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.

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.

Strong earthquake swarm in Reykjanes volcano on Reykjanes ridge / Reykjanes peninsula

This earthquake swarm is ongoing at the writing of this article and information can change without warning. The largest earthquake recorded by automatic magnitude of Mw3,7 at the writing of this article. Around 30 to 40 earthquakes have happened so far, but that number might change quickly. This earthquake activity has some signs that it might be happening because of magma intrusion in the area, out in the ocean but signals are not clear.

Three green stars and red dots on the left down side on the map of Reykjanes peninsula, the earthquake activity is happening out in the ocean on the Reykjanes ridge.
The current earthquake activity on Reykjanes ridge. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity is in the volcano Reykjanes, that volcano goes into the ocean and is on dry land. Making possible future eruptions both explosive and flowing magma at the same time. To date, Reykjanes volcano only has had earthquake swarms and no eruption. When that is going to change is impossible to know.

Small earthquake swarm in Bárðarbunga volcano

Today (7. February 2023) an small earthquake swarm took place. This earthquake swarm started at 11:21 UTC with a magnitude Mw3,2 earthquake and lasted until 12:05 UTC. Other earthquakes were smaller in magnitude.

Green star in the west side of Vatnajökull glacier, were the largest earthquake took place in Bárðarbunga volcano. Few other red dots at the same location show the smaller earthquakes.
Earthquake activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

This shows that Bárðarbunga volcano continues to inflate at high rate. Based on what happened before the eruption in 2014 to 2015 in Bárðarbunga volcano. When the earthquake stop for long time period it means Bárðarbunga volcano is ready for an eruption. While the earthquake activity happens is it is doing today, it means inflation continues in Bárðarbunga volcano.