Category: Katla / Mýrdalsjökull

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Update on Katla volcano earthquake swarm

There has not a lot changed in the past few hours since the earthquake swarm did start in Katla volcano. Eruption has not yet started in Katla volcano and when it might start is still a mistery.

Current map of the earthquake activity.


Current earthquake activity in Katla volcano. Copyright of this picture belongs to Iceland Met Office.

Here are traces from my Heklubyggð geophone. But that is currently the geophone that I have that is closest to Katla volcano. I am collecting donations so I can buy two new geophones. The blog post about that can be found here. I do not expect to have the geophone in place before a eruption starts in Katla volcano this time around. So far the donations are up too 5,410.74 DKK, so I am not far from what I need to collect. I do not have to pay customs of this according to a email I got from the customs office when I did ask about it. But I have too pay 25,5% VAT on this when it gets here. That might be a good amount I think in Icelandic Kronas (ISK).


One of the large earthquakes. This is not the strongest earthquake in the earthquake swarm that took place this morning in Katla volcano. This is also a double earthquake, that is two earthquakes taking place at the almost the same time. That is the reason for the odd looking wave form on this earthquake trace. This picture is released under Creative Commons licence. See Licence web page for more details.


A ML3.0 earthquake that took place in Katla volcano this morning. This picture is released under Creative Commons licence. See Licence web page for more details.


The largest earthquake in the earthquake swarm this morning. Its size was ML3.55 with the depth just short of 1 km. This picture is released under Creative Commons licence. See Licence web page for more details.


A ML2.94 earthquake in Katla volcano this morning. This picture is released under Creative Commons licence. See Licence web page for more details.

So far it has quieted down in Katla volcano. But that does not mean a lot. As magma can go on the move at any time. Without any warning at all. So monitoring Katla volcano is important with that fact in mind. According to Iceland Met Office, this is the largest earthquake swarm in Katla volcano caldera since the year 2002.

I am expecting more strong earthquakes to take place in Katla volcano. But it is impossible to know when a new earthquake swarm might start in Katla volcano and how large and long it is going to last. For the moment, it is just wait and see.

Iceland Met Office has put up a news about this in English. Thanks too the readers how pointed this out!

Earthquake activity in Katla volcano October 2011

Icelandic News about this earthquake swarm.

Snarpasta hrinan í Kötlu frá 2002 (Rúv.is, Icelandic)
Snörp hrina í Mýrdalsjökli í nótt (Rúv.is, Icelandic)
Snörp hrina í Kötlu (Vísir.is, Icelandic)
Sterkir skjálftar undir Mýrdalsjökli (mbl.is, Icelandic)
Um 20 skjálftar yfir 2 stig (mbl.is, Icelandic)

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Large earthquake swarm in Katla volcano

At 02:45 UTC a large earthquake swarm did start in Katla volcano. I do not know if this an start of a eruption in Katla volcano or not. For the moment it is too early to know for sure. I have to wait few more min before that becomes clear on the harmonic tremor plots. The largest earthquake so far according to the automatic SIL systems is a ML3.9 earthquake.


The earthquake swarm in Katla volcano. The second green star is from a fake ML3.3 earthquake from yesterday. Copyright of this picture belongs to Iceland Met Office.


The harmonic tremor plot on Slysaalda SIL station at 03:04 UTC on 5 Október 2011. Copyright of this picture belongs to Iceland Met Office.

It takes a few moments to become clear if Katla volcano is starting a eruption or not. I am going to post updates as this situation changes if I have too.

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Small eruption took place in Katla volcano in July 2011

According to the news on Rúv this evening it is now a opinion at Icelandic Met Office that a small eruption did take place in Katla volcano during the days 8 and 9 July 2011. This eruption was however larger then the eruption in Fimmvörðuháls in Eyjafjallajökull volcano last year (2010). But this is based on tremor data from around Katla volcano during this summer. But this is what Einar Kjartansson geologist at Iceland Met Office says in the news at Rúv this evening. Even if this small eruption did take place in Katla volcano it does not seems to have eased the pressure inside Katla volcano, so a large eruption in Katla volcano is still a possibility in the close future. Note: GVP has updated Katla volcano eruption status to the year 2011!

This conclusion was reached by checking out the cauldron that formed during this event. But they show a sign that they had a sudden melt taking place. But that melt can only happen of lava got into contact with the ice and fast melted it. This is also the reason why there was a 5 meters flood in Múlakvísl glacier river that did destroy the bride over it. But it is also a fact that the harmonic tremor in Katla volcano during this period was the same as that did happen during the eruption in Eyjafjallajökull volcano. The only difference was that it it was stronger from Katla volcano then in Eyjafjallajökull volcano it seems (at least from what I can see from the data). Even if it lasted for a shorter time then in Eyjafjallajökull volcano.


The tremor on Slysaalda SIL station on 9 July 2011 at 00:36 UTC. Copyright of this picture belongs to Iceland Met Office.


Alftagrof SIL station on 9 July 2011 at 00:36 UTC. Copyright of this picture belongs to Iceland Met Office.


The area that was active and had a eruption on 8 and 9 July 2011. Copyright of this picture belongs to Iceland Met Office.

Even with this small eruption it is clear that Katla volcano is not done with its eruptions. Since the large one is not yet over. When that happens is a good question and nobody has a answer too at the moment.

Note: This is also what did happen in Hamarinn volcano the week after. But I also think that volcano did have a minor eruption in July 2011. As the signatures are the same from what I can gather. So that makes three eruptions in Iceland for the year 2011 if confirmed later on.

Icelandic News with this. Use Google translate with care on it. Since it does not understand.

Allt bendir til Kötlugoss (Rúv.is, Icelandic, Picture)
Segir Kötlu hafa gosið í sumar (DV.is, Icelandic, Picture)
Lítið eldgos í Kötlu í sumar (mbl.is, Icelandic)

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Earthquakes in Katla volcano, strong sulphur smell in Múlakvísl river before the earthquake happened

This morning there has been some earthquake activity in Katla volcano. But it has also been reported in the news this morning that a really strong sulphur smell was found around 06:00 UTC on nearby farm to Múlakvísl river this morning. But this was before the earthquake did happen. I am not sure if this sulphur smell continues to be felt in the area close to Katla volcano. No changes in water hight has been detected in Múlakvísl glacier river.

The ML2.6 earthquake in Katla volcano was on 2.3 km depth. This was mostly a dike intrusion into the bedrock of the Katla volcano caldera.


The earthquake swarm this morning in Katla volcano. Copyright of this picture belongs to Iceland Met Office.


High resolution of the Katla volcano earthquake this morning. Along with correct depth and size. This picture is released under Creative Commons licence. See Licence page for more details.

As before. This is just a wait and see what is going to happen in Katla volcano as before.

Icelandic News of the sulphur smell in Múlakvísl glacier river.

Brennisteinslykt fannst við Múlakvísl í morgun (Vísir.is, Icelandic)
Brennisteinslykt við Múlakvísl (mbl.is, Icelandic)

Update 1: According the news on Rúv this activity suggests that hydrothermal activity is continuing to increase in Katla volcano caldera. But the news also says that this activity is something like that did happen from the year 2002 to the year 2004, when hydrothermal activity did increase before it started to get lower again. It is also pointed out my Matthew Roberts that Múlakvísl glacier river is sensitive to changes in Mýrdalsjökull glacier and small floods can happen without any warning in it due to increased hydrothermal activity.

Rúv news in Icelandic about this.

Bendir til aukinnar jarðhitavirkni (Rúv.is, Icelandic)

Blog post updated at 13:07 UTC, 23 September 2011.

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New earthquake swarm in Katla volcano

After few quiet days in Katla volcano. It seems that new earthquake swarm is about to start in it. But this earthquake swarm did start with a ML2.8 earthquake (automatic size) at 10:55 UTC. This earthquake have been followed by smaller earthquakes. So far there have not been many earthquakes in this earthquake swarm. But the largest earthquake took place on what I think is the fissure where the eruption in the year 1918 took place.


The earthquake swarm can be seen here. Copyright of this picture belongs to Iceland Met Office.

The largest earthquake clearly has magma signature in my opinion. As it can be seen on my geophone recording of this earthquake.


The ML2.8 earthquake. This picture is released under Creative Commons Licence. Please see licence web page for more details.


High resolution of the Katla volcano ML2.8 earthquake. The bump later on this earthquake trace is the second earthquake that only had the size ML0.9 according to the automatic size estimate. This picture is released under Creative Commons Licence. Please see licence web page for more details.

There seems to have been some type of tremor event on Goðabunga SIL station just before the earthquake. I am not sure what event this was. But it does not appear on other SIL stations around Katla volcano.


Goðabunga SIL station. Copyright of this picture belongs to Iceland Met Office.

For the moment the only thing that can be done is to wait and see what happens in Katla volcano.

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More new tremor spikes in Katla volcano

Yesterday and today there where two tremor spikes in Katla volcano. This follows a higher then normal background noise that I cannot directly trace only to wind as I did first think. What is going on is not clear, but it remains a bit of events just before the July 1999 minor eruption (suspected). But it has been speculated by scientist that event was related to inflation event deep inside Katla volcano systems. But the actual fact remains unclear. More information on the event in July 1999 can be read here (in Icelandic).

Pictures from the year 1999 of the harmonic tremor event in July that year.


The harmonic tremor spikes in July 1999 in Katla volcano. Copyright of this picture belongs to Iceland Met Office.

There was also special note on this tremor chart here from skh SIL station (now gone). But in the year 1999 this signal was most clear on Snæbýli SIL (snb). But today this signal appears to be most clear on Goðabunga SIL station and Eystri-Skógar SIL (esk) SIL station. I do not know what the difference is. But it clearly is something.


The harmonic tremor spikes in July 1999 in Katla volcano. Copyright of this picture belongs to Iceland Met Office.


The harmonic tremor spikes in July 1999 in Katla volcano. Copyright of this picture belongs to Iceland Met Office.

Please note that all earthquakes have been cleared from this old SIL tremor plots.

Current day activity in Katla volcano looks like this on the SIL stations where it is most clearly seen.


Odd spikes can be seen here on this tremor plot. I do not know what they are. Copyright of this picture belongs to Iceland Met Office.


Hard to see spikes can be seen on Goðabunga SIL station. They are the same as from Eystri-Skógar SIL station. Copyright of this picture belongs to Iceland Met Office.


Same as above. But stronger then on Goðabunga SIL station. Copyright of this picture belongs to Iceland Met Office.

It is hard to know for sure what this signals means. But I am sure that this signals are going to mean something someday. But when is hard to know.

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Two earthquake swarms during the night.

During the night there where two earthquake swarms in Iceland. One of this earthquake swarms was man made.

The larger earthquake swarm was in Hengill volcano and was man made. It happens and the hydrothermal plant pumps down cold water into the bedrock and changes the pressure and strain in the bedrock and nearby sediments that make up this area. The earthquakes only happens when cold water is being pumped down into the ground. When they are not pumping cold water into the ground, no earthquakes happens. Largest earthquakes in this man made earthquake swarm where ML2.5 and ML2.2 according to automatic measurements of Iceland Met Office. But most of the earthquakes where less then ML1.0 in size.


The man made earthquake swarm in Hengill volcano. Copyright of this picture belongs to Iceland Met Office.

The second earthquake swarm that did happen during the night was in Katla volcano. This earthquake swarm is no surprise to people how have been watching Katla volcano activity since July. This earthquake swarm in Katla volcano was however small during the night. But there did more earthquake activity in Katla volcano around 18:00 UTC yesterday. But overall it seems that Katla volcano has slowed down a bit compared to last few days.


Earthquakes in Katla volcano during the past 48 hours. Copyright of this picture belongs to Iceland Met Office.

For the moment it is rather quiet in Iceland, as there is currently not that much activity in Katla volcano. But that can change without any warning at all. As Iceland is highly active in both volcanoes and earthquakes.

Icelandic news about the earthquake activity in Hengill volcano.

Jarðskjálftar í boði Orkuveitunnar (Rúv.is, Icelandic)
Jarðskjálfti á Hellisheiði (Vísir.is, Icelandic)

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New earthquake swarm in Katla volcano during the day

Today there was a new earthquake swarm in Katla volcano. This earthquake swarm was in the caldera of Katla volcano, same as the earthquake swarms that have happened inside Katla volcano since July, when this pattern of activity did start.


Current earthquake activity in Katla volcano. Copyright of this picture belongs to Iceland Met Office.

It has been few hours since the earthquake activity did stop in Katla volcano. If the pattern that has been ongoing for the past week and longer there should be a harmonic tremor spike in few hours time. But that it currently hard to know if this pattern is going to hold up or not. But I have every reason to believe that it is going to do so. For the moment, all that can be done is to wait and see what happens next in Katla volcano. At the moment, I have not seen any harmonic tremor spike during the day or at current time when this blog post is written.

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More harmonic tremors in Katla volcano

It seems that Katla volcano is not as quiet it seems to be. For the moment the harmonic tremor seems to be small and only properly observable on one SIL station due to how weak it is at current time. So far two harmonic spikes have happened. This is most likely a hydrothermal system going crazy under the glacier close to Lágu Hvolar SIL station, rather then magma on the move (or at least that is what I think).


Harmonic tremor at Lágu Hvolar SIL station. The harmonic tremor can be seen at the end of this tremor plot. Copyright of this picture belongs to Iceland Met Office.

There has not been a lot of earthquake activity in Katla volcano during the last 24 hours or so. But that might not mean anything, as eruption can and have started without any warning at all (example: Grímsvötn volcano May 2011). So for now, it is more wait and see and more waiting it seems.