Category: Harmonic tremors

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Harmonic tremor level drops in Grímsfjall volcano

During the night. Harmonic tremor levels started to drop in Grímsfjall volcano. The reason for this harmonic tremor level increase remain unknown and unclear. But no volcano related activity has been seen or recorded so far in Grímsfjall volcano.


Harmonic tremor levels in Grímsfjall volcano. This is high resolution image. Copyright of this image belongs to Icelandic Meteorological Office.


Harmonic tremor levels in Grímsfjall volcano. This is low resolution image. Copyright of this image belongs to Icelandic Meteorological Office.

Some earthquake activity has been taking place following this events. But the earthquakes have been small and do not suggest anything is about to take place in Grímsfjall volcano.


Earthquake activity in Grímsfjall volcano for the past 48 hours. Copyright of this image belongs to Icelandic Meteorological Office.

So far Grímsfjall volcano has remained quiet during this glacier flood. With nothing suggesting that it is going to change soon. As for the glacier flood it self. According to latest news it seems to have peaked and is now dropping. But this was a small glacier flood. With just rise about 153 cm. But that is quite small compared to many older glacier floods from Grímsfjall volcano.

Icelandic News about this glacier flood

Hlaupið í Grímsvötnum virðist hafa náð hámarki (Vísir.is)
Hlaupið í Gígjukvísl í rénun (Rúv.is)

Blog post updated at 12:48 UTC on 27.11.2012

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Unclear what is going on in Grímsfjall volcano

It is unclear what is going on in Grímsfjall volcano at this moment. Harmonic tremor level continue to rise. They are currently way above what is normal for minor glacier floods from Grímsfjall volcano. This might be a minor eruption, or it might just be glacier on the move inside caldera. Whatever it is. This is not a strong event. As it only appears so far on only one SIL station. The one located on top of Grímsfjall volcano. Other SIL stations do not show any change so far. There is no earthquake activity in Grímsfjall volcano so far following this activity.


Grímsfjall volcano tremor levels this morning at 09:20 UTC. This is high resolution image. Copyright of this image belongs to Icelandic Meteorological Office.


Tremor levels at Grímsfjall SIL station (low resolution). The spike is maybe an earthquake. Copyright of this image belongs to Icelandic Meteorological Office.

So far nothing there is no word from Icelandic Meteorological Office on what is going on in Grímsfjall volcano. I am also uncertain what is going on in Grímsfjall volcano at present time. But I am sure that is going to get clearer in the next few hours. The harmonic tremor level appears to be continue to rise. So it might get confirmed in the next few hours if there is an eruption in Grímsfjall volcano or not.

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Weak harmonic tremor pulse from Hamarinn volcano

Since around 19:00 UTC (16.10.2012) a harmonic tremor pulse has been taking place in Hamarinn volcano (Bárðarbunga volcano). There is in my view no eruption taking place at the moment. This is most likely a dike intrusion of magma somewhere in the area of Hamarinn volcano. That might however trigger an eruption. But we just need to wait and see on that for the time being. This activity is interesting, as there was a small eruption in this area in July 2011.


The harmonic tremor pulse is strongest on this SIL station. But it is weak regardless. The signal suggest this event is taking place close to this SIL station location. Copyright of this image belongs to Icelandic Meteorological Office.


The harmonic tremor pulse also appears on Skrokkalda SIL station. But is weak and can hardly be detected on it. Copyright of this image belongs to Icelandic Meteorological Office.

The harmonic tremor pulse can be seen at the end of the above SIL station traces. The harmonic tremor pulse is higher then normal background noise (wind, ocean waves, human traffic, etc) on the SIL station. I do not expect this to be noise. The signal is too strong for that. It also hard to travel in this part of Iceland in October due to bad weather and difficult conditions in the high areas of Iceland.

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Harmonic tremor pulse activity maybe in Hamarinn volcano

Today (02.09.2012) a harmonic tremor pulse did start in Hamarinn volcano (best guess) (Bárðarbunga volcano). This harmonic tremor pulses are intermittent and normally last for up to 20 to 30 min., at the time. What is creating them is hard to say. But this might just be hydro-thermal activity taking place in Hamarinn volcano. This might also be magma on the move inside Hamarinn volcano. But nothing is confirmed so far. I do not expect anything to be confirmed any time soon.

The harmonic tremor pluses appear on the end of the traces on this image. They are bit hard to spot for the untrained eye. But they appear as higher then background noise change in the tremor plot image.


The harmonic tremor pulse as it appears on the SIL station at Grímsfjall volcano. This is high resolution image from this IMO web page. Copyright of image belongs to Icelandic Meteorological Office.


The harmonic tremor pulse at Skrokkalda SIL station. Copyright of image belongs to Icelandic Meteorological Office.


The harmonic tremor pulse at jok SIL station. Copyright of image belongs to Icelandic Meteorological Office.


Harmonic tremor pulse at dyn SIL station. Copyright of image belongs to Icelandic Meteorological Office.

It is impossible to know what this means exactly. But so far there are no signs of eruption in the area. This activity is less then activity in July 2011 that was created by an minor eruption in Hamarinn volcano. Stronger harmonic tremor pluses appear on SIL station at longer distance. But for now (when active) most of the activity only appears on SIL stations closest to the Vatnajökull glacier. I am going to continue to monitor the current situation. I will update or make a new blog post about what is going on if anything happens.

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Glacier flood confirmed from western Skaftárkatli cauldron

Today (30.08.2012) an glacier flood was confirmed from the western Skaftárkatli cauldron. This glacier flood is small as expected. But it did take several days longer to appear from Vatnajökull glacier then expected. Some hydro-thermal activity in Hamarinn volcano (Bárðarbunga volcano) seems to be currently taking place at the moment. But some harmonic tremor spikes have been taking place in the past two hours.


Harmonic tremor pulse can be seen at the end of this tremor plot from IMO. It only lasted for about 30 to 60 min. Copyright of this image belongs to Icelandic Meteorological Office.


Harmonic tremor pulse can be seen at the end of this tremor plot from IMO. It only lasted for about 30 to 60 min. Copyright of this image belongs to Icelandic Meteorological Office.


Harmonic tremor pulse can be seen at the end of this tremor plot from IMO. It only lasted for about 30 to 60 min. Copyright of this image belongs to Icelandic Meteorological Office.

It might be that this harmonic tremor signals are coming from other volcano system then Hamarinn volcano. This type of activity has been seen before in Hamarinn volcano and follows glacier floods from it. Given the activity last year. I cannot rule out volcano activity taking place now in Hamarinn volcano. New episode of harmonic tremor is now starting in Hamarinn volcano. Based on early observations . It seems that current activity is behaving in similar manner as did happen in July 2011 when an minor eruption took place in Hamarinn volcano. If that is the case now remains to be seen. But it should be clear in few hours what is exactly going on in Hamarinn volcano following this glacier flood.

Icelandic news about this glacier flood

Skaftárhlaup kom úr katlinum – myndband (Rúv.is, video)
Hlaupið kom úr vestari katlinum (mbl.is)

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Earthquake in Katla volcano today (17.08.2012)

Today at 15:48 UTC there was an magnitude 3.8, at the depth of 0.1 km in Katla volcano. This earthquake took place on the caldera rim in Katla volcano. No major harmonic tremor was detected following this earthquake. However some harmonic tremor was detected. But it was minor. This might have been hydro-thermal-activity or magma on the move. It is impossible to know for sure what is the case now. This earthquake did appear clearly on my geophone network. Mostly on the geophone station at Skeiðflöt and Heklubyggð.


The location of the earthquake in Katla volcano. It was located on the edge of Katla volcano caldera. Copyright of this image belongs to Iceland Meteorological Office.


Influence map of todays ML3.8 earthquake. This suggests that it was not felt in nearby populated areas. Copyright of this image belongs to Iceland Meteorological Office.


Tremor plot that clearly shows the earthquake of today. The spikes are the earthquakes that have been taking place in Katla volcano or close by areas. This is Alftagrof SIL station. Copyright of this image belongs to Iceland Meteorological Office.


This tremor plot shows some minor harmonic tremor following the earthquake in Katla volcano. The spikes show the earthquake from Katla volcano and areas close by. This is Austmannsbunga SIL station. Copyright of this image belongs to Iceland Meteorological Office.

It is impossible to know what this means exactly. But Katla volcano has been quiet since around middle of July. It remains to be seen if earthquake activity is picking up again or if this was just an single event.

Icelandic news about this earthquake

Jarðskjálfti í Mýrdalsjökli (Rúv.is, Icelandic)
Jarðskjálfti í Mýrdalsjökli (Vísir.is, Icelandic)
Jörð skalf við Austmannsbungu (mbl.is, Icelandic)

Blog post updated at 18.08.2012 at 11:51 UTC. Blog post title fixed for the future.

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Possible glacier flood from Grímsfjall/Grímsvötn glacier lake (Unconfirmed)

There seems to be a glacier flood did start this morning in Grímsfjall glacier lake. Based on the tremor, the glacier flood is already subsiding or something of that nature. So far this glacier flood has not yet been confirmed by monitoring scientists. So I am unsure what exactly what is going on. But current activity seems to have started around 13. June 2012, when the tremor changed from normal background noise to higher frequency noise. This can be seen on the SIL station from Grímsfjall volcano.


Grímsfjall SIL station tremor reading. The spike marks what seems to be a glacier quake taking place. Copyright of this image belongs to Iceland Meteorological Office.

This harmonic tremor started early this morning. But it can be up to 12 to 24 hours before the glacier flood is visible in the rivers that flow from Grímsfjall volcano.


The second SIL station that tremor appears on from Grímsfjall volcano. Copyright of this image belongs to Iceland Meteorological Office.

Until there is official conformation what is exactly going on in Grímsfjall volcano. It is bit hard to know exactly what is going on there at the moment. But I hope that it is going to be cleared up in the next few hours or tomorrow. There are no signs that an eruption has started in Grímsfjall volcano at current time. It is impossible to know if that is going to change following this events that are taking place in Grímsfjall volcano.

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Katla volcano warming up for an eruption. Small glacier flood continues

This is going to be a short blog post. As I am going to be short of table and a cheer for few more days.

It seems that Katla volcano is warming up for a eruption. As I did mention in last blog post. But there is more to this. As the glacier flood that started on the 28. April 2012 continues according to a email that I got from an geologist working at Iceland Meteorological Office. But that suggests two things. That there is currently an ongoing melting of glacier taking place in Katla volcano, or there is a slow drainage taking place from some area in Mýrdalsjökull glacier. But given increased conductivity following this it is clear that this water has been in contact with magma. But that can be seen with the increased conductivity in the water.

There have not been many earthquakes following this events. But from the earthquakes that have happened. It seems that most likely source for current events is close to or the same area that erupted in July 2011. But at the moment this is just speculation based on limited data. It has not been confirmed so far.


The harmonic tremor that started on 28. April 2012. This is Lágu Hvolar SIL station. Copyright of this picture belongs to Iceland Meteorological Office. Used with written permission.

This plot shows clearly how the harmonic tremor starts and continues at same level for several days. I do not know if the harmonic tremor is ongoing. But I find it likely, if the small glacier flood is currently going on (that was my last information, but things might have changed during the day). But it is hard for me to know that for sure. But based on latest data from the water monitoring system around Katla volcano, the spike in this glacier flood is most likely over for now. But it impossible to know what happens next in Katla volcano. All that can be done is to wait and see what happens next.

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Small glacier flood from Mýrdalsjökull glacier on 28. April 2012 [Updated]

This has to be short. I do not have any table to cheer right now. I have already bought one (used and cheap). But I get it next week. I also do not yet have a ADSL connection so far. But this is what happens when one moves between countries.

On the 28. April 2012 there was a small glacier flood from Mýrdalsjökull glacier that on top of Katla volcano. This activity did start few days earlier according to Iceland Meteorological Office. But it did peak on the 28. April 2012. This was then followed by a small glacier flood in Múlakvísl river. The same river that had the glacer flood last summer, that did destroy a bridge in that same area.


The red line marks the harmonic tremor of Katla volcano. The blue line marks the conductivity in Múlakvísl glacier river. This is from Week 18 of the year 2012. Copyright of this picture belongs to Iceland Meteorological Office.

There was also a second event that took place in Katla volcano on 6 and 7. May 2012. But I do not know if there was any glacier flood in Múlakvísk glacier river following that event. Buit it is clear that Katla volcano is warming up again. This events are clearly something that I consider a warning on what is going on in Katla volcano. But it is a question if it continues or just stops, as so often does happen with volcanoes.

Update 1: According to a email answer that I got with a question of mine. This glacier flood is currently ongoing. It has not stopped so far. But this is a small glacier flood. But this is a interesting what is going on in Katla volcano at the moment.

Icelandic news about this.

Smáhlaup í Múlakvísl (mbl.is, Icelandic)

Blog post updated at 14:38 CEST on 11.05.2012.

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Harmonic tremor event in Hamarinn volcano

Tonight there was an small harmonic tremor event in Hamarinn volcano (Loki-Fögrufjöll, Bárðarbunga). This event was not big. But did appear on the Skrokkalda SIL station and on Grímsfjall SIL station. The pattern that is now appearing is the same one that did appear in July 2011 in the minor eruption in Hamarinn volcano. But that event took place week after Katla volcano minor eruption.


The harmonic tremor pulse on Skrokkalda SIL station. This is most likey from Hamarinn volcano. Copyright of this picture belongs to Iceland Meteorological Office.


The harmonic tremor pulse on Grímsfjall SIL station. This is most likey from Hamarinn volcano. Copyright of this picture belongs to Iceland Meteorological Office.

What gives clues that this Hamarinn volcano is that few days ago it had minor earthquake activity. But this area does not seem to need a lot of earthquake activity before a minor eruption takes place. Why that is I have no idea at present time.

I am going to update this blog post as event progress.