Harmonic tremor pulse during the night until morning in Fagradalsfjall volcano (9-March-2021)

This is a short article on the activity in Fagradalsfjall volcano. This situation is developing quickly and it is impossible to know what happens next.

During the night of 9-March-2021 from 05:20 UTC until around 07:00 UTC an harmonic tremor pulse was detected by Icelandic Met Office. This shows that the magma is still expanding into the Earth crust below Fagradalsfjall mountain and according to Icelandic Met Office it looks like the dyke is expanding in south direction but it is going to take a day or two to confirm that with GPS data.

Earthquake activity in the volcano Fagradalsfjall. Dots on a generated map my a program called Skjálfta-Lísa shows the most recent earthquake activity from midnight until 16:18
Earthquake activity in Fagradalsfjall volcano. This shows the possible location of the south end of the magma dyke. Copyright of this image belongs to Icelandic Met Office.

There have been fewer stronger earthquakes in last few days. While the there are fewer strong earthquakes the amount of earthquakes has not really dropped in any number, most earthquakes are small in magnitude and only few reach magnitude above Mw3,0. This quiet period is not expected to last for any amount of time while magma continues to be injected into the crust of Fagradalsfjall volcano. There continues to be a high risk for earthquake with magnitude Mw6,0 to Mw6,5 along with risk of Mw6,5 earthquake in Brennisteinsfjöll volcano. Currently no magma movement is being detected in Reykjanes volcano, Krýsuvík volcano or Brennisteinsfjöll volcano.

New information about the situation in Fagradalsfjall volcano

This is a short article about the new information published today (8-March-2021) by Icelandic Met Office and Department of Civil Protection and Emergency Management.

New measurements of the situation in Fagradalsfjall volcano show that the dyke intrusion continues to grow and as at its shallowest point at 1 km depth. Possible eruption is expected at the south end of the dyke intrusion (closest to Fagradalsfjall mountain). Earthquakes are going to happen at the south-west end of the dyke and north-east of the dyke because of the inflation the magma is creating in the area.

The dyke shown with dotted line and circle shows the most effective area. Gray areas at both ends shows earthquake effected area
The earthquake areas at the ends of the dyke intrusion, shown in gray areas on this map. The dyke is shown within the line with dot lines. Copyright of this image belongs to Icelandic Met Office.

There are going to be quiet times between high period of activity according to the news about this activity. There is also ongoing risk of a earthquake with magnitude of Mw6,5 in Brennisteinsfjöll volcano and according to Icelandic Met Office that risk has not been reduced in recent days. Outside of the Fagradalsfjall volcano magma dyke, no magma movement has been detected in Reykjanes (Svartsengi?) volcano and in Krýsuvík volcano.

Sources (Icelandic)

Áfram má búast við að virknin á Reykjanesskaga verði kaflaskipt (Iceland, English, Polish, Almannavarnir.is)
Kvikan er á kílómetra dýpi (Rúv.is, Icelandic)

Strong earthquake activity in Fagradalsfjall volcano

This article is short because the situation is always changing. Article is written at 07-March-2021 at 23:10 UTC.

At 00:22 UTC and until around 00:42 UTC an harmonic tremor was detected in Fagradalsfjall volcano. While this harmonic tremor only lasted for 20 minutes it started an earthquake swarm around 01:00 UTC that lasted until around 04:00 and the largest earthquake in that swarm had a magnitude of Mw5,0 to Mw5,2 (USGS/EMSC) at 02:01 UTC. Every day from 2500 to 3000 or more earthquakes are being recorded. Since 24-February-2021 over 24000 earthquakes have been recorded in this earthquake swarm. There is a massive inflation happening from Fagradalsfjall volcano and that is what is causing the earthquakes west and east of the dyke location between Fagradalsfjall mountain and Keilir mountain. Resulting in large earthquakes like the Mw5,0. Many of the earthquakes are happening close to the town of Grindavík and people there can’t sleep due to earthquake activity and the ongoing earthquake activity that is now happening at every minute.

Heavy earthquake activity on Reykjanes peninsula. Total of 68 green stars on the map and over 2600 other earthquakes of smaller magnitude are shown on the map at different age
Heavy earthquake activity in Fagradalsfjall volcano. Copyright of this image belongs to Icelandic Met Office.

It is now possible to check the inflation by viewing this GPS data website. Another website with GPS data can be found here and its is called Crustal Deformation.

More strong earthquakes are expected. If anything major happens I’ll post update soon as possible.

Web cameras directly streaming

Beint vefstreymi af skjálftasvæðinu – Efstaleiti
Beint vefstreymi af skjálftasvæðinu – Vogastapi (Rúv.is)
Keilir í beinni (mbl.is)
Óróasvæðið í beinni útsendingu (Vísir.is)
Live from Iceland
Keilir og skjálftasvæðið (YouTube)
Road camera 1
Road camera 2 (night vision/infrared)


Update 8-March-2021

A news article has been published showing the road damage from the recent earthquake activity. This is close to the HS Orka energy plant on Reykjanes peninsula.

Mal­bik sprungið við HS Orku í Grinda­vík (mbl.is, Icelandic, Pictures)

Article updated at 01:31 UTC.
Article updated at 04:36 UTC. Fixed web camera link that was broken (YouTube)
Article updated at 16:58 UTC on 8-March-2021. Fixed Rúv web camera link.

Update on Fagradalsfjall volcano activity on 7-March-2021 at 00:21 UTC

This is a short update on activity in Fagradalsfjall volcano. This is mostly on the activity on 6-March-2021.

Overview of current activity

  • Earthquake activity is mostly limited to small earthquakes.
  • Risk of eruption has not been reduced with current change in activity.
  • The magma dyke is at the shallowest on 2 km but it has an average depth of 5 km to 8 km depth.
  • Most of earthquake activity is closest to Fagradalsfjall mountain (north end?). The dyke is situated between Fagradalsfjall mountain and Keilir mountain.
  • Fagradalsfjall volcano has not erupted in last 12000 years.
  • There has not been any magma activity observed in Krýsuvík volcano and Reykjanes volcano (Svartsengi volcano?). All earthquake activity in those volcanoes are due to crust stress changes due to inflation from Fagradalsfjall volcano.

 

Dotted line showing the Fagradalsfjall volcano
The area of activity according to Icelandic Met Office. This might also be the Fagradalsfjall volcano. Copyright of this image belongs to Icelandic Met Office.

There remains a high risk of a strong earthquake with magnitude between Mw6,0 to Mw6,5 because of crustal stress changes that are connected to all the inflation that is now taking place in Fagradalsfjall volcano.

Dense earthquake activity in Fagradalsfjall volcano with many green stars showing earthquakes with magnitudes above Mw3,0 and many new red dots showing new smaller earthquakes
Dense earthquake activity in Fagradalsfjall volcano. Copyright of this image belongs to Icelandic Met Office.

Harmonic tremor has not been detected again since Wednesday but that might change without warning.

Current web cameras of Keilir mountain and possible eruption area

Beint vefstreymi af skjálftasvæðinu – Efstaleiti (Rúv.is)
Beint vefstreymi af skjálftasvæðinu – Vogastapi (Rúv.is)
Keilir í beinni (mbl.is)
Óróasvæðið í beinni útsendingu (Vísir.is)
Live from Iceland
Keilir og skjálftasvæðið (YouTube)
Road camera 1
Road camera 2 (night vision/infrared)

If anything major happens I’ll write a new article soon as I possibly can do so.

Update on activity in Fagradalsfjall and Reykjanes volcanoes

This is a short update on what is going on in Reykjanes peninsula. This article is written at 16:29 UTC.

Volcanoes in this article

Fagradalsfjall
Reykjanes
Krýsuvík

  • Fagradalsfjall volcano has not erupted since Pleistocene. When last eruption took place is not listed or not known. This the first magma movement in Fagradalsfjall volcano in 11700 years.
  • Eruption risk is now in Reykjanes volcano*.
  • *This might also be a different volcano known as Svartsengi (no Global Volcanism Profile). There is no agreements between maps on this detail for now. Reykjanes volcano might only extend into Reykjanestá and then is mostly under ocean and might not extend into Reykjanes peninsula as sometimes is shown on maps.
  • Krýsuvík volcano has quieted down a little in the last 24 hours. Eruption risk is lower for now in that volcano.
  • Largest number of earthquakes detected in one day was over 3000 earthquakes.
  • In the last 24 hours 12 earthquakes with magnitude above Mw3,0 have happened. Most of them are felt in nearby populated areas.
  • No harmonic tremor has been detected since it ended during the night on 4-March-2021.
  • During the last 48 hours over 3300 earthquakes have been recorded by Icelandic Met Office.
  • New! Magma is now estimated to be at 5 to 6 km depth but might be as shallow as 2 km depth.

 

Dense earthquake activity in the volcanoes Reykjanes, Fagradalsfjall and Krýsuvík volcanoes
Heavy earthquake activity on Reykjanes peninsula in three volcanoes. Copyright of this image belongs to Icelandic Met Office.

Maps of possible eruption areas has been made by Earth science department of University of Iceland and can be found here. University of Iceland Earth science department also made a lava flow prediction can that map can be found here. Both maps are updated daily on Facebook.

Web cameras

Beint vefstreymi af skjálftasvæðinu – Vogastapi (Rúv.is)
Keilir í beinni (mbl.is)
Óróasvæðið í beinni útsendingu (Vísir.is)
Live from Iceland
Keilir og skjálftasvæðið (YouTube)

Added at 21:12 UTC

Road camera 1
Road camera 2 (night vision/infrared)

Cameras and links might go offline without warning.

Donations

It is possible to support my work with donations. It helps me in current financial situation that has remained rather bad. You should only donate if you can. Other ways to support my website is to let people know about it if they are interested in earthquakes, volcanoes and geology in Iceland. Thanks for the support. 🙂

Article updated at 16:53 UTC.
Article updated at 21:13 UTC.

Update on activity in Fagradalsfjall, Krýsuvík, Reykjanes volcanoes

The situation on Reykjanes peninsula is getting complicated due to activity between three volcanoes. This article is written at 15:22 UTC.

The volcanoes that are now showing activity on Reykjanes peninsula

Reykjanes volcano
Krýsuvík volcano
Fagradalsfjall volcano (added from 04-March-2021)

Fagradalsfjall volcano has no document eruption history over the last 10.000 years and the main volcano location is unknown if it exists.

Updates from the last few hours

  • Small rift valley has started to form between Keili mountain and Fagradalsfjall mountain. This is part of the rift zone that is Reykjanes peninsula.
  • Harmonic tremor stopped this morning and as Icelandic Met Office has been telling the news the origins of this harmonic tremor was earthquake activity that was so dense it created this harmonic activity. In the morning the activity dropped a little.
  • Magma continues to move in the Fagradalsfjall volcano system.
  • Earthquake activity is now between the volcanoes Reykjanes, Fagradalsfjalls and Krýsuvík. Why that is unclear but magma movement for now is only in Fagrdalsfjall volcano system.
  • Largest earthquake in last 24 hours had a magnitude of Mw4,5. Over the last 48 hours total of 72 earthquakes with magnitude over Mw3,0 have taken place. There is no sign of activity slowing down.

 

Dense earthquake activity in Reykjanes volcano, Fagradalsfjall volcano and Krýsuvík volcano. A lot of red dots showing new earthquakes and green stars showing earthquakes with magnitude above Mw3,0 on Reykjanes peninsula
Heavy earthquake activity on Reykjanes peninsula in several volcanoes. Copyright of this image belongs to Icelandic Met Office.

It is currently impossible to know for sure what happens next since this situation is extremely complicated because of all the volcanoes interactions and earthquake activity.

Live internet broadcasts of Keilir

Beint vefstreymi af skjálftasvæðinu – Efstaleiti (Rúv.is)
Keil­ir í beinni (mbl.is)
Keilir og skjálftasvæðið (YouTube)

If anything major happens I am going to post update soon as possible.

Article updated at 15:38 UTC.

Krýsuvík volcano update at 19:56 UTC

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

No eruption has started at the writing of this article. Harmonic tremor is slightly lower compared to when it started at 14:20 UTC in Krýsuvík volcano. This drop in harmonic tremor started around 16:00 UTC. This harmonic tremor is ongoing as for writing of this article. There are no signs of the rift valley formation on the surface yet, but it does show up on measurements, both GPS and satellite measurements. Earthquake activity is high at the writing of this article but most earthquakes are small in magnitude but there are few earthquakes with magnitude of Mw3,0.

Earthquake activity in Krýsuvík volcano. A lot of green stars and red dots showing new earthquakes.
Earthquake activity in Krýsuvík volcano. Copyright of this image belongs to Icelandic Met Office.
The earthquake trace shows a dense dots of blue, yellow, orange and red dots. All are earthquakes of different magnitude
Earthquake activity trace of the earthquake activity on Reykjanes peninsula. Most earthquakes are in Krýsuvík volcano. Copyright of this image belongs to Icelandic Met Office.

Web cameras of the possible eruption area can be found in this locations.

Beint vefstreymi af skjálftasvæðinu (Rúv.is)
YouTube stream.

I am going to add more streams as I find them online.

I’ll update soon as possible if anything happens. This situation is changing quickly.

Harmonic tremor confirmed in Krýsuvík volcano – Eruption might be about to start

This article is written at 16:14 UTC. This is just a short update because the situation changes quickly.

Harmonic tremor has been detected in the Krýsuvík volcano. If an eruption happens as is now expected this is the first eruption in Krýsuvík volcano since the year 1340.

Harmonic tremor detected on SIL station Vogar. Copyright of this image belongs to Icelandic Met Office.
Earthquake activity in the Krýsuvík volcano. Copyright of this image belongs to Icelandic Met Office.

A rift valley has been confirmed to have formed in the Krýsuvík close to the area where the eruption is expected. This is between Keilir and Fagradalsfjall mountains. It is possible to watch live stream from this area on YouTube here.

Update at 16:41 UTC

Second web camera that is run by Rúv can be found here.

Next update when I know more.

Daily update on Krýsuvík volcano activity on 2-March-2021 at 20:07 UTC

This is a short update on the activity in Krýsuvík volcano. The activity has been confirmed to be only in Krýsuvík volcano and nothing is currently happening in Reykjanes volcano at the writing of this article.

Krýsuvík volcano started to show changes in late 2008 and early 2009 and that has been going on since then in low activity. Krýsuvík volcano is strange in that it does not have any shallow magma chamber in the top layers of the crust and Krýsuvík volcano size is unclear. This uncertainty shows in maps as different maps show different size and location of Krýsuvík volcano. While there is no shallow magma chamber in Krýsuvík volcano it does not rule out a deep, large magma chamber that does not show up on any seismometer since this magma chamber is located in the top layers of the mantle (10 to 30 km).

Green stars show the location of the earthquake activity in Krýsuvík volcano on Reykjanes peninsula. They are located on a small narrow band in almost south-west and north-east location and there is one cluster of earthquakes close to Trölladyngja tuff mountain
Earthquake activity in Krýsuvík volcano. Copyright of this image belongs to Icelandic Met Office.

Largest earthquakes since midnight had a magnitude of Mw4,6 and since around 12:00 it has been rather quiet in Krýsuvík volcano when it comes to large earthquakes. A lot of smaller earthquakes have been taking during all this time and there is no sign of those stopping. The reason for all this earthquake activity is a magma dyke that is now breaking its path up to the surface from around 10 km depth. There are nothing to suggest that process is about to stop or slow down. Drop in activity as is now happening are common feature of this type of dyke activity and was seen just before the eruption in Bárðarbunga volcano (Holuhraun) in 2014 to 2015.

Earth Science department of University of Iceland released a pictures that show how this dyke in Krýsuvík volcano works and that image can be viewed here on Facebook.

If anything major happens I am going to post an update soon as possible. Next update is tomorrow (03-March-2021) if activity remains as it currently is.

Article updated at 20:25 UTC. Fixes in the text.

Minor earthquake swarm north-east of Grímsey island

Yesterday (01-March-2021) at 19:53 UTC an magnitude Mw3,3 earthquake took place north-east of Grímsey island. This might be a new earthquake swarm in this area since earthquake swarms in Tjörnes Fracture Zone often star slowly. Earthquake swarms are common in this part of Iceland.

Green star and yellow and red dots north-east of Grímsey island
Earthquake activity north-east of Grímsey island. Copyright of this image belongs to Icelandic Met Office.

There is a chance of a stronger earthquake swarm in this area. Currently the activity remains small and nothing more might happen. This earthquake activity is not connected to what is happening on the Reykjanes peninsula.

Next article about Reykjanes peninsula activity is going to be written tomorrow (2-Mars-2021) unless something major happens.