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.

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.

Increased conductivity in Múlakvísl glacier river from Mýrdalsjökull glacier

Currently there’s a unusual high conductivity in Múlakvísl glacier river. There’s almost no earthquake activity in Katla volcano at the writing of this article. What is expected is that a new glacier flood might happen in next few days in Múlakvísl glacier river and other nearby glacier river possibly.

Few dots and a green star just west of Mýrdalsjökull glacier that is a ghost earthquake from Fagradalsfjall mountain activity in Katla volcano.
All quiet in Katla volcano. The green star is a ghost earthquake. Copyright of this image belongs to Icelandic Met Office.

Currently there are no clear signs that Katla volcano is about to start erupting.

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.

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.

Update on Fagradalsfjall activity at 11:40 on 5. July 2023

This is a short update since this situation is changing quickly.

  • Largest earthquake recorded so far had a magnitude of Mw4,8 and was felt over a wide area.
  • Uncertainty level has been declared for Fagradalsfjall mountain area because of this earthquake activity and the risk of an eruption.
  • Current depth of the magma is now 3 to 6 km and is getting shallower by each hour.
  • Over 2000 earthquakes have been recorded at the writing of this article.

 

A lot of earthquakes in Fagradalsfjall mountain. Time on image is 11:30 on 5th july 2023.
Earthquake swarm activity in Fagradalsfjall mountain. Copyright of this image belongs to Icelandic Met Office.

The only web camera that I know of at the moment and is showing Fagradalsfjall mountain is this one here. When the eruption starts, it should be visible in some part on this web camera. I hope that other closer web cameras are going online soon. Those where run by Rúv and mbl.is in last eruption.

Update on the activity in Fagradalsfjall mountain

This is a short update on the activity in Fagradalsfjall mountain.

Currently there have been around 200 earthquakes that have happened at the writing of this article. The first magnitude Mw3,1 took place at 22:45 UTC. This magnitude is automatic and is going to change when the earthquake is reviewed.

Green star and a lot of red dots in Fagradalsfjall mountain.
The heavy earthquake activity in Fagradalsfjall mountain. Copyright of this image belongs to Icelandic Met Office.

There’s a lot going on at the writing of this article and the situation can change without warning. I’ll post updates as best I can.

Two earthquakes in Bárðarbunga volcano

Because of other activity in Iceland. This article is going to be short.

Two earthquakes took place in Bárðarbunga volcano at 19:59 UTC and 20:02 on 4. July 2023. The magnitudes was Mw3,3 and Mw3,9.

Two green stars on top of each other in Bárðarbunga volcano in Vatnajökull glacier.
Earthquake activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

This is normal activity and happens because of inflation in Bárðarbunga volcano.

Earthquake swarm in Fagradalsfjall mountain

Today (4. July 2023) there has been a earthquake swarm in Fagradalsfjall mountain. Largest earthquake had a magnitude of Mw1,6 and at the writing of this article there have not been any earthquakes with magnitude above Mw2,0. This might change without warning.

Red dots in Fagradalsfjall and yellow and blue dots in other places on Reykjanes peninsula.
Earthquake activity on Reykanes peninsula. Copyright of this image belongs to Icelandic Met Office.

Smaller earthquakes swarms sometimes seems to happen before an eruption in Fagradalsfjall mountain. The current earthquake swarm has all signs of dyke intrusion. If that is going to result in eruption now is impossible to know.

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)