Category: Earthquakes

Posted on

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.

Posted on

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.

Posted on

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.

Posted on

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.

Posted on

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.

Posted on

Glacier flood confirmed from Vatnajökull glacier, flood is from Hamarinn volcano (Loki-Fögrufjöll area)

The harmonic tremor that started yesterday has been confirmed to be coming from Hamarinn volcano (Bárðarbunga volcano), but they are also known as Loki-Fögrufjöll in GVP database.

So far there is nothing that indicates an eruption is taking place at the moment in Hamarinn volcano. But that might change without warning. At the moment nobody is sure where the glacier flood is coming from. But this appears to be a new area of hydrothermal activity in Hamarinn volcano that is releasing water at the moment. This new hydrothermal area is most likely created by new dike intrusions into the bed rock in the affected area. There are no pictures of the affected area, as the area is impassible to air plains at the moment due to cloud cover or fog. Lack of earthquakes also makes it hard to locate the source of this glacier flood.

Currently the glacier flood has peaked and is getting lower. There not expected to be any damage from this glacier flood on human structures or roads. This area of Iceland is unpopulated. The water is going into large lakes in the area where the effects of this glacier flood are almost none. The glacier flood did flow into a dam lake that is collecting water from rivers that this glacier flood did go into. This did make the lake rise about 70 cm in several hours and fill it. No damage is expected from this glacier flood to the dam or other structures in this area connected to the dam. But it is estimated that 26 gigaliters did flow into the dam lake during the night from this glacier flood.


Harmonic tremor at 12:59 UTC, this is Skrokkalda SIL station. At this time it had been dropping down. But starting to rise again after that when this is written. Copyright of this picture belongs to Icelandic Met Office.


This is the harmonic tremor at 12:59 UTC on Grímsfjall SIL station. It is bit hard to see it due high background noise on this SIL station. Copyright of this picture belongs to Icelandic Met Office.

So far this is just a glacier flood and nothing else. But that might change if an eruption starts in this area. But that is no way certain that it is going to happen now. We just have to wait and see what happens in Hamarinn volcano.

Icelandic News about this.

Hágöngulón fylltist í hlaupinu (mbl.is, Icelandic)
Hlaup undan Köldukvíslarjökli (mbl.is, Icelandic)
Jökulhlaup undan Vatnajökli (Vísir.is, Icelandic)
Hlaupið í rénun (Vísir.is, Icelandic)
Órói við Vatnajökul (Rúv.is, Icelandic)
Flóð undan Vatnajökli (Rúv.is, Icelandic)

Posted on

New harmonic tremor detected in Katla volcano

Earlier today there was an minor harmonic tremor in Katla volcano. It’s source was inside the Katla volcano caldera as before, it is impossible to know the exact location of the source this harmonic tremor spike. But earthquakes around that same time might give a clue about it’s origin.


Harmonic tremor can be found close the end of this tremor chart. It is peaks from the background noise that is currently taking place in Katla volcano on this SIL station. Copyright of this picture belongs to Icelandic Met Office.


Harmonic tremor can be found close the end of this tremor chart. It is peaks from the background noise, it small but it can be found. Copyright of this picture belongs to Icelandic Met Office.


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

This harmonic tremor spike was small compared to the one on 8 – 9. July 2011. But this means that this area continues to be highly active and dangerous in my opinion. While there currently is an little pause ongoing in this area. I do not think that current events are over. When they end and how I don’t have any idea. But I am guessing that this is going to end in an full eruption of Katla volcano. When that might happen is something I don’t have any idea about.

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

Posted on

Update on Katla volcano at 22:25 UTC

Here is an short update on Katla volcano.

There has not been a lot of earthquake activity in Katla volcano during the past few hours. The harmonic tremors are back to normal. But show increased noise from the glacier due the formation of the cauldron in it.

Here is an picture of the current travel ban area. The red lines mark the travel ban area on Mýrdalsjökull glacier. Picture is from Civil Emergency Authority in Iceland.

Other then this it is quiet in Katla volcano. But it important to notice that it is impossible to know for how long this quiet time is going to last given the pattern of activity over the past few weeks in Katla volcano.

Next update on Katla volcano is going to be when it needs to be posted.

Icelandic News about this.

Minnka hættusvæðið á jöklinum (Rúv.is, Icelandic)

Posted on

Overview of current events in Katla volcano and current status

Here is an overview of the current events in Katla volcano. This is the short version, as I have not had the time to go over all the data collected so far.

12 June: On this day I did notice the first harmonic tremor spikes. This tremor spike was small and only noticed on few SIL stations around Mýrdalsjökull volcano. No earthquake activity was detected following this event. At least no earthquake activity that was unusual in my opinion.

17 to 18 June: The first earthquake swarm took place on this day that I connect to the current events. This earthquake swarm was special and different from the normal earthquakes that I see in Mýrdalsjökull volcano caldera. It was how dense this earthquake swarm was. There was no or little harmonic tremor following this earthquake swarm.

21 June: New harmonic tremor spike took place in Katla volcano on this day. It was a bit stronger then the first one. But lot smaller then what did happen this weekend.

28 June: What appears as an glacier earthquakes did appear on this day. Along with normal earthquake activity inside the Katla volcano caldera.

After this the events of July 8 start, it did end on the 9 July after what is most likely an minor eruption inside the Katla volcano caldera. This event is over it seems and Katla volcano has once again paused. But that has happened repeatedly over the past few weeks. The time between stops is different and it is impossible to know when the current pause ends. It is also impossible to know what happens next time activity picks up in Katla volcano caldera. Currently the earthquake activity continues in the Katla volcano caldera, but there are few earthquakes happening now then earlier this weekend.

For now all that can be done is to wait and see what happens.

Posted on

All quiet at Katla volcano

Currently everything is quiet in Katla volcano. At the moment the harmonic tremor level have gone back to normal levels. But there appears to be some earthquake activity taking place inside Katla volcano caldera. But most of this earthquakes do not appear on the automatic earthquake list that IMO has. But it might be impossible to actually locate this earthquakes as they might just appear on single or two SIL stations.

The glacier flood is over and the flood water have continued to lower during the day.

It is hard to know for sure what happens next. But the current events started around 17. June when earthquake swarms started to appear on the Katla volcano caldera. This has been developing rather fast since then. I do not expect that to change any time soon. But what I think was harmonic tremor pulses started around 12. June.

For now however all that can be done is to wait and see what happens in Katla volcano. As I do not think that this is over. But we might be in for an few hours or days of an break until something new happens in Katla volcano.

Icelandic News about this.

Einungis brúin eftir (Rúv.is, Icelandic, Picture)
Highway no. 1 disrupted for weeks. (Rúv.is, English, German)