Earthquake swarm in Ljósufjöll volcano

Yesterday (16. January 2025) an earthquake swarm started in Ljósufjöll volcano. This is an area that has had an earthquake swarm since 2020 or 2021. Largest earthquake in this swarm had a magnitude of Mw3,2.

Green star and a lot of small dots showing the earthquake in the Ljósufjöll volcano.
Earthquake activity in Ljósufjöll volcano system. Copyright of this image belongs to Icelandic Met Office.

This earthquake swarm aligned it self with fault lines in the area. That is a change from earlier earthquake activity. Depth of the earthquake has also been decreasing. Its now around 14 km, from 17 to 23 km as it was before. Based on the earthquake activity, the amount of magma remains low and when the amount of magma is low. Its less likely to erupt. It rather is just stuck in the crust. However, if the amount of magma increases, that is going to increase the chance of an eruption in this area. This might take years, if not decades to happen as it stands now. Quick change seems unlikely at the writing of this article.

Dyke intrusion into Bárðarbunga volcano

Today (14-January 2025) at 06:08 UTC an dyke intrusion started in Bárðarbunga volcano. This dyke intrusion lasted until around 09:00 UTC and might still not be over, even if the activity has stopped at the writing of this article. Largest earthquakes had the magnitude of Mw5,2 (USGS, EMSC). More than a dozen earthquakes with magnitude from Mw3,0 to Mw5,0 took place in this earthquake swarm.

Row of green stars in Bárðarbunga volcano caldera. Few small earthquakes are in Grímfjall volcano, an activity unrelated to this activity in Bárðarbunga volcano.
The earthquake activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

The main activity was in the western part of the caldera. According to the experts, this earthquake swarm looks close to what happened in Bárðarbunga volcano before it erupted in Gjálp (Wikipedia, Icelandic) in the year 1996. Then a earthquake swarm started like this, slowed down for few days before it increased again and the eruption happened. It is unclear what direction the dyke might move to, but most likely is south-west in the direction of Torfajökull volcano and Katla volcano. If that happens, such dyke activity might get those volcanoes upset or start and eruption in them.

I am going to post update as needed for Bárðarbunga volcano as this activity continues.

The earthquake swarm in Reykjanes volcano, close to Eldey island

On Sunday (29-December 2024) and yesterday (30-December 2024) an earthquake swarm took place in Reykjanes volcano, close to Eldey island. Largest earthquakes in this earthquake swarm had magnitude of Mw3,2 and Mw3,6. Over 200 earthquakes have been recorded at the writing of this article. This earthquake activity is possibly still ongoing. But this earthquake activity happens in waves with quiet time period between them.

Two green stars and small dots on Reykjanes ridge showing smaller earthquakes. A lot of smaller earthquakes on Reykjanes peninsula.
Earthquake activity on Reykjanes ridge. Copyright of this image belongs to Icelandic Met Office.

It is unclear if this earthquake activity is because of tectonic movement or magma activity. I do suspect that this activity is because of magma movement in this area, based on earthquakes location, since it was focused on rather small locations. There are however no signs that this earthquake swarm is a start of an eruption at this location currently. There are limited GPS data on Reykjanes volcano, since part of it is under the ocean.

Earthquake activity in Hamarinn volcano

Today (19-December 2024) at 12:18 UTC an earthquake with magnitude of Mw3,1 took place Hamarinn volcano. Few smaller earthquakes also followed, there was also small amount of earthquakes before the largest earthquake.

Green star in western Vatnajökull glacier, just south of Bárðarbunga volcano. This is Hamarinn volcano. Few dots showing smaller earthquakes in this area.
Green star in Hamarinn volcano. Copyright of this image belongs to Icelandic Met Office.

Last time this happened in Hamarinn volcano an eruption that lasted 6 to 8 hours happened in July 2011. When or if an eruption happens in Hamarinn volcano is impossible to know. This activity might quiet down again. If there is a ongoing increasing earthquake activity, then a eruption in Hamarinn volcano is more likely, but it is impossible to know if it is going to happen.

Strongest earthquake in Ljósufjöll volcano since start of modern recording

Yesterday (18-December 2024) at 22:50 UTC. The strongest earthquake since modern recording started took place in Ljósufjöll volcano. This earthquake was felt in Borgarnes, Akranes and other nearby towns. Magnitude of this earthquake was Mw3,2 at depth of 18 km. The reason for this earthquake is injection of magma at depth at this location.

Green star and blue and orange dots showing the smaller earthquakes.
The earthquake activity in Ljósufjöll volcano. Copyright of this image belongs to Icelandic Met Office.

As it looks now. An eruption is unlikely to happen in Ljósufjöll volcano. In the last few months, the depth of this earthquake activity has not changed that much and continues to be at 15 to 25 km depth in this area. The crust is also thicker and more dense in this part of Iceland and that requires more magma to break up to the surface. At the writing of this article, that has not changed since this earthquake activity started. As more magma injects into this location is going to result in more earthquakes. Currently, the amount of magma in this injection seems to be minor and is unable to break a path to the surface.

Earthquake swarm in Hofsjökull volcano

One of Iceland largest volcanoes has been having an earthquake swarm this evening on 13-December 2024. This is the Hofsjökull volcano. Largest earthquake in this swarm had a magnitude of Mw3,3 at 8,8 km depth. Other earthquakes have been smaller.

Green star and two blue dots and one yellow dot in north part of Hofsjökull volcano. The green star is located in the western part of caldera edge. Hofsjökull glacier and the volcano is on the centre on this image.
Earthquake activity in Höfsjökull volcano. Copyright of this image belongs to Icelandic Met Office.

This earthquake swarm seems to be over. However, the problem with Hofsjökull volcano is that earthquake activity often stops and then resumes several hours to days later in the same location. If that happens now I do not know.

Magnitude Mw5,2 earthquake in Bárðarbunga volcano

During the night of 8-December 2024 at 01:49 UTC an earthquake with magnitude of Mw5,2 took place in Bárðarbunga volcano. This is a inflation related earthquake, as Bárðarbunga volcano continues to inflate from the collapse during the 2014 and 2015 eruption.

Green star in Bárðarbunga volcano, showing the largest earthquake. With lot of smaller dots in the caldera.
The earthquake activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

A lot of smaller earthquakes also happened before and after the main earthquake. This is not unusual, there are just more of them now. Why that happened is not clear. This is an ongoing earthquake activity in Bárðarbunga and is going last for the next 30 to 90 years in the longest. Depending on how this evolve in Bárðarbunga volcano.

Eruption has started in Sundhnúkagígaröðinni in Svartsengi volcano

Yesterday (20-November 2024) at 23:29 or 23:30 UTC an eruption started in Sundhnúkagígaröðinni in Svartsengi volcano. This is the earliest that eruption has started in this location for the last year since this eruption sequence started in Svartsengi volcano. The time between eruption is however among the longest ones or 77 days. The fissure that the eruption is happening in is at current time around 3 km long.

Red dots along the Sundhnúkagígar crater row as it started erupting in Svartsengi volcano.
The earthquake activity in Sundhnúkagígar crater row. Copyright of this image belongs to Icelandic Met Office.
The lava fountains of the eruption as it started at 23:25 UTC in Iceland. Cloud of gas drifts towards south as wind is blowing from the north.
Early in the eruption in Sundhnúkagígaröðinni. Screenshot from Rúv web camera.
The eruption at 00:53 UTC. The lava fountains are lower and the gas cloud is smaller. Lava is seen flowing to the west from the eruption.
The eruption at 00:53 UTC in Sundhnúkagígaröðinni in Svartsengi volcano. Screenshot from Rúv web camera.

The harmonic tremor signal at the start of the eruption was very small. Suggesting that this eruption is not that large. If that holds true, it is possible that this eruption is not going to last that long and might be over by next week at the longest. Only time is going to tell if that happens or not. The main eruption happens in the first 6 to 8 hours.

If needed. I’ll write a new update on what is going on.

Earthquake in Askja volcano

Yesterday (10-November 2024) at 08:13 UTC an earthquake with the magnitude of Mw3,0 took place in Askja volcano. This earthquake had few minor aftershocks, but nothing more happened following this earthquake.

Green star at the end of this map. In Askja volcano. There is one blue dot, showing a smaller earthquake in Krafla volcano.
Earthquake activity in Askja volcano. Copyright of this image belongs to Icelandic Met Office.

There is magma flowing into Askja volcano at current time. However I do not think this time it is going to result in a eruption. If this earthquake is connected to this magma inflow I do not know.

Small dyke intrusion into Sundhnúkagígar in Svartsengi volcano during the night (4-November 2024)

During the night of 4th November 2024 at 02:30 to around 03:00 UTC an small dyke intrusion took place in Sundhnúkagígar crater in Svartsengi volcano. Around 20 to 25 earthquakes took place in this minor dyke intrusion that stopped as quickly as it had started.

Dots of small earthquakes all over Reykjanes peninsula. The dots in Svartsengi volcano, in Sundhnúkagígar crater row. This group of small earthquakes is the dyke intrusion that was trying to happen during the night.
Earthquakes in Svartsengi volcano, Sundhnúkagígar crater row. Copyright of this image belongs to Icelandic Met Office.

There is a ongoing risk of more sudden dyke intrusion like this. Those can go on for hours and might not even erupt at all. A lot more earthquake activity is going to happen if such a dyke intrusion happens.