Category: Earthquakes

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More information on the Askja volcano earthquakes

The earthquake activity in Askja volcano continues to evolve at rather fast phase. A lot faster phase then I did originally expect. Far as I can tell from the Icelandic Met Office SIL data (tremor plots). The earthquakes that are now taking place in north Askja volcano appear to be mostly magma related earthquakes. The strongest earthquake so far did happen today and had the size ML2.5 with the depth of 0.1 km. The deepest earthquake so far took also place today and had the depth of 19,6 km. It had the size ML1.4.

However earthquakes with the depth of 22 km has been recorded close to Herðubreiðartögl. Few days ago a tornillo earthquakes (most likely the case now. But yet unconfirmed from my point of view) started too appear in Askja volcano. But that means that magma is on the move in Askja volcano. Currently this might also be the case with the earthquake activity east of Askja volcano. But at this moment it is a bit more unclear what the activity east of Askja volcano means. But it is also possible that magma is also pushing east from Askja volcano. But so far earthquake activity east of Askja volcano has been different then from the earthquake activity north of Askja volcano. But it has not been focuesed on a single spot like the earthquake activity in north part of Askja volcano system.

It is unclear at this moment how this is going to evolve in the long term. But no reports of increased hydrothermal activity have so far appeared in the news. Currently the activity is rather low, so a eruption is not yet imminent in Askja volcano. But that might change without any warning at all at any time.


Current Askja volcano earthquake activity. Click on this picture for full resolution. Picture is from Icelandic Met Office web site. Copyright of this picture belongs too them.

Due to distance. I do not record any small earthquakes from Askja volcano. But they need to be larger then ML3.0 to appear on my geophone network.

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Overview of the Askja volcano earthquakes

This is just a short overview of the Askja volcano earthquakes that have been taking place over the past few weeks. I do not at this have a good picture of what is happening in Askja volcano.

In Week 15 earthquake activity started north of Askja volcano. This activity have been growing since then, with considerable difference between Week 16 and Week 17. Currently the earthquake activity is ongoing. It is not clear if this earthquake activity has slowed down or not. Many of the earthquakes that are taking place north of Askja volcano are shallow. But most of the earthquakes are happening on a depth from 1 km and up to 0.0 km. I am currently unclear on why the activity is so shallows as seems to be the case.

A second set of earthquakes have also been taking place in Askja volcano system. But this earthquakes are taking place east of main Askja volcano. But Askja volcano fissure system goes east and then north from the main volcano. It also goes several km south of main Askja volcano. But that area has not seen any activity so far. While the activity east of Askja volcano is not clustered as it is north of it. It is showing many of the same signs as the earthquakes north of Askja volcano. They are shallows with most of the earthquakes taking place in less then 1 km depth. As before I am not sure why the earthquakes are taking place on less then 1 km depth. But one idea for both the earthquakes north and east of Askja volcano is that there is magma pushing up the bedrock north and east of Askja volcano. But does not at this time have the power to break up trough the crust and start a eruption. Only one deep earthquake has so far been recored, it was on a 22,8 km depth. The location of this earthquake was not far from Herðubreiðartöglum mountains.

Due to lack of GPS data it is hard to see any deflation or deformation in Askja volcano. But it has been known since last year (2010) that Askja volcano has started to prepare for a eruption. But it remains unclear how long it is until Askja volcano is fully ready for a eruption. Last eruptions that took place in Askja volcano where in the years 1961, 1938, 1926, 1924, 1923. More on Askja volcano eruption history here (GVP web page).

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Hekla volcano earthquake last night

Last night at 21:39 UTC there was a ML0.7 earthquake in Hekla volcano. Depth of this earthquake was 1.3 km. It is unclear if this earthquake is a pre-event before a eruption starts. But few years ago there was a earthquke in Hekla volcano. But no eruption did happen that time around.


Hekla earthquake. Click on the picture too see it in full resolution. This picture is released under Creative Common License, see top link for more information.

This is a picture of the earthquake. The distance was 16.8 km from my geophone to the location of the earthquake. My geophone is close to Hekla volcano and because of that it is really sensitive to any activity that takes place in Hekla volcano (given good weather).

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About the earthquakes north of Askja volcano

The earthquakes that are now taking place north of Askja volcano are interesting for many reasons. One of the biggest reason why this earthquakes are interesting is the fact how shallow they are. But it is also interesting on how small the area the earthquakes are taking place on.

This earthquake activity did start in Week 15 with one earthquake. In Week 16 the activity had grown up to few earthquakes. In Week 17 (current) the activity has continued to grow in this area. This activity currently stands out in the earthquake activity around Askja volcano.

While it is common for Icelandic volcanoes to erupt from a central vent. It is also common for Icelandic volcanoes too erupt from fissures (like Fimmvörðuháls Eruption 2010). One of the clues to this type of eruption close to a central volcano is a earthquake activity. It is my opinion that this earthquake activity qualifies as pre-activity for a fissure eruption in the area of Askja volcano. But if anything happens soon is a different question and it is impossible to predict for now. It is however sure that before such eruption the earthquake activity in this area needs to increase a lot more from the current levels of earthquake activity that are being seen today.

Currently no eruption is immanent in Askja volcano.

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Interesting earthquakes north of Askja volcano

There is a interesting cluster of earthquakes north of Askja volcano. What is most interesting is the fact that this earthquakes are shallow This cluster of earthquakes is most interesting for the fact that it is shallow. The depth of the earthquakes is from 8.4 km and up to 0.1 km (~100 meters). This suggests that this is a dike intrusion is making. But appears to be growing slowly (a bit unclear at the moment however). But at this time it is impossible to know if this possible dike intrusion makes it too the surface or not.

History tells that it is not unclear for Askja volcano to erupt in small fissures. But that last happened in the Askja eruption in the year 1961.

Currently it is unclear what is going on north of Askja volcano. But this is for sure evolving into something in my opinion. But the question remains how long this is going to take. But this process has already been ongoing now for about 14 months and counting.

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Interesting earthquakes 20 km WSW of Laki in Eldgjá volcano canyon (Katla volcano fissure system)

There are interesting earthquakes about 20 km WSW of Laki. The locations of the earthquakes suggests strongly that they belong to Katla volcano fissure system. Last eruption in this area took place around the year 934. When the Eldgjá volcano canyon was formed. That eruption did destroy a older volcano canyon located in this same area (lava flows volcano ash did fill up that canyon far as I know).

The earthquakes that have been taking place in this area are small. The largest so far has the automatic size of ML1.2, but only ~4 earthquakes have been recorded so far. But what is most interesting about this earthquakes is the depth. The earthquakes that has the best automatic detection by the SIL system has the depth of 0.7 km. But that makes the depth of ~700 meters and that is a shallow earthquake. Given that this area has only fissures and no activate volcanoes. It is not unheard of in Iceland that a fissure eruption to start with no warning at all. Last time this did happen was in Gjálp eruption in the year 1996. Before that a dike intrusion into the bedrock did manage to get to the surface in Askja eruption in the year 1878, when a 25 km long volcano fissure did open up (small compared to Eldgjá eruption around the year 920).

I do not know what is going on in this area at the moment. As the activity so far has been too small to make any clear picture of it. But Katla volcano is a big volcano and it is not out of volcano league to make a new fissure eruption instead of the regular caldera eruptions under the glacier as Icelanders have gotten used to over the past 1000 years or so. Last time this did happen there are suggestions that there was a also a eruption at the same time in Katla volcano caldera. But that this has only been revealed during research over the past 50 years or so in this area.

I have also noted that there is a small increase in earthquakes inside Katla volcano caldera, not far from Austmannsbunga. But at this moment it is too early too know what it means for sure. There is no eruption is imminent in Katla volcano when this is written. Just too be clear on that fact.

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Quiet scene goes into third week

The quiet scene that has been taking place in Iceland over the last two weeks is still ongoing and is now entering it’s third week. Over the last two week there have been less then 300 earthquakes during a single week. In Iceland that is quiet.

All volcanoes in Iceland have mostly been quiet. But there was a unconfirmed earthquake swarm in Grímsfjall volcano. But due to extremely bad weather it was not observed properly by the SIL network. North of Iceland there also has been a unconfirmed earthquake swarm. This earthquake swarm is somewhere north of Kolbeinsey volcano. But due to distance and bad weather it is unknown how big it was. But the largest earthquakes that have appeared on the SIL network did manage to go up to ML3.0 in size. But that is mostly a underestimate on the size of this event. But underestimate on a earthquake size happens when it is far from SIL network and not properly recorded due that.

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Update on the crack in Þingvellir (Thingvellir), Almannagjá fissure

Tonight Rúv did have a news about the fissure that did open up in Þingvellir (Thingvellir) few weeks ago. Now scientists have started to explore this new fissure. So far they have measured that it is about 10 meters deep. It is still unclear how long it is. The current theory is that this new fissure started to open up after the Mw6.8 and Mw6.7 earthquakes in SISZ in the year 2000, or the Mw6.3 earthquake in the year 2008. But that is however unclear at this time.

What appears also to have happened is that ground water have cleaned out loose material in this new fissure. This might possibly have deepened the fissure. But this aspect of this new fissure is still a bit unclear one. But what is the most amazing thing is that the road has not started to collapse earlier then it did. Due how big this new fissure appears to be.

News on Rúv about this. Use Google translate at own risk, as Google does not know what Icelanders are saying.

Furðulegt að ekki hafi hrunið fyrr (Icelandic, video (Windows Media Video), picture, Rúv.is)

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Few earthquakes in Iceland, interesting events at Kverkfjöll volcano

Currently it is quiet in Iceland when it comes to earthquakes. It is also quiet in Icelandic volcanoes. As no volcano shows clear signs that is about to start erupting. But in this quiet period it is easy to miss the earthquake signs that appear in Icelandic volcanoes.

A volcano named Kverkfjöll has been showing increased signs of unrest over the past few years. So far the largest earthquake swarm took place few years ago. When a cluster of ML2.5 to ML3.5 earthquake took place in it. But since then it has been rather quite. But it is my opinion that Kverkfjöll volcano are on the path to a eruption. But so far it is unclear how and when it might take place. As Kverkfjöll volcano is continues to be a rather quiet volcano, even it is showing slightly higher activity then compared over the last few years. A better SIL network in this are accounts for some of the few earthquakes. But not all of them far as I can tell. In the last 48 hours there have been two earthquakes at rather uncommon place in Kverkfjöll volcano. Both events where small, less then mag 2.0 in size. But those events are part of a pattern that did start in Week 12 of 2011. But even it doesn’t look like a lot. There has been continues activity in Kverkfjöll volcano over the past few weeks and this activity appears to be continuing. I am going to write a better post about it later, when I have better picture of what is going on in Kverkfjöll volcano.

Last earthquake swarm that was in the larger size took place in October 2010. My review of it can be found here, Kverkfjöll volcano shows sign of activity (2010).

Other then this it remains quiet in Iceland. That is why I don’t have a lot too write about at the moment.

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Quiet time continues in Iceland

The quiet times that have been ongoing in Iceland for the past few weeks continue. It has been been my experience over the past few years that when this type of long quiet happens. Usually there is a medium to large event that follows it. Sometimes it is volcanic. But in most cases it is a medium (Mb5.0+) sized earthquake that follows it.

But while the quiet time continues I am going to write a short story and publish it on Amazon as a e-book. More on that when I set-up a special blog about my story publishing.