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New harmonic tremors spikes in Katla volcano

This has become almost a daily occurrence. But today there was one harmonic tremor spike (at least) in Katla volcano. It is unclear why this harmonic tremor spikes happen in Katla volcano. But they often do happen just before a earthquake swarm starts, but often several hours before (sometimes). I am not sure why that is. But one idea is that this activity is connected to hydrothermal areas that are under the Mýrdalsjökull glacier.

Earthquake activity has been quiet in Katla volcano today. But it is hard to know for sure if that is going to last. As earthquake activity appears to be on the rise in Katla volcano during the whole of the year 2011 according to news in Iceland (see earlier blog post for details).


Harmonic tremor spike as seen on Lágu Hvolar SIL station. The spike is between 04/09 and 05/09. The spike is a small top in the tremor chart (hard to spot). Copyright of this picture belongs to Iceland Met Office.


Harmonic tremor spike as seen on Snæbýli SIL station. The spike is between 04/09 and 05/09. The spike is the broad band that suddenly appears in the tremor data. It is easier to see then on Lágu Hvolar. Please note that it seems that Snæbýli SIL station has gone offline again, as it has stopped updating. Copyright of this picture belongs to Iceland Met Office.

It is clear that Katla volcano is going for a eruption. But the question remains is just when that is going to be, but it is impossible to predict when a eruption is going to take place in Katla volcano. But the signs have come clear in my opinion in this matter. For the moment it is just waiting and watching. But this might be a long wait until something happens in Katla volcano.

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Increased earthquake activity in Katla volcano during the past year

In todays news at Rúv News there was a report about Katla volcano. This news has a interview with a Einar Kjartansson geologist at Iceland Met Office about the earthquake activity in Katla volcano. Einar speaks about the earthquake activity in Katla volcano yesterday (3. September 2011). But he also speaks about how activity in Katla volcano has been increasing during this year and it is more then it is normal in Katla volcano. But it is important fact that Katla volcano always has earthquake actvitiy, even with earthquakes up to ML4.5.

He also says that this increased earthquake activity in Katla volcano is due to dike intrusion into Katla volcano or some other activity that is currently taking place in Katla volcano.

Flood in Múlakvísl glacier river

During yesterday and during the night there was a glacier flood in Múlakvísl glacier river. This time around it was not connected to the activity in Katla volcano. But due to heavy rain in this area and melting of the glacier in the heat that has been in Iceland for the past few days. Since then the flood has subsided and Múlakvísl glacier river is back to normal and the flood has subsided.

News about all this.

Aukin skjálftavirkni í Kötlu (Rúv.is, Icelandic)
Braut niður varnargarð (mbl.is, Icelandic)
Miklir vatnavextir í Múlakvísl (Vísir.is, Icelandic)

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Earthquake swarm in Katla volcano

Today (3. September 2011) at 16:45 UTC a earthquake swarm did start in Katla volcano. So far this earthquake swarm has been small, with the largest earthquake just with the size ML2.7 at the depth of 1.1 km (automatic data). But the quality of this earthquake was good, so location is accurate from what I can tell.

I am not sure at this moment if there is a harmonic tremor spike following this earthquake swarm or not. As the earthquakes are long period due the fact that they are created by magma movement in Katla volcano. This might be dike intrusion. But for the moment it is hard to know that for sure.


The area of earthquake activity today in Katla volcano. Copyright of this picture belongs to Iceland Met Office.


The ML2.7 earthquake (automatic size) in Katla volcano caldera. This picture is released under Creative Commons Licence, see Licence web page for more details.


Harmonic tremor plot of the current activity. Latest activity is at the end of the tremor plot. Copyright of this picture belongs to Iceland Met Office.


Harmonic tremor plot of the current activity. Latest activity is at the end of the tremor plot. Copyright of this picture belongs to Iceland Met Office.


Harmonic tremor plot of the current activity. Latest activity is at the end of the tremor plot. Copyright of this picture belongs to Iceland Met Office.

I cannot tell at the moment what is going on in Katla volcano. But the earthquakes tell me that the reason why they are happening is because of magma is moving inside Katla volcano. But latest data (not shown here) do however show that no harmonic tremor is currently ongoing, if it ever started during this earthquake swarm. I am expecting the earthquake swarm to continue and last for the next few hours. But I must point out that that is what might happen, as sometimes earthquake swarms just stop when you think that they might be about to start for real.

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Inflation starts in Katla volcano

There seems to be inflation going on in Katla volcano, at least according to the automatic GPS data that IMO has on it’s web site. But this might be error in the data. But for the moment I do not think it is. But please do look at this data with the view that it might be wrong.


The inflation appears clearly on Lágu Hvolar GPS station. Copyright of this image belongs to Iceland Met Office.

The inflation can be seen on Lágu Hvolar and Sólheimaheiði GPS stations. But it appears to be more clear at HVOL GPS station. But that is most likey because that GPS station is closer to the magma pocket in question that creates this movement.


The inflation also appears on Sólheimaheiði GPS station. But not as clearly as on Lágu Hvolar GPS station. Copyright of this image belongs to Iceland Met Office.

What might be the critical inflation before a eruption starts is hard to know until it happens. For Eyjafjallajökull volcano that was 60mm, for Grímsfjall volcano the inflation was actually 350mm. But that volcano had eruptions that did not change it’s inflation numbers. I do not know why Grímsfjall volcano is so different in this respect from other volcanoes in Iceland (that I know of so far).

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A ML3.2 earthquake (automatic size) happens in Katla volcano caldera

At 18:44 UTC a earthquake with the size ML3.2 and the depth of 2.9 km did happen in Katla volcano caldera (this size is based on automatic data and is going to be subject to a change).


The ML3.2 earthquake in Katla volcano. Copyright of this picture belongs to Iceland Met Office.

Currently there is strong wind around Katla volcano. This strong wind is interfering with IMO SIL network around Katla. But so far no harmonic tremor has been detected after this earthquake.

This earthquake appears to have be formed due to magma intrusion into the rock in Katla volcano caldera. It’s signature on my geophone shows that clearly.


The Z component unfiltered. This picture is released under Creative Commons licence.


The Z component filtered at 1Hz. This picture is released under Creative Commons licence.


All the component on my geophone. This is unfiltered data. This picture is released under Creative Commons licence.


All the component on my geophone. This is filtered data at 1Hz. This picture is released under Creative Commons licence.

This might just be part of normal Katla volcano activity. But it is a fact that it has more earthquakes during the summer and autumn then during the winter. But it is close to impossible to know if this just normal activity or something else. All that can be done is to wait and see what happens.

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Donations and Google Adsense

This is a off-topic post:

I once more have to ask for donations. As I have been doing for past few months. The reasons are simple and have remained unchanged as before (check older blog post for details). But the cost of school this winter is something I can handle on my own, but with debt payments it does not leave anything leftover for me to spend on other stuff and food during weekends. But in the dormitory where I live there is only food during the week, not on the weekend.

I also want to try and keep a balance in my finances until I move back to Denmark. My debt payments are going well to and almost on target so far.

Google Adsense

I am quitting with Google Adsense. The reason is quite simple. They have not paid me and they don’t answer my emails on what the problem might be. As my account is on invisible hold with them. My rule is simple. I don’t do business with companies that behaves like this. All Google Adsense ads are going to vanish in the next three days or so. But I remove them when I have the time to do so. That is going to take around three days in my estimate. Now if Google Adsense fixes this issue in timely manner I am not going to quit using them, for now anyway. But given the current track record on this type of issues, I do not think that is going to happen.

I am going to replace the Google Adsense ads with Amazon Ads. But I have had no problem what so ever with Amazon when it comes to ads and payments. So I am going to keep using them.

Google Adsense has removed the hold on my account, so I am going to get paid from the on 1. October and onwards. So this issue should now be fixed forever I hope. I have started to add Google Adsense ads back to my blog and web pages.

Thanks for the support and understanding.

Blog post updated at 20:06 UTC on 1. September 2011.

Blog post updated at 03:03 UTC on 3 October 2011.

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Minor harmonic tremor in Katla volcano

There seems to have been minor harmonic tremor in Katla volcano this evening. This harmonic tremor seems to have started after a ML0.7 earthquake with the depth of ~3.7 km did happen inside the Katla volcano caldera. Last harmonic tremor spike did take place on the 24th of August according to the tremor plot on Icelandic Met Office web page.


Harmonic tremor mixed in with the earthquakes from Katla volcano on this tremor plot. Copyright of this image belongs to Icelandic Met Office.


Here is the harmonic tremor that I see on the tremor plot. It is the second spike. But the first spike is actually a earthquakes that did happen earlier today. Copyright of this image belongs to Icelandic Met Office.


This harmonic tremor can also be seen on this SIL station clearly. Copyright of this image belongs to Icelandic Met Office.

On other SIL stations around Katla volcano the signal is not so clear. But this is really a small event and unlikely a pre-eruption event. But it is hard to know it for sure, as Katla volcano has done this before and there was no eruption following this type of events. All that can be done now is to wait and see what happens next. It is also important to notice that Icelandic Met Office has not confirmed this harmonic tremor spike yet.

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Iceland government to increase monitoring and research into Iceland volcanoes

Iceland government did approve today to increase funding for research into Iceland volcanoes. But this is also part of a plan for a risk assessment for volcanoes in Iceland. But it is expected that this research is going to take 15 to 20 years. Funding has already been increased to Icelandic Met Office by grands from ICAO (among other I think, but I do not have it confirmed). But this is a direct response to the fact that Eyjafjallajökull volcano and Grímsfjall volcano have erupted in short time span (11 months apart).

But the Icelandic government is expecting a eruption in Grímsfjall volcano every two to seven years. But it is also expecting eruptions in Bárðarbunga volcano following this increased activity in Grímsfjall volcano. But eruption period often follow in Bárðarbunga volcano when activity increases in Grímsfjall volcano.

First step of this research is going to take three years to finish. But the news does not say what they are going to cover in this research. This risk assessment is done by the standards of U.N and WMO.

Icelandic News about this.

Hefja vinnu við hættumat fyrir eldgos – tekur 15 til 20 ár í heildina (Vísir.is, Icelandic)

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Earthquake close to Hekla volcano. A earthquake swarm in Katla volcano

This has been a busy weekend in earthquakes, more then I was expecting. Here is a minor write up on the activity so far.

Hekla volcano:

A ML2.4 earthquake did happen close to Hekla volcano at 07:30 UTC. Depth of this earthquake was 3.7 km. The earthquake did happen on earthquake fault line that was created in a large earthquake in the year 1912. This fault line has been known since then and is well documented.


The SISZ earthquake this morning. This picture is released under Creative Common Licence. See Licence web page for more details.

Katla volcano:

Two new earthquake swarms took place in Katla volcano today. This earthquake started around 09:30 UTC this morning. Most of the earthquakes where smaller then ML1.0 in size. The depth was around 5.5 km on average. The largest earthquake was ML2.3 in size, with the depth of 5.5 km. That earthquake swarm was in Goðabunga area of Mýrdalsjökull glacier (Katla volcano). But here was also a minor earthquake swarm inside Katla volcano caldera. But in that earthquake swarm the earthquakes there where even smaller, most of those earthquake didn’t reach the size ML1.0. The earthquake swarm in Goðabunga area in Katla volcano might be due to dike intrusion in that area. I do not know if this might be something else. But given the data, this is the most likely the reason for this earthquake swarm in this area. The earthquake swarm did stop at 12:47 UTC. After that everything has been quiet so far.

Few earthquakes also did happen SE part of the Katla volcano caldera. But there have been earthquakes in this area since July. But this activity did start soon after the glacier flood from Mýrdalsjökull glacier.


Earthquake activity in Katla volcano. Copyright of this picture belongs to Icelandic Met Office.

All the earthquake swarms of today in Katla volcano, also the single earthquake close to Hekla volcano.

Icelandic news about this activity.

Mikið um smáskjálfta nærri Mýrdalsjökli (Vísir.is)
Jörð skelfur nálægt Hellu (Rúv.is)

Other: Short announcement. I have finally figured out how I am going to have my writing schedule. But my working period is going to be from 1. September to 1. June every year. This also means more activity on this blog and my other (Icelandic) blogs. During the summer time there is going to be reduced activity on all my blogs. But if something happens during the summer in earthquakes and volcanoes. I am going to write about it anyway or soon as I can do so.

Also note that I have started school to finish basic in electronic (house electronics and other basics in electronics). So I am busy during the day (most days). So my response might be slower then normal if anything happens in Iceland with earthquakes or volcano activity.

Other #2: I am having minor issues with uploading the gif images from my earthquake computer at the moment. So that is currently being done by the remote geophone computers at the moment. Because of this, there is no red colour if a large earthquakes happens in Iceland or close to a geophone station that I have up and running.

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Earthquakes in Öræfajökull volcano

I do not have a time for long blog post about this at the moment. But here is a short overview of earthquake activity in Öræfajökull volcano.

Since the year 1991 there have been total of three earthquake swarms (with the one in last week) in Öræfajökull volcano. The two earthquake swarms where in the year December 2005 and in September 2008. Total of 70 or so earthquakes have taken place in this earthquake swarms. But only 30 or so earthquakes in the main crater of Öræfajökull volcano.


Earthquake activity in Öræfajökull volcano between the year 1991 and to 2011. Copyright of this image belongs to Icelandic Met Office.


Earthquakes inside the main crater of Öræfajökull volcano from the year 1991 to 2011. Copyright of this image belongs to Icelandic Met Office.

All pictures are from here.

Currently the earthquake activity in Öræfajökull volcano is quite low. So I am not expecting anything for a long, long time now. The reason why earthquakes are taking place might be new magma. But this also might be due the glacier and pressure changes on the rock because of that. But I find the later idea less likely then the first one. But it hard to know for sure at the moment what actually is the real case now.