Earthquake swarm east of Grímsey island in Tjörnes Fracture Zone

Yesterday (9. March 2023) and today (10. March 2023) an earthquake swarm has been east of Grímsey island. Largest earthquake in this swarm had a magnitude of Mw3,8. There have been around 40 to 60 earthquakes in this swarm. Making this earthquake swarm rather small, compared to many other earthquake swarm that have been at this same location.

Green star east of Grímsey island, in a circle that shows a submarine volcano at the same area. Red dots are in the same area showing smaller earthquakes.
Earthquake activity east of Grímsey island. Copyright of this image belongs to Icelandic Met Office.

This earthquake swarm seems to be ongoing at of the writing of this article. It is impossible to know for sure if an stronger earthquake is going to happen in this area.

Earthquake swarm in Katla volcano

Today (9. March 2023) an earthquake swarm started in Katla volcano. This earthquake swarm is ongoing and information in this article can go outdated quickly. Largest earthquakes at the writing of this article have a magnitude of Mw3,3 and Mw3,4. A swarm of smaller earthquakes is ongoing.

Two green stars in Katla volcano askja in Mýrdalsjökull glacier. Along with many red dots that show smaller earthquakes in Katla volcano.
Earthquake activity in Katla volcano. Copyright of this image belongs to Icelandic Met Office.

It is difficult to know for sure what is going on in Katla volcano. But this activity reminds me of what happened few years ago before an small eruption took place in Katla volcano. If that is going to happen now I don’t know. I’ll post information when I know more and if anything more happens in Katla volcano.

Earthquake swarm north of Herðubreið mountain

Yesterday (5. March 2023) at 18:00 UTC an earthquake with magnitude Mw3,4 took place north of Herðubreið mountain. This is a small earthquake swarm and is part of an ongoing earthquake swarm in this area that has been going on since October 2022 (or in around that month).

Green star and red dots north of Herðubreið mountain, that is located north-east of Askja volcano. Smaller earthquakes in Askja volcano shown with blue and yellow dots.
Earthquake activity north of Herðubreið mountain. Copyright of this image belongs to Icelandic Met Office.

Depth of this earthquake was only 4,2 km and earthquake activity in this area has been getting shallower with time. If this is magma, then there’s not a lot of it at this depth. Earthquake activity is small compared to the earthquake swarms that happen just before an eruption. It is clear that, if this is magma, it is not pushing its way up the surface at this point in time.

The earthquake activity in Skaftafellsfjöll mountain (part under Vatnajökull glacier)

Since May 2011 there has been an earthquake activity in mountain called Saftafellsfjöll. This is slightly north of Öræfajökull volcano and south of Grímsfjall volcano. This earthquake activity is now permanent in this area it seems. Some of it might be glacier quakes, but most of the earthquake activity there is not, because of the depth this earthquake activity is happening at.

Earthquake activity in Skaftafell in Skaftafellsfjöll mountain. Shown as blue, orange and yellow dots on the map of Vatnajökull glacier. Also on this map is earthquake activity in Askja volcano and Herðubreið shown with red dots.
Earthquake activity in Skaftafellsfjöll mountain. Copyright of this image belongs to Icelandic Met Office.
One year worth of earthquake data from Skjalftalísa program on Icelandic Met Office. It shows a clear concentration of earthquakes in Skaftafellsfjöll mountain over this time.
Earthquake activity in Skaftafellsfjöll mountain for 365 days. Picture is from Skjálftalísa on Icelandic Met Office website. Copyright of this image belongs to Icelandic Met Office.

I don’t know for sure what is going on. This earthquake activity clearly shows that something is going on in this part of Vatnajökull glacier. It is my unverified opinion that there is a volcano there. Its not documented and map only show a extinct volcano in this area. This is unlikely to be earthquake activity in extinct volcano, its not impossible, what makes this unlikely is that this earthquake activity happens regularly and has been going on since May 2011. There is ice quake activity in this same area, but some of this earthquake activity is both deep and being located in areas with no glacier. If those are not measuring errors or something like that (I find that unlikely in many cases). I don’t think there’s going to be an eruption in this area, at least not for a long time if it ever happens. This earthquake activity might have been going on for a lot longer then from May 2011.

– This is not an registered or confirmed volcano in this area. Unless there’s an eruption, it might be a long time until a confirmation happens.

Earthquake activity in Katla volcano

Yesterday (26. February 2023) and today (27. February 2023) there was an earthquake activity in Katla volcano. This is mostly normal activity in Katla volcano and no signs of an eruption or that an eruption is about to start. Largest earthquake in this swarm had a magnitude of Mw3,2. I don’t know if it was felt in nearby area.

Yellow dots and green star in Katla volcano caldera that is under Mýrdalsjökull glacier that is shown in white on this image, along with other nearby volcanoes. The askja of Katla volcano is shown as elongated circle.
Earthquake activity in Katla volcano. Copyright of this image belongs to Icelandic Met Office.

There is no change in harmonic tremors or other activity in Katla volcano. That means this is just an earthquake activity and there is no sign that an eruption is about to happen.

People in eastern Iceland told to prepare for possible eruption in Askja volcano

Rúv News is reporting that people in eastern Iceland should look up information on how to deal with possible volcano ash from Askja volcano. This is an general advice to people in eastern Iceland because of possible eruption in Askja volcano, that can start without any warning or little warning. There is some risk of eruption in Askja volcano that might create an ash cloud, but there is also a chance that if Askja volcano erupts that the eruption is going to be a lava flow eruption, close to what happened in Bárðarbunga volcano in 2014 to 2015 eruption.

There is a possibility that the eruption from Askja volcano is going to go south, into the new Holuhraun lava field and craters after the Bárðarbunga volcano eruption of 2014 to 2015. There has been some earthquake activity in that area in recent weeks and there might be a weakness in the crust at that location that was not sealed during last eruption. What happens is only going to be clear once an eruption starts and until then its all just speculation.

Icelandic News about Askja volcano

Íbúar á Austurlandi ættu að kynna sér leiðbeiningar um öskugos (Rúv.is, Icelandic)

Earthquake swarm close to Geirfugladrangur on Reykjanes ridge

Today (21. February 2023) an earthquake swarm started close to Geirfugladrangur on Reykjanes ridge. This is possibly in another volcano than Reykjanes volcano that is just east of this location, this is because of distance and its unlikely that Reykjanes volcano extends this far south. It has no other name than Geirfugladrangur. Largest earthquake in this swarm had a magnitude of Mw3,1 and this earthquake swarm is ongoing and stronger earthquakes are a possibility.

Earthquake swarm on the Reykjanes ridge, marked by orange and green star were the largest earthquake took place. A lot of yellow dots close to Reykjanestá area.
Earthquake swarm on Reykjanes ridge. Copyright of this image belongs to Icelandic Met Office.

This earthquake pattern seems to indicate that a magma dyke intrusion is taking place. This area of the Reykjanes ridge last erupted in 16th to 18th century and has been quiet since.

Light sized earthquake in Bárðarbunga volcano

Today (21. February 2023) at 08:41 UTC an earthquake with magnitude of Mw4,9 took place in Bárðarbunga volcano. This is because of inflation that is now happening in Bárðarbunga volcano and has been going on since end of Holuhraun eruption in 2015. Earthquakes with this type of magnitude are going to happen once or twice a year until Bárðarbunga volcano is ready for next eruption and that can take decades. There are going to be smaller earthquakes between larger earthquakes. According to the news, this earthquake was felt in Akureyri.

Green star and red dots in Bárðarbunga volcano inside Vatnajökull glacier. Few dots in other volcanoes in this part of Iceland.
Earthquake activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

Last time this happened it took 112 years between eruptions in Bárðarbunga volcano. With the quiet period between 1902 and until 2014. Shortest time between eruptions seems to be around 40 years, but most eruptions happen between 90 to 112 years from last eruption. Based on the data from Global Volcanism Program on Bárðarbunga volcano. There is a lot of uncertainty in this data, so this might be shorter from what it looks like in the data.

I’ve switched to using standard definition for earthquake magnitudes, as shown here (Wikipedia). This is for clarification and simplification when I am writing about earthquakes.

Earthquake swarm north of Herðubreið mountain

Today (17. February 2023) at 09:26 UTC an earthquake with magnitude of Mw3,5 took place around 4 km north of Herðubreið mountain. This earthquake seems to have started an earthquake swarm in that area. It is unclear if this earthquake activity is connected to inflation that is taking place in Askja volcano.

Green star north of Herðubreið mountain. This is east of Askja volcano. Few dots of smaller earthquakes also in Askja volcano.
Earthquake activity in Herðubreið mountain. Copyright of this image belongs to Icelandic Met Office.

There has been increase in earthquake activity at this location in Herðubreið mountain, but why is unclear.

Strong earthquake swarm north of Kolbeinsey island [Updated]

Today (14. February 2023) at 01:24 UTC an earthquake swarm started around 70 to 90 km north of Kolbeinsey island. It might be in Kolbeinsey island. Largest earthquakes recorded at the writing of this article had a magnitude of Mw3,5 according to Icelandic Met Office. EMSC is reporting two earthquakes with magnitude of mb4,5 at the writing of this article.

Two green stars far north of Iceland in the ocean. Showing the location of the earthquakes north of Kolbeinsey island. This is all view map of Iceland and shows all the other earthquakes that have taken place in Iceland for the last 48 hours.
Earthquake activity north of Kolbeinsey island. Copyright of this image belongs to Icelandic Met Office.

Distance from land makes it difficult for the SIL network that Icelandic Met Office runs to detect the smallest earthquakes. This means there can be a lot more going on that appears on earthquake maps. There’s always a chance of stronger earthquakes in this area north of Iceland.

Update
Update at 16:50 UTC on 14. February 2023

Icelandic Met Office has finished reviewing the earthquake activity north of Kolbeinsey and around eight earthquakes with magnitude above Mw3,0 took place. Largest earthquake had a magnitude of mb4,6 according to EMSC. Information about that earthquake can be found here.

Ten green stars far north of Iceland showing the earthquake activity north of Kolbeinsey island. Other earthquakes that also happen in Iceland are visible on this map.
Earthquake activity far north of Iceland. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity appears to be over, but distance from seismic detection networks in Iceland prevents detection of smaller earthquakes that might be happening at this location.