Category: Magma

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Grímsfjall volcano continues to prepare for a new eruption

As I did mention in a blog post from 16. January 2012. Grímsfjall volcano is preparing for a new eruption. That progress has not slowed down at all. I am rather sure that the eruption prepare progress in Grímsfjall volcano has sped up. But this is nothing confirmed at the moment. I am just noticing slow increase in earthquakes from Grímsfjall volcano.


Today’s activity in Grímsfjall volcano. Copyright of this picture belongs to Iceland Met Office.


Grímsfjall volcano activity in Week 11 2012. Copyright of this picture belongs to Iceland Met Office.


Grímsfjall volcano activity in Week 12 2012. Copyright of this picture belongs to Iceland Met Office.

It is impossible to know for sure when next eruption starts in Grímsfjall volcano. But at the current time, the clock is ticking down faster then it did before in my opinion. As is known from history. Grímsfjall volcano has erupted sometimes the year after. Even after a big eruption. As was the case last year (2011), when it had the largest eruption in 140 years.

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Pictures of a old volcano rift zone

Here is a picture of what remains of Snæfellsnes – Húnaþing Rift zone. But this rift zone was activity about 4 million years ago. I do not know why this part of the rift zone is visible. But it seems to have escaped glacier erosion during past 4 million years since it became extinct.


The visible part of the Snæfellsnes – Húnaþing rift zone that was active about 4 million years ago. The farm in this picture is called Bjarghús. This picture is released under Creative Common Licence. Jón Frímann Jónsson took this picture on 24.03.2012.


This is where the visible rift zone disappear back into the ground. Its visibility resumes at distance. This picture is released under Creative Common Licence. Jón Frímann Jónsson took this picture on 24.03.2012.


The Snæfellsnes – Húnaþing rift zone is number two on this picture. What can be seen above ground is just a small part of it. This picture has been released under public domain licence. See this web page here for more details. This picture is not 100% correct on the details on the rift zones in Iceland. But is a good start for it.

Older blog post about this area can be found here. I am not expecting any eruption in this area. But it is always a possibly of a volcanic cone popping up in area like this. As the closest volcanoes to this area are only at the distance of 80 to 90 km south of it. But that is the Langjökull volcano, in the north part of it.

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Minor earthquake cluster in Katla volcano caldera

There seems to be forming of minor earthquake clusters in Katla volcano caldera. But this has been following growing number earthquakes in Katla volcano caldera during past few weeks. This is most likely an signal of increased activity in next few weeks to months. But the increase does not have to been slowly up. It can be sudden as did happen in July 2011 in Katla volcano caldera when earthquake activity did increase suddenly and there was an small eruption without an warning.


Current earthquake activity in Katla volcano. Note the small cluster of earthquakes close the area where an small eruption took place in the year 1999. Copyright of this image belongs to IMO.

There has been some small cluster of earthquakes taking place in Katla volcano caldera. I am not yet sure what that means at the moment. However this might be clues to minor dike intrusions into Katla volcano caldera. But without more data, it is impossible to be sure on this detail at current time.

Last night there was an change in harmonic tremor on two SIL stations around Katla volcano. But due to high wind noise I am unsure what was going on. But it is possible that this was an small dike intrusion taking place close to Goðabunga part of Katla volcano, or this was an minor glacier flood that was taking place under the glacier. At current time I have no good idea what was going on.


The harmonic tremor on Smjörgil SIL station. The signal is unclear due to high wind noise. Copyright of this picture belongs to IMO.


The harmonic tremor signal on the Goðabunga SIL station. Due to high wind the signal is unclear and hard to see. Copyright of this picture belongs to IMO.

It is hard to know for sure what happens next in Katla volcano. But important signs can be found in earthquake patterns. But it is also important not to overlay broad interpret the data in the favor of an eruption taking place. As it is impossible to know for sure when Katla volcano erupts, and then how big. All we might get is an new small eruption like in July 2011. As Katla volcano can also have small eruptions like big ones.

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Continued harmonic tremor in Katla volcano

The harmonic tremor that started yesterday in Katla volcano continues. It is however at less strength then yesterday. Often there are small earthquakes following it. They can be poorly observed on my Heklubyggð geophone. Few earthquakes have happened during this unrest. GPS data is unreliable, as it has not been updates since mid December 2011 (why that is I do not know). At current time it seems that this harmonic tremor is dropping down at the moment. It is impossible to know for sure if this is the end of this tremor in Katla volcano for the moment or not.


The tremor noise as seen on Slysaalda SIL station. Copyright of this picture belongs to IMO.


The harmonic tremor noise as seen on Skrokkalda SIL station. Copyright of this picture belongs to IMO.

There are now two possible reasons why this is happening. This might be an increase in hydro-thermal activity in north part of Katla volcano. Second reason might be that this is magma moving around inside Katla volcano at depth, then out visible effects on the surface. That is earthquakes have not happened following this event to any extent. There have only been two registered earthquakes so far. There location is both poor and depth poorly located. It has been my experience that following smaller event of this type there is generally an earthquake swarm in Katla volcano caldera. The time is is from from this type of event to take place until the earthquake swarm takes place differs a lot.

Last minor eruption that took place in Katla volcano was on 6. September 2011. My blog posts about it can be found here. It was believed at the time this was water. But today I now think this was an small eruption rather then water flooding under Mýrdalsjökull glacier.

Strong harmonic tremor pulse starting in Katla volcano
Most likely water creating harmonic tremors in Katla volcano (for the moment)

Both blog posts are from 6. September 2011.

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Harmonic tremor pulse in Katla volcano

Today there was an harmonic tremor pulse in Katla volcano. I am not sure when this harmonic tremor pulse did start. But I am guessing around 15:22 UTC or maybe around 16:00 UTC. It seems that this harmonic tremor pulse was small, considering the activity in July 2011 in Katla volcano (an minor eruption). This harmonic tremor pulse seems to have happened in the north part of Katla volcano, outside the caldera from my best estimates but might well be inside it in the north part of it. But it hard to be sure on that detail. From what I can tell, this harmonic tremor pulse does not appear on my geophones clearly. But it might have appeared on Hekla geophone poorly. But it is hard to be sure on that due to wind noise. When this is written the harmonic tremor pulse appears to be dying down. But there is still an possibly that it might pick up again or an new one might start without warning. It is impossible to know for sure how long this is going to stop after this harmonic tremor pulse. This harmonic tremor pulse is due to dike intrusion in Katla volcano at depth, so earthquakes might not happen until it reaches shallower surface in the crust. If the dike intrusion gets that far to start with.


The possible location of the harmonic tremor marked by the poorly located earthquake in Katla volcano. Copyright of this image belongs to IMO (Iceland Met Office).


The harmonic tremor on the Slysaalda SIL station where it is the strongest. But that means it is closest to this SIL station. Copyright of this image belongs to IMO (Iceland Met Office).


The harmonic tremor pulse on Goðabunga SIL station. The harmonic tremor pulse is weaker here then on Slysaalda SIL station. Copyright of this image belongs to IMO (Iceland Met Office).


The harmonic tremor pulse on Skrokkalda SIL station. One of the SIL station that have the most distance from Katla volcano area where the tremor pulse is taking place. Copyright of this image belongs to IMO (Iceland Met Office).


The harmonic tremor pulse can clearly be seen on Lágu Hvolar SIL station. Copyright of this image belongs to IMO (Iceland Met Office).


The harmonic tremor on Smjörgil SIL station, it is located in the flanks of Eyjafjallajökull volcano. This SIL station is close to Goðabunga SIL station. Copyright of this image belongs to IMO (Iceland Met Office).

What happens next in Katla volcano is hard to know. It all comes down to wait and see what happens next in Katla volcano. Eruptions in Katla volcano in January – February time period are not common, but due happen at times. So this harmonic tremor pulse might be an advance warning of what is to come. But that is just speculation on my part. It is impossible to know for sure what happens in Katla volcano until it happens.

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Earthquake swarm in Katla volcano, earthquake in Hekla volcano

Tonight at 21:13 UTC there was an earthquake with the size of ML1.2, it had the depth of 0.1 km. But that is about 100 meters. This is the second earthquake in Hekla volcano during that past three weeks (almost an month since last earthquake did happen in Hekla volcano). So far nothing more has happened. But that might change without warning.


The earthquake in Hekla volcano. It is the red dot in Hekla volcano. Copyright of this picture belongs to IMO.

Katla volcano

Today at 16:04 to 16:27 UTC there was an minor earthquake swarm in Katla volcano. The largest earthquake had the size of ML2.6, with the depth of 1.4 km. Like before this earthquake swarm was because of an dike intrusion into Katla volcano caldera. But this suggests that the unrest that started in Katla volcano in July 2011 is not over. But for the moment it continues at lower rate then before. But that might also change without warning at any time.


The earthquake swarm in Katla volcano. The earthquake in Hekla volcano can also be clearly seen on it. Copyright of this picture belongs to IMO.

It is impossible to know for sure what is going to happen next in both of this volcano. But it is clearly worth watching what is going on. The earthquake in Hekla volcano can clearly be seen on my Heklubyggð geophone, as it forms an clear spike on it, the web site can be found here. Same does the largest earthquake from Katla volcano earlier today.

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Interesting earthquake activity in El Hierro volcano

Over the past two weeks there has been interesting earthquake activity in El Hierro volcano in Canary Islands. What is so interesting about this earthquakes is the fact they are getting more shallow every day or so. Currently the most shallow activity that has been taking place is around 6km depth. But this is an rise from about 12 km depth.

What this means in my opinion is that magma is most likely rising to the surface at the location where the earthquakes are currently taking place (dike intrusions). This did happen before the first eruption in Eyjafjallajökull volcano. So it is an important to keep an eye on this earthquakes and where they happen, as eruption might take place in nearby area of this earthquakes. As magma might, and most likely is going find an clear path to the surface soon. The last part of that before an eruption might happen with no noticeable earthquakes at all. They might well be just over ML2.0 in magnitude or smaller.


Earthquake activity in El Hierro volcano over the past 10 days. Copyright of this image belongs to ING.

It is impossible to know for sure when or if an eruption happens in this area. But I find that is most likely going to be the case given the current activity. When and where is impossible to know for sure at current time.

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Earthquake swarm on Reykjanes Ridge this morning

This morning at 05:48 UTC an earthquake swarm started on the Reykjanes Ridge. The earthquake swarm is believed to have been created by an dike intrusion in the area. Around 40 earthquakes have been recorded so far, the largest ones have had the size over ML3.0 in magnitude. But at the moment the earthquake swarm has stopped or is doing some idle time. As this earthquake swarm was created by an dike intrusion. It is not impossible that is going to resume in few hours to days time. But it is hard to know for sure what happens next in this area.


The area of activity. Please note that some earthquakes have wrong location due the distance from the SIL network. Copyright of this picture belongs to IMO.

This activity of dike intrusions suggests that this area of Reykjanes Ridge is getting more active then it has been since the year 1926, when the last confirmed eruption took place. But there might have been unconfirmed eruptions on the Reykjanes Ridge in the years 1966 and in 1970. It is also most likely that dike intrusion activity is going to continue for some time now. But as I sad above, it is impossible to know how long the breaks are going to be between activity episodes. Last large earthquake swarm in this area took place in early 2010 (Erik blog post about it can be found here). That activity was about one month before the eruption in Eyjafjallajökull volcano.

Largest earthquakes of this earthquake swarm appeared clearly on my geophones where the noise level was not too high. They can be viewed here on the 24 hour plot.

Icelandic news about this activity. Use Google translate and hope make sense of it.

Skjálftahrinan í rénun (Rúv.is)
Skjálftar við Eldey (Rúv.is)
Jarðskjálfti upp á 3,8 stig (mbl.is)
Á fjórða tug skjálfta við Eldeyjarboða (DV.is)

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Eruption in Etna volcano

Tonight around 21:00 UTC an eruption started in Etna volcano. From the views of the web cameras that watch Etna volcano. This eruption seems to be rather small. I do not expect it to get any bigger.


Web camera picture of the eruption in Etna volcano. Copyright of this picture belongs to Radio Studio 7, Italy.


Web camera picture of the eruption in Etna volcano. Copyright of this picture belongs to Radio Studio 7, Italy.

Eruptions in Etna volcano are frequent, so this event is no surprise that it is currently taking place. Live web camera feed can be found here.

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More earthquake activity in Katla volcano

Yesterday (05.02.2012) there was an new earthquake swarm in Katla volcano. This activity suggests that it was due to dike intrusion as before in the Katla volcano caldera. The largest earthquake was ML2.1 with the depth of 0.1 (~100 meters) km. So this where really shallow earthquakes this time around.


The location of the earthquake swarm in Katla volcano yesterday. Copyright of this picture belongs to IMO.

This pattern of activity has been ongoing since July 2011, when a minor eruption took place in Katla volcano caldera. I am expecting this pattern of activity to continue for some time now. For how long I do not have any idea. It depends if this going to end in a larger eruption then took place in Katla volcano in July 2011 or if this is going to quiet down one day for several more years.

Activity in Katla volcano can be observed on Iceland Met Office pages. It also can be observed on a geophone that I run in Skeiðflöt (website here), a farm located few km south of Katla volcano.