Category: Reykjanes Ridge

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Update on earthquake activity close to Eldey island on Reykjanes ridge on 7th July 2023 at 13:31 UTC

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

  • Largest earthquake during the last 24 hours close to Eldey island had a magnitude of Mw4,5.
  • This earthquake swarm looks like a dyke intrusion. Since the area is out in the ocean it is impossible to be sure.
  • Difficult to know if an eruption is going to happen in this area. If an eruption happens, effects are unlikely to be big because of ocean depth.
A lot of green stars all over the place and a lot of red dots. Since there has been heavy earthquake activity on Reykjanes ridge and Reykjanes peninsula in last few days.
Strong earthquake swarm activity on Reykjanes ridge and Reykjanes peninsula. Copyright of this image belongs to Icelandic Met Office.

It is my opinion that is unlikely to be an earthquake activity that is connected to the inflation in Fagradalsfjall mountain. Those earthquakes are closer to Fagradalsfjall mountain. It can’t be ruled out, but is unlikely to be the reason for this activity. Earlier activity in this same area also makes this unlikely to be a tectonic earthquake activity. It can’t be ruled out. Areas out in the ocean are always more difficult to figure out than activity on land with easier access.

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Earthquake swarm close to Eldey and Eldeyjarboða á Reykjanes ridge

It seems that sometimes in the last 24 hours an earthquake swarm started close to Eldey and Eldeyjarboða on the Reykjanes ridge. Largest earthquakes seems to be around Mw3,2 to Mw3,7 or in around that magnitude. Since it is close to impossible to see the earthquakes on the map in all the activity that is happening close to Keilir mountain and Fagradalsfjall mountain.

Green stars out in the ocean is the activity on the Reykjanes ridge. There's a lot of activity on this map and the whole thing is a mess to read.
Heavy earthquake activity on the Reykjanes peninsula and Reykjanes ridge. Copyright of this image belongs to Icelandic Met Office.

I don’t know if this earthquake swarm is connected to what is happening in Fagradalsfjall mountain and Keilir mountain. It seems unlikely, but this activity might have been triggered by that earthquake swarm. What is going on there is unclear. Since this is out in the ocean.

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Reykjanes peninsula might be one large volcano

It was in the news today (3. July 2023), since inflation has been detected from GPS data on Reykjanes peninsula since start of April. What was told in a interview on Bylgjan (radio channel) and later published on Vísir.is news website (link below, but the whole thing is in Icelandic) is that all of Reykjanes peninsula is inflating. What is also starting to show in the GPS data is that there might not be separate volcanoes on Reykjanes peninsula, this might also have happened in the year 2020 – 2021, before the first eruption in Fagradalsfjall mountain. All of Reykjanes peninsula might be one large volcano, extending from Hengill to Eldey or Eldeyjarboða, the south end might have uncertain location. This changes everything as that means that it can erupt at any location on the Reykjanes peninsula without warning and the whole area is now in an eruption cycle.

The current period of inflation started in April and is now at 2,5cm (25mm) and is centered at the last eruption location in Fagradalsfjall mountain. That means the most likely location of next eruption is going to be Fagradalsfjall mountain. This inflation is also going to trigger large earthquakes on Reykjanes peninsula in next few weeks to months until an eruption starts. Along with the normal amount of small earthquakes that have been happening since April on the whole of Reykjanes peninsula.

I don’t know when or how long it is going to take to change the official definition of the Reykjanes peninsula. Because this is going to require more research and data collection for the scientists in Iceland. This also means a lot of new science papers have to be published and peer-reviewed.

Icelandic news

Fólk á suð­vestur­horninu má búa sig undir reglu­lega jarð­skjálfta (Vísir.is)

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Earthquake swarm in Reykjanes volcano

Today (26. June 2023) an earthquake swarm took place in Reykjanes volcano. This earthquake swarm is in a location in Reykjanes volcano that has been having repeated earthquake activity over the last few months. This strongly suggest that at this location there’s an active dyke that might erupt in the future.

Earthquake swarm out in the ocean close to Reykjanestá in the Reykjanes volcano. A lot of red dots piled on top of each other. Blue to orange dots located elsewhere on the Reykjanes peninsula. Time on map 26. June. 23. 16:05 (Icelandic Time).
Earthquake swarm in Reykjanes volcano. Copyright of this image belongs to Icelandic Met Office.

Largest earthquake in this swarm at the writing of this article had a magnitude of Mw3,0. Other earthquakes have been smaller in magnitude. I am unclear on how many earthquakes have happened in Reykjanes volcano at the writing of this article. This earthquake swarm is ongoing at the writing of this article.

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Increase in earthquake activity in Reykjanes and Fagradalsfjall volcano

During the night of 3. June 2023 an earthquake swarm took place in Reykjanes volcano, at location called Reykjanestá. Largest earthquake in that swarm had a magnitude of Mw3,0. Other earthquakes where smaller. This earthquake swarm suggests a magma movement, but it is difficult to be sure if that is what happened now.

Earthquake swarm out in the ocean next to Reykjanestá and there's also an earthquake activity in Fagradalsfjall volcano. Time on map is 03. june. 23 12:35 (Iceland time)
Earthquake activity in Reykjanes volcano and Fagradalsfjall volcano. Copyright of this image belongs to Icelandic Met Office.

Its been ten months since last eruption took place in Fagradalsfjall volcano. It is likely that a new eruption is going to happen soon, but it is impossible to know when. In last few weeks earthquake activity has been increasing in Fagradalsfjall volcano and that suggests that magma pressure inside the volcano is increasing. It just has not reached the levels to start a new eruption.

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Earthquake swarm in Reykjanes volcano (out in the ocean)

During the night of 4. May 2023 an earthquake swarm took place in the Reykjanes volcano out in the ocean. This was not a large earthquake swarm. Largest earthquake recorded had a magnitude of Mw3,4. Other earthquakes where smaller in magnitude.

Green star and a cluster of earthquakes on down and west part of this image. Showing the Reykjanes peninsula. Few other earthquakes are dotted on the map in other volcanoes on the Reykjanes peninsula.
Earthquake swarm in Reykjanes volcano. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity suggests an dyke intrusion in this area. This is part of Reykjanes volcano, but that volcano is in part out in the ocean. The Reykjanes volcano has been having regular dyke intrusion in recent years without it resulting in an eruption. That is most likely what is going to happen now.

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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.

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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.

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Earthquakes far off the coast on Reykjanes ridge

Yesterday (30. January 2023) had two earthquakes with magnitude Mw3,2 far off the coast on the Reykjanes ridge. Only one smaller earthquake was detected. Distance from the SIL network makes detection of smaller earthquakes is impossible or really difficult.

Two green star in the far left side of the image, one more close to the bottom of the image. Reykjanes peninsula on the right top part of the image.
Earthquakes on the Reykjanes ridge yesterday. Copyright of this image belongs to Icelandic Met Office.

Besides this earthquake activity, it remains quiet in Iceland. Bad weather has also been blocking detection of earthquake activity for the last two weeks.