Category: Harmonic tremors

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Overview of the eruption in Geldingadalur in Fagradalsfjall mountain

This is a short overview of the eruption that is now ongoing in Geldingadalur in Fagradalsfjall mountain area. This is part of Krýsuvík-Trölladyngja volcano system according to latest information. This information might change as the time and more information is collected. This article is written on 20-March-2021 at 02:58 UTC.

  • This is the first eruption in Krýsuvík-Trölladyngja volcano system since the year 1340.
  • The eruption started at 20:45 UTC according to Icelandic Met Office.  The harmonic tremor from the eruption is almost invisible.
  • The fissure is at the writing of this article estimated about to be 1 km long with the direction south-west and north-east.
  • Currently the eruption is small and there is no risk of damage to any infrastructure. Next road (currently closed because of earthquake damage) that might get damaged is 2,5 km distance from the eruption site.
  • This eruption suggests that more eruption might start in different fissures once this eruption is over.
  • The valley that the lava is flowing into might get filled with lava if the eruption lasts long enough. The valley next to it is equally deep so there is no danger of this lava flow.
  • The eruption is in a area that is difficult to access even by a car.

 

The earthquake activity in the dyke between Fagradalsfjalls and Keili. Mostly just minor eartquakes show by red dots
The earthquake activity in the dyke. Copyright of this image belongs to Icelandic Met Office.

The eruption might only last for two to three days as it currently looks but that might change without warning since it is impossible to know for sure what is going to happen next with this eruption.

There are no good web cameras of this eruption since it is remote and started late on Friday night and the weather on Reykjanes peninsula is not good for today (20-March) or tomorrow (21-March).

Updated at 04:49 UTC. Web cameras added to this article.

Rúv – Beint vefstreymi af eldgosinu – Vogastapi
Beint vefstreymi frá eldstöðvunum – Rúv.is – New! This web camera is closest to the eruption.
Road camera 1
Live from Iceland – Keilir
Live from Iceland – Reykjanes

Article updated at 03:49 UTC. Information added. Spell check fixes.
Article updated at 04:52 UTC. Web cameras added.
Article updated at 14:44 UTC. New web camera added from Rúv.

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Update on Fagradalsfjall volcano activity on 10-March-2021

This is a short update on the activity in Fagradalsfjall volcano. This article is written at 21:08 UTC.

Since Monday 8-March-2021 there has been a lot going on and there are no signs of this activity slowing down. Currently it seems that the volcano dyke is expanding to the south and that is more into Fagradalsfjall mountain that is a earlier eruption structure from maybe few million years ago. This expansion of the magma dyke is resulting in strong earthquake activity and during the night the strongest earthquake had a magnitude of Mw5,1 at 03:15 UTC. Second largest earthquake had a magnitude of Mw4,6 at 08:50 UTC. Over the last 48 hours 68 earthquakes with magnitude above Mw3,0 have taken place. Smaller earthquakes are happening with the rate of 1 to 5 or more earthquakes at every minute. Since 24-February-2021 over 34.000 earthquakes have been recorded by Icelandic Met Office.

Dense earthquake activity on Reykjanes peninsula. Dense location of green stars that shows the location of the main active area. A lot of red dots showing smaller earthquakes
Earthquake activity on the Reykjanes peninsula. Copyright of this image belongs to Icelandic Met Office.

The chance of an eruption are increasing according to Icelandic Met Office in the news this evening. While the magma dyke has space to expand it is going to do so. The magma in the dyke is now at the shallowest only at 1 km depth or less. Exact depth has been problematic to get information about. Eruption can happen without much earthquake activity because how shallow the magma is to the top of the crust. There remains a high risk of an earthquake with magnitude Mw6,0 to Mw6,5. Both in the fracture areas on both ends of the dyke and in Brenninsteinsfjöll volcano.

Next update is going to be on Friday (12-March-2021) unless something major might happen.

Donations

Please donate if you can. Everything is still locked down with Google Adsense that doesn’t seems to have liked the traffic increase my website got when the Fagradalsfjall volcano started going active on 24-February-2021. There is nothing I can do about it since there are exactly zero person to contact with Google Adsense and I just have to hope this is somehow resolved if that is what happens (it might not because Google placed their eggs in the automation basket and that’s not a good thing). Thanks for the support. 🙂

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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.

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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)

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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.

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Katla volcano update article of 29-July-2017

This article is going to be updated as activity continues in Katla volcano today on 29-July-2017. If an eruption starts (big one) a new article is going to be written for that event.

Overview of the activity during the night and today

It seems that during the night a minor eruption took place (this is just my view). This based on harmonic tremor pulse that appeared in Katla volcano after midnight, the source of the activity seems to be north-west part of the caldera. Possibly where a magnitude 3,0 earthquake had taken place at 00:48 UTC. Harmonic tremor remains unstable and above background levels, at the moment however it seems that current harmonic tremor when this is written is due to glacier flood pushing it self from under the glacier. The water that is moving under the glacier is few hours away from (at best) from appearing in glacier rivers that come from Katla volcano.


The earthquake activity in Katla volcano during the last 48 hours. Copyright of this image belongs to Icelandic Met Office.


Harmonic tremor in Austmannsbunga in Katla volcano at 12:09 UTC. It clearly shows the minor eruption and ongoing harmonic tremor pulse. Copyright of this image belongs to Icelandic Met Office.


Harmonic tremor in Austmannsbunga in Katla volcano at 13:04 UTC. This image shows ongoing activity in the tremor. This is mostly high frequency tremor and that is interesting. What that is not known. Copyright of this image belongs to Icelandic Met Office.


Harmonic tremor in Goðabunga at 12:09 UTC. It clearly shows the night minor eruption and ongoing harmonic tremor. The harmonic tremor is however a lot less visible now on Goðabunga. Copyright of this image belongs to Icelandic Met Office.


Harmonic tremor as it appears on Rjúpnafell (SIL station). This station is at more distance from the source of the harmonic tremor pulse and shows a weaker signal as a result. The night minor eruption is also clear on this SIL station but current harmonic tremor is less visible, it does appear but at much lower level. Copyright of this image belongs to Icelandic Met Office.

Katla volcano has been moved to yellow alert. It is now possible to watch the glacier flood live from here (Rúv.is). Currently the glacier flood is getting smaller, but that might only be a temporarily thing if more water is on its way from Mýrdalsjökull glacier. There has also been a drop in conductivity for now in Múlavísk glacier river.

Announcement in English on Rúv

People advised to stay away from Múlakvísl (Rúv.is)

This article is going to be updated as needed today.

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Deep earthquake activity in Bárðarbunga volcano

Yesterday (06-September-2016) and today (07-September-2016) deep earthquake activity happened in Bárðarbunga volcano system. Most depth was at 25,9km in Trölladyngja, it is one of several deep earthquakes that have happened in that area. Few earthquakes at depth of 20,8 km took place in Bárðarbunga volcano (outside of the caldera).

160907_2120
The deep earthquakes on this image are at south-east to Bárðarbunga (in the direction of Grímsvötn, north-east of Grímsvötn) and in Trölladyngja (one blue dot). Copyright of this image belongs to Icelandic Met Office.

In Iceland earthquakes at this depth only happens due to movement of magma. Crust stresses do have effects at this depth far as I know. At the moment no magnitude 3,0 earthquakes have happened in Bárðarbunga, that might be unusual since normally after a swarm of deep earthquake few strong earthquakes happens in Bárðarbunga. That has at time of writing of this article not happened. If that happens remains to be seen. I got the feeling there might be something more in the works, but I’m going to wait and see what is going on now. At least wait for a word from Iceland Met Office about what is going on, if anything is going on at all.

All that can be done now is to wait for what happens next. (This is what geology is mostly about, endless waiting for something to happen.)

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Harmonic tremor change close to Grímsfjall volcano

There seems to be a harmonic tremor pulse or a change around Grímsfjall volcano. This might be nothing, but the change appears on several SIL stations around Vatnajökull glacier. The harmonic tremor is strongest on Húsbóndi SIL station and Jökulheimar SIL station. This might be something else then magma, glacier movement or sudden flood are an possibility.

hus.05.09.2016.at.01.29.utc
Húsbóndi SIL station. Copyright of this image belongs to Icelandic Met Office.

jok.05.09.2016.at.01.29.utc
Jökulheimar SIL station. Copyright of this image belongs to Icelandic Met Office.

Currently I don’t know what is creating this change in harmonic tremor. I know it is not weather and this is on too many SIL station to be local noise. The SIL station at Grímsfjall volcano doesn’t show any change, so everything is quiet in that volcano. But this is within Grímsfjall volcano fissure swarm that contains the volcano Þórðarhyrna, it last erupted in the year 1902 and has been quiet since (information about eruptions in Þórðarhyrna volcano can be found under Grímsfjall volcano eruption history).

If anything happens I’ll update this article or post a new one.

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Possible confirmation of minor eruption in Hamarinn volcano in July 2011

In July-2011 a minor eruption took place in Hamarinn volcano (part of Bárðarbunga volcano system). For a long time I’ve thought that those events in Hamarinn volcano where an eruption, rather than anything else. Due to how the glacier flood appeared and how sudden this all thing did happen.

Today (05-March-2016) Stöð 2 (Channel 2) ran a small news segment about this and the possible confirmation of this minor eruption in Hamarinn volcano in July-2011. I have the same view on the minor eruption in Katla volcano that same month. Its the view of Magnús Tumi, professor in geology that the events in Katla volcano where due to hydrothermal activity, not a minor eruption. I disagree with his assessment on what did happen in Katla volcano that summer. The top flood from Hamarinn volcano in July-2011 was 2.200m³/sec.

The articles I wrote about the events in Hamarinn volcano can be found here.
New harmonic tremor detected. But it is not from Katla volcano
Glacier flood confirmed from Vatnajökull glacier, flood is from Hamarinn volcano (Loki-Fögrufjöll area)

Vísir.is / Stöð 2 news in Icelandic

Lítið leynigos líklega í Vatnajökli árið 2011 (Vísir.is, Icelandic, images, video)

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Earthquake swarm in Bárðarbunga volcano (Week 03/2016)

Today (20-January-2016) at 13:05 UTC an earthquake swarm started in Bárðarbunga volcano. This earthquake swarm was not a surprise to me, since I had seen clues it would happen on 17 and 18 of January-2016 (more details later in this article). I wasn’t sure if it would happen.

160120_1915
The earthquake swarm in Bárðarbunga volcano today. Copyright of this image belongs to Iceland Met Office.

The largest earthquake in this swarm had the magnitude of 3,6 and that is a increase in magnitude from last earthquake swarm taking place at this location two weeks ago. This earthquake appears to have been created by a magma breaking rock under pressure (low frequency element present in it).

von.svd.20.01.2016.at.19.04.utc
The harmonic tremor plot from Vonarskarð SIL station, next to Bárðarbunga volcano. Copyright of this image belongs to Iceland Met Office.

I have noticed and I told Icelandic Met Office about this few days ago. There is a change in the harmonic tremor plot at 2-4Hz few days before an earthquake swarm starts in Bárðarbunga volcano. This has happened several times. Last time this happened is on 17 and 18 January-2016. Why this happens I don’t know for sure. One idea is that magma is over-pressuring once it enters the magma chamber and this might be gas release in the magma at the same time. If that is the reality, it is creating a magma foam at the top of the magma chamber that would erupt rather explosively when the pressure breaks the magma chamber currently holding it (see here, I’m not sure what this is called in science). This is only a idea that I have, but I find it the most likely explanation on what is going on in Bárðarbunga volcano. This might be wrong, but only time is going to tell what happens in Bárðarbunga volcano.

The time period between earthquake swarms is getting slightly shorter, now it’s around half a week from a whole week as was last month (December-2015). This change of phase suggests that more magma is flowing into the magma chamber and possibly in greater volume. The path the magma flows into the magma chamber is clear of all blockage, that means no earthquakes are created at that location. Current evidence suggest that only one magma chamber is being filled up with magma at the moment, but that magma chamber might be big and with some room left, but that might be quickly running out as is suggested by current earthquake swarms. The earthquake activity would be considerably higher if an eruption was about to start.

If anything more happens in Bárðarbunga volcano this week I’m going to update this article. Unless an eruption starts, then I’ll write a new one.

Update 1

A minor dyke intrusion took place in Bárðarbunga volcano caldera today (21-January-2016). The strongest earthquake in this dyke intrusion had the magnitude of 2,8 and depth of 2,5 km. This was a small and short event that took place.

160121_1735
The dyke intrusion in Bárðarbunga volcano took place in SW part of the caldera. Copyright of this image belongs to Iceland Met Office.

It’s difficult to know for sure what this means. What is clear is that magma is trying to break a path to the surface and it might have found a weak spot in the crust inside the caldera. If this starts to be a regular feature it means problems. This is the second weak spot to form in the caldera, the first one being in North-east part of the caldera, creating weekly earthquakes since September-2015.

Article updated at 01:52 UTC on 21-January-2016. Error fixed in date (it was not 10 and 11, it was 17 and 18th of January-2016).
Article updated at 20:56 UTC on 21-January-2016.