruption is going to happen. Where it is going to start erupting is impossible to know and it is not possible to know when it is going to start erupting.

I’ll try to post update when more is known about what is going on.