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.

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.

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)

New harmonic tremor detected. But it is not from Katla volcano

Some other and unknown volcano dedicated to join the spotlight in Iceland by starting making it’s own harmonic tremor. I do not yet know what volcano this is. But most likely it is the Hamarinn volcano. But that is part of Bárðarbunga volcano.


Skrokkalda SIL stations 07:49 UTC this morning. The first harmonic tremor spike seen on that SIL station. Copyright of this image belongs to Icelandic Met Office.


Skrokkalda SIL station 19:09 UTC. The third harmonic tremor spike in progress when this graph was saved. Copyright of this image belongs to Icelandic Met Office.

I do not know what volcano is making this noise since there are no earthquakes. But I now find this most likely to be an dike intrusion somewhere close to Skrokkalda SIL stations. Other volcanoes that might be creating this harmonic tremor is the volcano Tungnafellsjökull volcano or the volcano that Skrokkalda SIL station actually is on top of.

But both of those volcanoes have been dormant for an long time now. So I find that to be unlikely, but not impossible. Until a earthquakes happens or something else that actually shows the area of activity in question. This is all just a guess work out in the blue.

Update 1: There is more going on there now then when this first did start. I did record an earthquake from this harmonic tremor around 00:30 UTC. This earthquake was extremely low period as can be seen on this picture.


This earthquake took place around 00:30 UTC on 13. July 2011. It is filtered at 1Hz and is extremely long period earthquake. This suggests that magma did create this earthquake. This picture is released under Creative Commons Attribution-ShareAlike 3.0 Unported License. See the Creative Commons Licence web page for more information.

Blog post updated at 01:02 UTC on 13. July 2011.

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.

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)

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.

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)

Harmonic tremor drop down. New earthquake happen in Katla volcano caldera

It seems that on many SIL station around Katla volcano that the harmonic tremor has gone mostly down to background levels, on other stations it continues to drop. This are mostly SIL stations that are at the most distance to the source of the area that this minor eruption took place during the night. But at the moment this seems to be over. The main source of the activity appears to be where the eruption took place in the year 1918, or so scientists think at the moment.

According to the news there was an flood wave around 04:00 UTC during the night. When the water meters did show an rise of 5 meters suddenly. Soon after that the bridge over Múlakvísl river was lost in the glacier flood. This did close the main road 1 in this area, that area of the main road is going to remain closed for the next few weeks while they fix the damage done in the flood (build an new bridge).

Even if the harmonic tremor seems to be dropping. This does not seem to be over, as an earthquake activity did resume from around 13:00 UTC in the Katla. Since then the earthquake activity seems to have been building at slow rate.


Tremor plot at 18:23 UTC. The tremor is dropping. It also shows that earthquakes are taking place (spikes the tremor chart). Copyright of this picture belongs to the Icelandic Met Office.


Tremor chart from Goðabunga at 18:24 UTC. Copyright of this picture belongs to the Icelandic Met Office.


Dropping harmonic tremor on Lágu Hvolar. Earthquakes appear as spikes here. Copyright of this picture belongs to Icelandic Met Office.


Dropping tremor and earthquakes as before. Copyright of this picture belongs to Icelandic Met Office.


Earthquakes as they are tonight. The southern part of the caldera is having earthquake swarm, even if it is just an small one. Copyright of this picture belongs to Icelandic Met Office.

I am waiting too see how this develops. Something larger might happen. But nothing else might happen for an while in Katla volcano. The only thing that can be done is too wait and see what happens in Katla volcano.

Icelandic News about the road damage.

Meiri skemmdir en talið var (Rúv.is, Picture, Icelandic)

Harmonic tremor still high in Katla volcano

Currently harmonic tremor remains high in Katla volcano. But at the moment the harmonic tremor is dropping. Earthquakes have also stopped for the moment. But currently the harmonic tremor is well above the background level for this area. It is still not clear if this was an eruption or just hydrothermal areas clearing it self of extra water. But in the news at Rúv noon they did report that the ice cauldrons that are normally there had deepened over the past few weeks in Mýrdalsjökull glacier.

Update 1: Earthquake activity has stopped for the moment. But I am expecting it to resume soon. As I do not think that this event is over, even if it has just paused for the moment.

Three cauldron have formed in Mýrdalsjökull glacier and large cracks have formed around them. All traffic has been banned on Mýrdalsjökull glacier and the glacier that comes from it.

Here are the current tremor charts from Icelandic Met Office web page.


Harmonic tremor is dropping as can clearly be seen on this picture. Copyright of this picture belongs to Icelandic Met Office.


Harmonic tremor is dropping as can clearly be seen on this picture. Copyright of this picture belongs to Icelandic Met Office.


Harmonic tremor is dropping as can clearly be seen on this picture. Copyright of this picture belongs to Icelandic Met Office.

I am going to post update on Katla volcano later today and earlier if anything major happens.

News with picture of the Mýrdalsjökull glacier. It is covered with dark ash from Eyjafjallajökull volcano eruption last year and volcano ash from the eruption in Grímsfjall volcano 2011.

Miklar sprungur í sigkötlunum (mbl.is, Picture, Icelandic)
Svona lítur jökullinn út (Rúv.is, Icelandic, Picture)
Þrír greinilegir sigkatlar (Vísir.is, Icelandic, Picture)
Brúin rofnaði af í heilu lagi (Vísir.is, Icelandic, Picture)
Óvissa um hlaup eða lítið eldgos (Rúv.is, Icelandic, Pictures)

Blog post updated at 13:13 UTC 9. July 2011.