Category: Earthquakes

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Overview of Hamarinn volcano current activity

Here is a short overview of the Hamarinn volcano activity this summer. From what I can gather in the current data this is most likely not over. During the past few days there have been at least suspected two minor eruption in Hamarinn volcano. But it hard to confirm it due to glacier that is covering this area.

This all starts on 12. July 2011 at 07:30 UTC with this event here.


The tremor spike on 12. July 2011 at 07:49 UTC. Copyright of this picture belongs to Icelandic Met Office.

When the clock is around 19:10 UTC the same day the tremor chart looks like this.


The tremor spikes are now three on 12. July 2011 at 19:09 UTC. Copyright of this picture belongs to Icelandic Met Office.

On the 13. July 2011 the tremor plot looks like this. But at that time the glacier flood had started and broken from the Vatnajökull glacier.


The tremor chart at 13. July 2011 at 01:10 UTC. Copyright of this picture belongs to Icelandic Met Office.


The tremor chart at 13. July 2011 at 12:59 UTC. Copyright of this picture belongs to Icelandic Met Office.

Then there was a short period of break when nothing interesting happened in Hamarinn volcano. That break did last until 16. July 2011 when a new, but smaller spike did appear on Skrokkalda SIL station.


The tremor at 16. July 2011 at 15:22 UTC. It is not fully clear what did happen at this time. But this was most likely a earthquake in Hamarinn volcano. But that is yet unconfirmed at this time. Copyright of this picture belongs to Icelandic Met Office.

Then there is a new break that lasts until 1. August when a earthquakes happens deep under Bárðarbunga volcano. But the deepest earthquake had the depth of 25.2 km. But it is also important to notice this earthquake that took place on 13. July 2011 and it is from Hamarinn volcano.


The earthquake from Hamarinn volcano. This picture is released under Creative Commons licence. Please see licence web page for more details.

On the 3. August 2011 around 02:00 UTC a new harmonic tremor spike starts to be visible on Skrokkalda SIL station.


The tremor plot at 01:55 UTC on 3. August 2011. Copyright of this picture belongs to Icelandic Met Office.

This day two minor harmonic tremor happens. A change in Skaftá glacier river is noticed. That is higher conductivity and slightly more water. It was announced in the news that a Skaftá glacier river flood was about to start from the eastern glacier cauldron that is formed above the Hamarinn volcano. Today however that does not seem to be the case. As no glacier flood has taken place so far.

Today (5. August 2011) there was a new harmonic tremor spike on Skrokkalda SIL station. It did follow the same pattern as before. It started and lasted for about 20 to 60 minutes or about that long.


The tremor chart 5. August 2011 at 17:38 UTC. Copyright of this image belongs to Icelandic Met Office.

So far today only one harmonic tremor has been detected. But given the past experience that is unlikely to hold for a long time now. But it is impossible to know when a new event starts or how big it is going to be.

The original event on 12. July 2011 did create new cauldron in the glacier. This map from Icelandic Met Office shows the location of those new cauldrons. But it has been marked with a star on the map. The coloured dots are earthquakes in this area over the past few years.


Map of the area that is currently active in Hamarinn volcano. Copyright of this image belongs to Icelandic Met Office.

Given the current data I am expect a full scale eruption in this area soon. When is hard to know for sure. But until that happens there are going to be more smaller eruptions in this area. I do not know why there is a lack of earthquakes following this events. I cannot explain it. But because of that this can only be seen after it has started on the tremor charts.

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Hekla volcano earthquake from early this morning

Here is the earthquake that took place in Hekla volcano this morning. This earthquake was small, just ML2.02 with the depth of 4.8 km. Because of how close this earthquake was to my geophone at Heklubyggð it did appear clearly on it.


The earthquake at Hekla volcano this morning. This picture is released under Creative Commons License, see License web page for more details.

No aftershocks where recorded after this earthquake and nothing suggests that a Hekla volcano is about to erupt at present time. But that can change without warning at any time.

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Earthquake swarm starts on the Reykjanes Ridge

It appears that a earthquake swarm has started on the Reykjanes Ridge. This earthquake swarm appears to have started with a earthquake that is ML3.6 to ML4.0 in size or larger. But I don’t think it is a Mb5.0 in size. On the earthquake list on the Icelandic Met Office web site there are several ghost earthquakes. But I did just record one earthquake on my geophones.


The current area of activity on the Reykjanes Ridge. Copyright of this picture belongs to Icelandic Met Office.

This looks like a normal earthquake swarm on the Reykjanes Ridge. So far nothing suggests that this means a eruption is about to start in this area. But that might change without warning since this is a volcano area.

I am going to update this blog post if there are any more strong earthquakes on the Reykjanes Ridge.

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Interesting earthquakes in Bárðarbunga volcano system (Hamarinn volcano)

At 02:06 and 02:07 UTC there where interesting earthquakes in Bárðarbunga volcano system. What makes them interesting is that fact they did happen at 0.6 km depth one of them. But this area did see some volcano related activity (speculated) earlier this summer, that did result in large glacier flood. But it has been suggested that a minor eruption took place there around 10. July 2011.


The two earthquakes can be seen as spikes at the end of this tremor plot from Icelandic Met Office. Copyright of this picture belongs to Icelandic Met Office.

What makes this earthquakes so interesting is that they seem to have a low period component in them. But it was seen on the Kálfafell SIL station, and other SIL station that was decent distance from the source of the earthquake.


The two earthquakes can be seen as spikes at the end of this tremor plot from Icelandic Met Office. Copyright of this picture belongs to Icelandic Met Office.

Currently there is nothing that suggests that a eruption is about to start in this area. But that can change without warning given the current status of Hamarinn volcano system.

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Earthquake swarm and minor harmonic tremor in Katla volcano

There has been a minor earthquake swarm in Katla volcano today. This earthquake swarm started around 09:00 UTC and lasted with breaks until 14:39 UTC. The largest earthquake in this swarm was ML1.7 with the depth of 3.5 km. Following this earthquake swarm there was a small harmonic tremor spike seen on few SIL stations around Katla volcano. It is unknown at this time if there has been a small glacier flood taking place. But if that is the case, it should be known in the next few hours if that is the case or not.


The earthquake swarm in Katla volcano caldera. Copyright of this picture belongs to Icelandic Met Office.


The harmonic tremor spike can be seen on this SIL station. It is located close to the end of tremor plot. Copyright of this picture belongs to Icelandic Met Office.


The harmonic tremor spike can be seen on this SIL station. It is located close to the end of tremor plot. Copyright of this picture belongs to Icelandic Met Office.

This harmonic tremor is small, but larger then last harmonic tremor that took place in this are about one week ago (far as I can remember). Currently there is nothing that suggests that eruption is imminent. This is just earthquake activity in the same place as it has been for the past five or so weeks.

Sorry for the short blog post. I have gone sick with some cold. No advice needed on how to get rid of it. That is going to take few days on it’s own.

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Currently all is quiet in Iceland

At the moment it is rather quiet in Iceland in earthquakes and volcanoes. When that might change is impossible to say. But in the last few days there have been minor earthquake swarms on the Reykjanes Ridge. It is not related to volcanism, but rather tectonic movement along the rift zone.

There is continued minor earthquake swarm activity in Katla volcano. But it has quieted down from about two weeks ago. For the moment, the glacier floods seems to have stopped.

Other then this minor earthquake activity, everything is quiet in Iceland.

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Interesting earthquake activity in Katla volcano

Sometimes there is a strange earthquake activity in volcanoes. I do think that this qualifies as one of that cases. But there has been odd and what appears to be grown earthquake activity in SE part of the caldera rim in Katla volcano.


The earthquake activity is the earthquake spot the SE in Katla volcano, out side the caldera. Copyright of this picture belongs to Icelandic Met Office.

From what I can gather this activity started in Week 27 or about that time. Since then it appears to have been growing in number of earthquakes. I do not know yet if there have been any changes in the area, like hydrothermal activity.


Week 27. One earthquake can be seen in this area. Copyright of this picture belongs to Icelandic Met Office.


Week 28. More earthquakes in the same area. Clear sign that the activity is growing. Copyright of this picture belongs to Icelandic Met Office.


Weeek 29 (crurrent week) . Even more earthquakes at the same location. Copyright of this picture belongs to Icelandic Met Office.

While I do not yet what is going on there. This is something that might be interesting to watch and see what happens. Because small amount of magma might just have found a new pathway up the surface in this area. Even if it does not erupt, this might create new hydrothermal area if this is in fact magma. But given that this is in a volcano and really dense earthquake swarm. It is my guess that it is the case.

Power outage: Due to some maintenance work on the local power grid where I live I lost all power from 01:00 until about 06:20 UTC this morning. But that means that this blog post is late by several hours and my geophone webicorders have been off-line at the same time. Sadly I cannot afford few UPS like this one to keep my system up and running when the power goes out. As I need at least four of them at home and one with each webicorder computer (at location).

I am going to post update on what did happen during the night around 09:00 08:00 UTC. When I know more and after some more sleep.

Blog post updated at 07:29 UTC on 21. July 2011.

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Small earthquake swarm in Katla volcano caldera

At the moment there appears to be a small earthquake swarm in Katla volcano. Currently this is just a earthquake swarm. All the tremor plots are normal and show no signs of harmonic tremors and magma on the move. The largest earthquake in this earthquake swarm in inside Katla volcano caldera was a ML1.3 with the depth of 1.7 km according to reviewed data from Icelandic Met Office.


The earthquake swarm in Katla voclano. It is deep inside Katla volcano caldera as can clearly be seen. Copyright of this picture belongs in Icelandic Met Office.


The ML1.3 earthquake as I did record it on my Heklubyggð geophone. Given the shape and how low period this earthquake is. I would say that it was created by magma pushing upwards in the crust inside Katla volcano caldera. This picture is released under Creative Commons licence, see the licence web page for more details.

At the moment (when this is written) it seems that this earthquake swarm is over. For the moment anyway. But it hard to know for sure if it resumes or something else starts in Katla volcano.

Update 1: A earthquake with the magnitude ML3.8 did happen in Katla volcano caldera at 02:02 UTC. Following this earthquake there have been many aftershocks. It is not yet clear if this means that Katla volcano is starting a eruption or not. But that should be clear in few hours if that is the case or not.


The ML3.8 earthquake that happened at 02:02 UTC. This is by the automatic SIL system, so it’s size can change. This picture is released under Creative Commons licence, see the licence web page for more details.


The location of the ML3.8 earthquake in Katla volcano caldera and the following aftershocks. Copyright of this picture belongs to Icelandic Met Office.

Blog post updated at 02:26 UTC on 18. July 2011.
Blog post updated at 02:40 UTC on 18. July 2011.

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Small harmonic tremor spike from Hamarinn volcano

There seems to be a small harmonic tremor spike taking place in Hamarinn volcano (Bárðarbunga volcano) at the moment. This tremor spike is not strong at the moment. This tremor spike appears to have been pre-seeded by few long period earthquakes (not all of the earthquakes seen on Skrokkalda are from Hamarinn volcano, few are from Katla volcano), but that suggests that magma is on the move in Hamarinn volcano. But this would the second harmonic tremor in a time period of 48 hours it seems.


The harmonic tremor spikes can be seen at the end of this tremor plot. Copyright of this picture belongs to Icelandic Met Office.

Currently it is impossible to know what happens in Hamarinn volcano. As it’s pre-eruption behaviour is rather unknown. But if there is a eruption in this area I am expecting a lot of earthquakes, with size well over ML3.0.

Blog post updated at 16:20 UTC.

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Possible minor eruption in Hamarinn volcano yesterday. Update on Katla volcano

There appears to be more in this new hydrothermal activity in Hamarinn volcano then at first sight. It seems that this actually might have a eruption in Hamarinn volcano (Bárðarbunga volcano). If this event is confirmed, this is the first eruption in Hamarinn volcano since the year 1910.

This also mean that there is a chance of more activity in this area in coming weeks or months. But when it might happen is impossible to know.


The new cauldrons are marked with a “X” on this map. Copyright of this picture belongs to Icelandic Met Office.

This eruption was really small and did just last for few hours. But it was able to melt a lot of ice and create rather large glacier flood from Vatnajökull glacier. If the activity resumes in this area this is going to repeat it self in terms of glacier flood.

Icelandic News about this event.

Innskot af kviku (Rúv.is, Icelandic)
Eldgos gæti hafa brotist upp við Hamarinn (Vísir.is, Icelandic, Pictures)
Fundu nýjan sigketil (mbl.is, Icelandic, Pictures)

Sigketill við Lokahrygg (Icelandic Met Office, Icelandic, Pictures)

Update on Katla volcano

Here is a short update on Katla volcano. There have been repeated short burst of harmonic tremors taking place inside the Katla volcano caldera. This harmonic tremor spikes have been small and they are hard to see on the harmonic tremor graph that Icelandic Met Office has on-line. Other then this it has been quiet so far in Katla volcano.