Category: Dyke intrusions

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Deep earthquake swarm in Tungafellsjökull volcano

Today (03.03.2013) between 13:19 UTC and to 13:21 UTC a deep earthquake swarm took place in a volcano named Tungnafellsjökull. This was a minor earthquake swarm, with the largest earthquake having magnitude 1.4. But it is the depth that is important here. The depth was most at 28 km, with the shallowest earthquake having the depth 18.7 km. This suggest magma intrusion into the volcano at depth. A pattern that was seen during the Eyjafjallajökull volcano eruption as an example.

For the past few months. Tungnafellsjökull volcano has been having swarms of earthquakes. All of them small, but many of them above 2.0 in magnitude. But so far none above magnitude 3.0. While earthquake activity has remained low in Tungnafellsjökull volcano I find that events are speeding up there in the past few months. With the terms that more earthquakes are being detected in this volcano and now at more depth. I find this worrying and also interesting. This volcano is far from any populated area, so any damage resulting for an eruption in it should be minimal. It also has no glacier to speak of. There is going to be a bad weather in Iceland until Friday (according to the weather forecast at the moment), so detecting any small earthquakes in this area might be limited by it.

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The red dots show the earthquake activity in Tungnafellsjökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

It is too early to know what happens in Tungafellsjökull volcano. It is also important to note that Tungnafelljökull volcano has never erupted in historical times. This makes figuring out what happens next in it more difficult then ever. This activity might not mean an eruption is imminent. But at the moment I cannot rule one out just yet. It is clear that more activity is going to be needed before the picture of what is taking place in Tungnafellsjökull volcano gets clearer.

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Magnitude 3.8 earthquake in Bárðarbunga volcano

During the night at 04:50 UTC there was an earthquake with the magnitude 3.8 in Bárðarbunga volcano. This appears to be a minor dike intrusions into Bárðarbunga volcano. This happens regularly in Bárðarbunga volcano. Often resulting in a lot larger earthquakes then current earthquake swarm that is taking place in Bárðarbunga volcano.


Earthquake activity in Bárðarbunga volcano. The star is the magnitude 3.8 earthquake. Copyright of this image belongs to Icelandic Meteorological Office.

It is impossible to know what is going on in Bárðarbunga volcano. But there is no risk for volcano eruption for now. Even if there is possibility of minor dike intrusion taking place in Bárðarbunga volcano at the moment. I am not expecting anything more at the moment. But more earthquakes can not be ruled out, as Bárðarbunga volcano is a earthquake active volcano.

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Earthquake swarm north of Kolbeinsey Island

During the night (on 15.12.2012) there was a swarm of earthquakes far north of Kolbeinsey Island. The distance from Kolbeinsey Island is about 100 to 200 km. What exactly is taking place at this location is impossible to know for now. Since this is far from Iceland and the SIL network. Last eruption is believed to have taken place around this area back in the year 1999, or at least there was an large dike intrusion at that time. What did happen exactly is not known.


The earthquake activity north of Kolbeinsey Island at midnight (00:00 UTC) 15.12.2012. Copyright of this image belongs to Icelandic Meteorological Office.


Earthquake activity at 09:00 UTC this morning (15.12.2012). More earthquakes have taken place since midnight. Copyright of this image belongs to Icelandic Meteorological Office.

There is a chance of more earthquakes in this area. It can also be expected that not all earthquake activity in this area is being detected by the SIL network. Due to distance, weather and ocean activity.

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Dike intrusion in Askja volcano

Today (14.12.2012) around 12:00 UTC Askja volcano had dike intrusion. This dike intrusion was not in the main volcano it self. But a good distance away from it. But this is in a area that has erupted before in distant past in a fissure style eruption (just lava, no volcano ash). What is the case now I am not sure at the moment. But this dike intrusion was at the depth of 25 to 22 km. So it has long way to go before any eruption takes place. This dike intrusion did also not show any sign of moving upwards according to Rúv News of this event.


Earthquake map from IMO showing the dike intrusion clearly. Copyright of this image belongs to Icelandic Meteorological Office.

What this means in the long term is impossible to know at this point. But this is one event in a long series of events that started in March 2010. This is going to end with a eruption. Large or small is impossible to know until it happens. What is also impossible to know is when and where such eruption might take place. As is always the case with active volcanoes. There is at least no reason to panic about this. Not now, not ever.

Donations: I am still needing donations to cover my cost of buying 3G hardware for upcoming geophone stations Böðvarshólar (total cost around 1300 DKK, or 29900 ISK). I have got some donations already. But they just cover the cost of UPS and USB card for Skeiðflöt geophone station. But I was fixing technical problems with it. Thanks for the support.

Icelandic News about this

Á annan tug skjálfta austur af Öskju (Rúv.is)

Blog post updated at 23:29 UTC on 14.12.2012

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Earthquake activity update on 16.11.2012

Here is a short update on earthquake activity in Iceland. It has been stormy few weeks so recorded earthquake activity has not been a lot in Iceland.

Tjörnes Fracture Zone

Earthquake activity continues in TFZ. A bit less then when it did start on 20. October 2012. But it still moves along. The risk of large earthquake area remains for this area. When, where and how big remains unknown factors so far.


Earthquake activity in TFZ. Copyright of this image belongs to Icelandic Meteorological Office.

Herðubreiðarfjöll volcano

Herðubreiðarfjöll volcano is a small volcano (no GVP entry that I know of) just north of Askja volcano. But Herðubreiðarfjöll volcano are in fact part of Askja volcano fissure swarm. But I do not think they are part of Askja volcano as such.


Earthquake activity in Herðarbreiðarfjöll volcano (the blue dots). Copyright of this image belongs to Icelandic Meteorological Office.

The earthquake activity in Herðurbreiðarfjöll volcano was most likely a minor dike intrusion into the volcano. What that means is too early to say at this moment. But most likely it does not mean anything for now at least.

There has been some minor ice-quake activity in Iceland when the temperature drops below 0 degrees in Iceland.

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Earthquake swarm update for TFZ and Kverkfjöll volcano at 12:55 UTC

Earthquake swarm in TFZ continues. But earthquake activity continues to drop at fast rate. The largest earthquake so far from midnight has the magnitude of 4.0 (reviewed magnitude). Several smaller earthquakes have taken place during the night in TFZ. But no larger earthquakes have so far taken since midnight. Current earthquake activity has moved little bit east since it started on 21.10.2012.


Current earthquake activity in TFZ for the past few months. Copyright of this image belongs to Icelandic Meteorological Office.

Kverkfjöll volcano

Earthquake activity has continues since it started again in Kverkfjöll volcano. The strongest earthquake so far had the magnitude 3.3. This earthquake activity in Kverkfjöll volcano has it source in magma movements inside Kverkfjöll volcano. This is most likely not going to start an eruption. But it is worth keeping an eye on.


Earthquake activity in Kverkfjöll volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Earthquake activity has been slow in Kverkfjöll volcano. This is normal. As this is not tectonic movements, as in TFZ. But magma often moves slower and makes fewer earthquakes then just pure tectonic movements.

Blog post updated at 14:06 UTC on 23.10.2012
Blog post updated at 14:14 UTC on 23.10.2012

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New earthquake swarm in Kverkfjöll volcano

It seems that earthquake activity has started again in Kverkfjöll volcano. So far this is just small earthquakes. But earthquake activity started in Kverkfjöll volcano on 20.10.2012. That was also just small earthquakes. This is most likely minor dike intrusion taking place in Kverkfjöll volcano.


Earthquake in Kverkfjöll volcano. Copyright of this image belongs to Icelandic Meteorological Office.

It is impossible to know what this activity means. But I do think it is going to remain as is for now. At least it is unlikely for the time being that something bigger is going to happen in Kverkfjöll volcano. But it is worth keeping an eye on this activity. As this might be a clue that Kverkfjöll volcano are waking up from there dormancy. But it might just be minor earthquake activity that happens occasionally in volcanoes, without any other activity taking place in them following such activity.

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Earthquake activity update on 20.10.2012 at 14:51 UTC

Today (20.10.2012) has been busy in terms of earthquake activity in Iceland. So I am expecting to write a second update later today on this activity.

Hekla volcano

At 05:28 UTC there was an earthquake in Hekla volcano. This earthquake had the magnitude of ML1.1 with the depth of 0.6 km. No other earthquakes have followed this single earthquake. What this means is impossible to know at this time. But so far everything remains quiet in Hekla volcano.


Earthquake in Hekla volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Kverkfjöll volcano

Earthquake activity continues in Kverkfjöll volcano. This earthquake activity is the result of dike intrusion into Kverkfjöll volcano. So far this earthquake activity is taking place in short burst of earthquake swarm.


Earthquake activity in Kverkfjöll volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Tjörnes Fracture Zone

At 02:07 UTC earthquake activity did start in TFZ. Just off the coast of Iceland. This earthquake activity is taking place in area that last had earthquake swarm in September. I did cover that earthquake activity in details on this blog. So far the largest earthquakes in this area of TFZ have had the magnitude of ML2.9. This is purely tectonic earthquake activity.

Earthquake activity in TFZ. Copyright of this image belongs to Icelandic Meteorological Office.

It is difficult to know what happens next in TFZ earthquake activity. But it likely going to continue for the next few hours to days like earlier. It is best to keep an eye on this earthquake activity. This earthquake activity also sometimes stops for few hours before it continues again. Most of this earthquake activity can be seen on my geophone network web page.

If anything major happens in this earthquake activity. I am going to post new blog post with updated information on that activity.

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Earthquake swarm in Kverkfjöll volcano

At 20:03 UTC an earthquake swarm started in Kverkfjöll volcano. The strongest earthquake so far has the magnitude of ML2.6, the depth is 1.1 km according to automatic estimate. Both size and depth of this earthquake are expected to change once it has been reviewed by Icelandic Meteorological Office. So far no harmonic tremor has been detected following this earthquake swarm. The most likely explanation for this earthquake swarm is that dike intrusion of magma has started in Kverkfjöll volcano. This has been happening on regular basis now for several years.


The swarm in Kverkfjöll volcano. Copyright of this image belongs to Icelandic Meteorological Office.

The earthquake swarm is currently ongoing. It is hard to know what happens in Kverkfjöll volcano following this earthquake swarm. But Kverkfjöll volcano are among Iceland most active volcanoes. With last eruption being in the year 1968 (small I think). This is clearly magma on the move inside Kverkfjöll volcano. But I do not know if this is going to result in a eruption or not. At the moment. It is my estimate that eruption is unlikely to happen. But that might change without warning at any time. But changes in Kverkfjöll volcano might be rapid and without warning. I am going to continue to monitor this activity and post new blog post if there are any major changes in activity in Kverkfjöll volcano.

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Weak harmonic tremor pulse from Hamarinn volcano

Since around 19:00 UTC (16.10.2012) a harmonic tremor pulse has been taking place in Hamarinn volcano (Bárðarbunga volcano). There is in my view no eruption taking place at the moment. This is most likely a dike intrusion of magma somewhere in the area of Hamarinn volcano. That might however trigger an eruption. But we just need to wait and see on that for the time being. This activity is interesting, as there was a small eruption in this area in July 2011.


The harmonic tremor pulse is strongest on this SIL station. But it is weak regardless. The signal suggest this event is taking place close to this SIL station location. Copyright of this image belongs to Icelandic Meteorological Office.


The harmonic tremor pulse also appears on Skrokkalda SIL station. But is weak and can hardly be detected on it. Copyright of this image belongs to Icelandic Meteorological Office.

The harmonic tremor pulse can be seen at the end of the above SIL station traces. The harmonic tremor pulse is higher then normal background noise (wind, ocean waves, human traffic, etc) on the SIL station. I do not expect this to be noise. The signal is too strong for that. It also hard to travel in this part of Iceland in October due to bad weather and difficult conditions in the high areas of Iceland.