Category: Monitoring

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Look at Tungnafellsjökull volcano earthquake swarm

Here is a quick look at the earthquake swarm in Tungnafellsjökull volcano this morning. This earthquake swarm is interesting, as it started with few earthquakes at the depth of around 10 km. This suggests that magma might be pushing up to the volcano at depth now. So far this is not any high volume in my option, at least not enough to start an eruption now. But if this progress continues, it is going to end with an eruption one day. But when and how big is impossible to know at current time. for the moment the earthquakes have stopped. But it is my opinion that this a dike intrusion, not tectonic earthquakes. This can be seen how the earthquakes line them self up from 12.6 km depth and up to 3.6 km depth in almost straight line based on there location.


The earthquake swarm in Tungnafellsjökull volcano. Copyright of this picture belongs to Iceland Meteorological Office.

The earthquake swarm is dense, but that suggests an magma dike intrusion from deep within the volcano. Similar earthquakes have been seen in other volcanoes, like Esjufjöll, Askja, Katla so few are mentioned. So I know this pattern when I see it.


The earthquake pattern as it did appear on Skrokkalda SIL station. The tremor chart shows that the earthquakes where high-frequency earthquakes for most part. Something like that was seen in Eyjafjallajökull volcano before it erupted (it had earthquakes like that many years before it erupted, not just few weeks before). Copyright of this picture belongs to Iceland Meteorological Office.

I did record the largest earthquake on my geophone at Hvammstangi and at Heklubyggð. Based on that trace, the earthquake was noisy. Given me even more clues that support my suggestion that the earthquake swarm was due to dike intrusion.

Similar dike intrusion events are now taking place in Kverkfjöll volcano. But I am going to write about that tomorrow. But earthquakes in Kverkfjöll volcano have been taking place for several years now, with short and long breaks between earthquake swarms.

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Interesting earthquake activity in Tungnafellsjökull volcano

This is not the most known volcano in Iceland, it also has not erupted in the last 10.000 years at least. Normally this volcano does not have any earthquakes and it remains really quiet. Last major earthquake activity was in the year 1996 in relation to the activity in Bárðarbunga volcano and in Grímsfjall volcano that year. This volcano is named Tungnafellsjökull. It is a small volcano compared to other volcanoes in the area. During the past few days there have been several interesting earthquakes in Tungnafellsjökull volcano. They are small, around ML1.6 the largest ones. But they do have the depth of 10 to 12 km. That is what makes this earthquake activity interesting. Since this suggest that magma might be pushing into the volcano. However at this point in time, there is nothing to suggest an eruption is even close to start there. But with all long dormant volcanoes, nobody never knows what can happen next in them.


The earthquake activity in Tungnafellsjökull volcano. The volcano is located NW of Vatnajökull glacier. Copyright of this picture belongs to Iceland Meteorological Office.

Following the later earthquake today. This activity started on Skrokkalda SIL station. But this might be due to activity in Hamarinn volcano (Loki-Fögrufjöll at GVP). Not Tungnafellsjökull volcano.


The odd tremor activity on Skrokkalda SIL station. I do not yet have any explanation for this activity. Note that Skrokkalda SIL station is on top of a volcano (not on GVP list, but geological maps made in Iceland), named Skrokkalda, it also has not erupted in historical times to my knowledge. Copyright of this picture belongs to Iceland Meteorological Office.

What happens next in Tungnafellsjökull volcano is impossible to know. But it is most likely going to do what it has been doing for the past 10.000 years. A lot of nothing.

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Overview of current events in Askja volcano

The current events in Askja volcano started in Week 9 of the year 2010. Before that, Askja volcano has been showing signs of change since the year 2007 at least. In the year 2010, Week 9 a earthquake swarm was recorded by Iceland Meteorological Office. Most of the earthquakes where at around 20 km depth, and it was followed by considerable amount of harmonic tremor activity. I did know about it at the time, but I did think it would be at least 10 to 20 years until Askja volcano would not erupt. But this might have been a event in an series of event that started long time ago, without me knowing about it before (I am still checking data, it takes some time).


The earthquake activity in Askja volcano in Week 9 of the year 2010. Copyright of this picture belongs to Iceland Meteorological Office.

The image above clearly shows where magma was flowing into Askja volcano around 20 km depth. But they are to the north-east of Askja lake. The depth of this earthquakes was from 20 to 23 km.


Map of earthquake activity in Askja volcano. The green dots are earthquakes with a shallow depth, that is depth from 2 to 8 km. Yellow earthquakes have the depth of 12 to 30 km. This data is from the year 2007 at least. Copyright of this picture belongs to its owner (Janet Key).


The depth of the earthquakes in Askja volcano. Copyright of this picture belongs to its owner (Janet Key).


Depth of the earthquakes. This view shows also where the earthquakes are taking place in Askja volcano and close to it. Copyright of this picture belongs to its owner (Janet Key).

All of this map and charts are from this blog post here.


This is a heat camera image of Askja lake. Copyright of this picture belongs to Iceland Coast Guard, the image is from here.

Last year (2011) there was an dike intrusion in north part of Askja volcano. This dike intrusion was clear by a earthquakes that took place. But it stopped and has not shown any activity again in this area. As sometimes happens with dike intrusions. But this activity is an good sign that magma is now flowing into Askja volcano again. But over period of at least 10 to 20 years, it seems that magma has been flowing out of Askja volcano system. Where it has been going I have no idea. But some hypothesis suggests that it might be flowing into Krafla volcano. But there is no good data to support this hypothesis in partial.


Activity in Askja volcano in the year 2011. This activity took place on 05.05.2011 at 16:25 UTC. Copyright of this picture belongs to Iceland Meteorological Office.

At the moment there is nothing that suggest eruption is imminent. But current progress in Askja volcano is something to keep an watch on. But it is also clear that current status in Askja volcano is changing fast. So while there is nothing to suggest a eruption at the moment, it might change without warning in Askja volcano.

Pictures of Askja lake.

Askja lake 12 June 2011.
Picture of Askja lake (32 months ago according to flickr.)

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More on Askja lake sudden warming up

Few more news have appeared about the sudden warming of Askja volcano caldera lake. From what I this news say. It seems that this sudden melt of ice in Askja lake did start in beginning of March, by the end of March the lake had gone completely ice free. This is highly unusual and is not known to have happened before. This increase in hydro-thermal activity seems to be located at the bottom of the lake. But so far there is no new change around Askja lake. But it was reported yesterday that known hydro-thermal areas in Askja volcano where well active. It is now being reported that Askja lake got ice-free over period of two weeks so. But that is highly unusual and fast change in Askja lake.

Earthquake activity has not been above background level in Askja volcano so far. But this increase in hydro-thermal activity is interesting from geological point of view, and is the most clear sign that Askja volcano is preparing for a eruption. But there have been earthquakes taking place in Askja volcano. But as I sad yesterday. There have been few earthquakes in Askja volcano during past few months. Askja lake is about 1000 meters above the sea level. This means that once ice settles the lake in December it normally lasts until mid July. But the lake is self is normally up to 22C warm. So the warm increase

If anyone is going to Askja volcano. It is now official advice that people how are travelling in this area not to into Víti lake, or into Askja lake due to risk of dangerous gases that might be coming up from the ground. If you have no special reason going to Askja volcano, you should not go there at this point due to the changes in the volcano. As at this moment it is unknown what exactly is creating this changes in the Askja lake, and possibly nearby hydro-thermal areas.

University of Iceland and Iceland Meteorological Office are going to go after Easter and setup more monitoring hardware and run some test on what might be taking place in Askja volcano.

Update 1: Here is a youtube video by the user gummih that shows how fast Askja lake did thaw during middle of winter.

Icelandic news about this. Use Google translate to make sense of it.

Fylgst með framvindu mála í Öskju (mbl.is)
„Óeðlilegt ástand“ í Öskjuvatni (DV.is)
Fólk fari ekki að Öskjuvatni (mbl.is) – The news with the offical warning about going to Askja lake and Askja volcano.
Vara ferðafólk við Öskjuvatni og Víti (Rúv.is)
Almannavarnir: Ekki fara að Öskju (DV.is)
Óvenjulegt ástand við Öskju (Almannavarnir, Iceland Civil Emergency Authority)
Fólki bent á að fara ekki að Öskju (Vísir.is)

News in English about this

Photos: Iceless Iceland Volcano Lake Causes Speculation (icelandreview.com)

Blog post updated at 18:46 UTC on 04.04.2012.
Blog post updated at 19:12 UTC on 04.04.2012.
Blog post updated at 20:12 UTC on 04.04.2012.
Blog post updated at 01:28 UTC on 05.04.2012.

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Askja lake ice free during winter

It seems that Askja volcano is warming up. Literally. According to news on Morgunblaðið web site. The Askja volcano lake is now ice free. But that is highly unusual event. But normally during this time of year it is frozen over. In the news it is explained that this might be because the south wind in Iceland during the past few days, or the most likely second option. Askja volcano lake is now ice free because of more hydro-thermal activity in it. But that is seen as more likely option, as Mývatn lake, that is at considerable lower altitude is now frozen over. There was done a air survey with thermal cameras to see if there was any increased heat on the surface. So far that is not the case at the moment. But it might well be that the hydro-thermal areas under Askja lake are getting more active an warmer. At least that is the only explanation that makes logical sense to the scientists according to this news report. But while the surface activity is none. The chance is that at the bottom of the lake it is getting really hot, and that in turn warms up all the water mass in the Askja lake. But this means that the energy output from the hydro-thermal areas is already high. Even if it is not visible at the surface of the lake.

Askja lake is around 220 meters deep. It was formed in large eruption in the year 1875 (VEI=5). But that was an caldera formation event that took place. But where Askja lake is now, it used to have a mountain that was in decent high before it was blown up into the air. At current time there is no new hydro-thermal activity in Askja volcano (around the lake). Besides the one reported in Askja lake. But based on recorded history, that might change soon. But it seems that before an eruption in Askja volcano, hydro-thermal activity increases in Askja volcano. But that means new hot springs, geysers and such. With all associated dangers and smells from sulfur. At current time, there is no risk of imminent eruption. As the activity at this moment suggests this is just starting, a long more might need to happen before an eruption. But that might change without warning as always. Since all volcanoes are impossible to predict what happens in them. Askja volcano has been having slight increase in earthquake activity during past few months. That suggests new magma is flowing into Askja volcano. But that earthquake activity has somewhat stopped completely and activity has quieted down from what it was few months ago.

Update 1: Here is a new picture of Askja volcano. Taken by Ómar Ragnarsson retired news reporter from Iceland. He also has a new image from Kverkfjöll volcano here.

Update 2: Iceland Meteorological Office has issued a press release about Askja volcano. It says that Askja lake is now ice free (same as in other news). The coast guard did go to check Askja lake on 2nd April 2012 with thermal cameras. In that trip it was discovered that Askja lake is completely ice free with no floating ice in it. The known hydro-thermal areas that are known where well active according to IMO. But no new areas of hydro-thermal activity where spotted in this flight over Askja volcano. Iceland Meteorological Office is going to increase surveillance with Askja volcano and to watch for future progress on what might happen in Askja volcano in the future.

News about this in Icelandic. Use Google translate to scare the Easter Bunny.

Öskjuvatn íslaust með öllu (mbl.is)
Íslaust Öskjuvatn í mars (Vatnajökulsþjóðgarður)
Öskjuvatn íslaust (Iceland Meteorological Office)

New pictures of Askja lake are in both news. Showing it completely ice free during the winter. Pictures are taken on 18th and 27th of March. Iceland Meteorological Office has MODIS picture of Askja volcano that clearly shows how ice free Askja lake actually is.

Blog post updated at 01:32 UTC on 03.04.2012.
Blog post updated at 01:45 UTC on 03.04.2012.
Blog post updated at 16:32 UTC on 03.04.2012.
Blog post updated at 16:48 UTC on 03.04.2012.

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Minor earthquake activity in Iceland

During the past few weeks it has been quiet in Iceland. Really quiet, with almost nothing going on. It is still like that to some extent. So this is just a short overview of the small activity that has been taking place in Iceland during the past 48 hours or so.


The earthquake activity in Iceland during the past 48 hours. Copyright of this image belongs to Iceland Met Office.

The most activity in the last 48 hours have been on the Reykjanes and on TFZ. But there was an small earthquake swarm in each area. With earthquakes that did not get over ML2.5 in size so far. Two earthquakes where in Askja volcano. One in Grímsfjall volcano fissure system (maybe in Þórðarhyrna volcano).


Earthquake west of Hekla volcano, in the SISZ. This picture is released under Creative Common Licencee. See the licence page for more detail.

Katla volcano

During this winter. Katla volcano has been quiet. This is somewhat normal, as more snow means more ice-mass on top of the volcano. But now that has started to melt a little and that means less ice-mass on top of the volcano. That could mean more activity in Katla volcnao during the next few weeks. So far however the activity remains small and there are no special earthquakes to report.


Earthquake activity in Katla volcano, on this picture earthquake activity west of Hekla volcano can also been seen here. Copyright of this image belongs to Iceland Met Office.

The earthquakes west of Hekla volcano belong to the SISZ fault area. Not Hekla volcano it self. What is also interesting is the earthquake activity in south part of Katla volcano. In area outside of the glacier. This are small earthquakes, that do not appear on my geophone. Even if they are close to it. I am unsure what this means for the future. But it is worth keeping an eye on it.

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Grímsfjall volcano continues to prepare for a new eruption

As I did mention in a blog post from 16. January 2012. Grímsfjall volcano is preparing for a new eruption. That progress has not slowed down at all. I am rather sure that the eruption prepare progress in Grímsfjall volcano has sped up. But this is nothing confirmed at the moment. I am just noticing slow increase in earthquakes from Grímsfjall volcano.


Today’s activity in Grímsfjall volcano. Copyright of this picture belongs to Iceland Met Office.


Grímsfjall volcano activity in Week 11 2012. Copyright of this picture belongs to Iceland Met Office.


Grímsfjall volcano activity in Week 12 2012. Copyright of this picture belongs to Iceland Met Office.

It is impossible to know for sure when next eruption starts in Grímsfjall volcano. But at the current time, the clock is ticking down faster then it did before in my opinion. As is known from history. Grímsfjall volcano has erupted sometimes the year after. Even after a big eruption. As was the case last year (2011), when it had the largest eruption in 140 years.

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Minor earthquake activity in Iceland

There isn’t a lot taking place in Iceland at the moment. This is somewhat down to stormy weather in Iceland during the past few days and weeks. As strong storms reduce the sensitive of the Iceland Meteorological Office SIL network.


Quiet Iceland. Copyright of this picture belongs to Iceland Met Office.

Activity in Iceland happens in jumps. Between high activity episodes there are long episodes of low to none activity at all in Iceland. This period of low activity are different in length. Some can last for few weeks. While others can last for many years and up to thousands of years.

Global activity

Global earthquake activity is slow this days. Few earthquakes over Mw6.0 in size. The activity for earthquakes smaller then Mw6.0 in size is about the same as normally. Volcano activity seems to be about normal. But it is hard to know that for sure as reports appear late on global volcano activity.

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More earthquakes should be expected on the Reykjanes

The earthquake swarm on the Reykjanes has slowed down considerable since it did start yesterday. But it is still ongoing in my opinion. Even if there are no earthquakes currently taking place at the moment. There are several reasons for this. The biggest one is that this area seems to be getting more active now then it has been for many decades now. The fissure that is currently moving is connected to Krýsuvík volcano, but this was reported in the news. I do not know every fault line in this area and how they are connected (plus, my volcano map is in an box until I move back to Denmark) together. But I do know that

During the past 2 to 3 years the volcano Krísuvík has been showing more activity. With inflation and deflation episodes that lasts from few days to weeks at the time. Followed by an earthquake swarms both before and after each episode of activity. This activity seems to be increasing, at least that is my opinion on what is happening at the moment.

While this earthquake swarm is still ongoing. It might have long periods of no activity at all. This is common for faults that have not moved in an long time. As seems to be the case in Helgafell mountain and nearby area. But the fault lies close to that mountain or under it (I am not sure). But this started this year with an magnitude ML3.2 earthquake in this area earlier this year.

It is hard to know exactly when next episode of this activity is going to continue. But I am sure that it is going to be soon.

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Earthquakes in north and south Iceland [Updated]

This evening has been busy in Iceland. There was an ML3.5 earthquake just outside an area called Gjögurtá (part of TFZ). Followed by an ML3.2 aftershock. Earthquake activity seems to have stopped there for the moment. This took place at 22:06 UTC on 29.02.2012. The largest earthquake was felt over an large area that was closest to its location.


The location of the earthquake in the TFZ. Copyright of this picture belongs to IMO.

At 00:29 UTC on 01.03.2012 there was an earthquake on the Reykjanes. It happened in an mountain called Helgafell. Early results suggest that this earthquake had the size of ML3.2. It was felt over an wide area in south Iceland. Aftershocks are currently taking place, and more large earthquakes in this area cannot be ruled out at the moment.


The earthquake location on the Reykjanes. Copyright of this picture belongs to IMO.

There is an chance for more earthquakes in Reykjanes. As earthquake swarms in this area of Iceland can often be tense and make many earthquakes that have magnitude 3.0 and stronger.

This earthquake activity appears clearly on my geophones in Iceland. They can be viewed here and are updated every 5 min.

Update 1: More strong earthquake activity is taking place on the Reykjanes at this moment. The largest earthquake so far is ML3.9 according to the automatic data from IMO.

Update 2: Here is the image from Iceland Met Office of the area where this earthquake activity is taking place.


The current earthquake activity on the Reykjanes. Copyright of this picture belongs to IMO.

Update 3: The size of the second earthquake has been upgraded to ML4.2. Some minor damage has already been reported according to new from Rúv.

Blog post updated at 01:14 UTC on 01.03.2012.
Blog post updated at 01:39 UTC on 01.03.2012.
Blog post updated at 01:52 UTC on 01.03.2012.

Icelandi News about the earthquake in north Iceland. All news are in Icelandic.

Jarðskjálfti upp á 3,5 út af Gjögurtá (mbl.is)
Snarpir skjálftar fyrir norðan (Vísir.is)
Skjálfti út af Eyjafirði (Rúv.is)

News about the earthquake on the Reykjanes. All news are in Icelandic.

Skjálftakippur á höfuðborgarsvæðinu (Rúv.is)
Jarðskjálfti fannst vel á höfuðborgarsvæðinu (Vísir.is)
Jarðskjálfti við Helgafell (mbl.is)