New measurements of Eyjafjallajökull volcano crater

There is a short news piece about Eyjafjallajökull volcano on the news web site Morgunblaðið (mbl.is). It is about recent trip that geologist took to Eyjafjallajökull volcano. They where monitoring and during measurement of the crater that did form on top of Eyjafjallajökull volcano during the eruption in the year 2010.

According to the news, the crater lake in Eyjafjallajökull volcano is now frozen and there is already 10 meter thick snow layer in the crater. While the lake is cold it is still dangerous do go down into it and people are advanced against to do so. Due to carbon monoxide that is on bottom the crater. While the bottom of the crater is cold, the same cannot be sad about the crater walls. But they are still steaming and the temperature there is from 70C and up to 95C not far below the surface. So this area continues to be dangerous to people and travelling into it should be done with care and not without an experienced tour guide.

The reason why they did go to this trip today was too estimate the area before more detailed measurements are done this summer.

News from Morgunblaðið with picture can be found here.

Fóru ofan í gíginn (mbl.is, Icelandic, pictures)

Blog post updated at 02:24 CEST on 14. May 2011.

Deep earthquake in Herðurbreiðarfjöll volcano (Askja volcano fissure swarm)

Today at 06:57 UTC in Iceland there was a ML0.2 earthquake east of Herðurbreiðarfjöll volcano. While the size of this earthquake is really small. It is the depth that is interesting in this case. The depth of this earthquake was at 25,7 km depth. This is a interesting depth given the increase in earthquake activity in Askja volcano.

According to my geological map (a rather new one) the mountain named Herðubreiðarfjöll is a volcano that is inside Askja volcano fissure swarm. A common thing that happens in Iceland. This area has many active fault lines and has erupted in modern time. But I do not know when this volcano last erupted, as there are no information on Herðurbreiðarfjöll volcano activity in the GVP database and I have not found anything useful on the internet about this volcano.

Earthquake activity continues in Askja volcano. But at slower rate then before. Other then this, it is quiet in Iceland as it has been for the past few weeks.

The magma below Upptyppingar tuff mountains

Upptyppingar are a tuff mountains in the east highlands in Iceland. There formation is contributed to a sub-glacier eruption in this area around 12.000 years ago. A second older sub-glacier eruption feature is also present in this area, it is called Álftadalsdyngja. It is believed that it did form around 700.000 years ago in a basalt eruption in this area. Upptyppingar and Álftadalsdyngja are both inside Kverkfjöll volcano fissure swarm.


Map of the area. Copyright of this picture belongs to how created it. Author unknown. Picture is from here.

In the year 2007 (Week 50) a earthquake swarms started to appear in Upptyppingar area. Earthquake activity in Upptyppingar area have continued since then. With total number of earthquakes in this area since the year 2007 is something over 6000 total. The reason why earthquakes are happening in this location is because magma is pushing up trough the crust in this area. This has been confirmed by GPS measurements since the year 2007.

It is my opinion that increased activity in Askja volcano might trigger a eruption in Upptyppingar area or in nearby area. As the risk of dike intrusion from Askja volcano into the Upptyppingar magma sill might trigger a large fissure type of event in this area. This is just speculation based on observed data. So please take note of that fact. The reason why I fear dike intrusion from Askja volcano is due to the changes that Upptyppingar magma has created in the nearby crust. But if this happens depends on how Askja volcano eruptions are going to behave in the future.

Here are some scientific data on Upptyppingar and the magma that has been collecting at 15 km depth below Upptyppingar mountains since the year 2007.

EARTHQUAKE SWARMS AT UPPTYPPINGAR, NORTH-EAST ICELAND: A SIGN OF MAGMA INTRUSION? (pdf, study)


Location of the earthquakes since the year 2007. Copyright of this picture belongs to Icelandic Met Office. Picture is from here.


Depth of the earthquakes in the year 2007. As can be seen, the magma moved upwards with time. Copyright of this picture belongs to how created it. Author unknown. Picture is from here.


Estimated location of the magma below Upptyppingar mountain. This location is based on earthquakes and other measurements. Copyright of this picture belongs to how created it. Author unknown. Picture is from here.

What happens with Upptyppingar is now just a question of waiting and seeing. But there is also a good chance that this magma is never going to reach the surface in a eruption and is just going to cool down there and form a basalt dike that is going to be exposed in few million years when the weather and ice remove the rocks on top of it.

Earthquake in Askja volcano last night

Here is a picture of a earthquake that took place in Askja volcano last night. This earthquake was bearly visable on my geophone close to Hekla volcano. From this data it is clear that the earthquakes are created by magma movements inside Askja volcano. But the earthquake swarm is taking place on the edge of Askja volcano main system. It is not happening outside as it might appear.

It is also worth pointing out that not all of Askja volcano earthquakes might appear on the automatic SIL system. But most of them should do so. As Askja volcano is remote and in a unpopulated area there should not be any damage from a eruption. The only damage might happen if there is a eruption in Askja caldera lake due to ash cloud that might form.


Askja volcano earthquake. This is low pass filtered at 1Hz. This image is released under Creative Commons License, see top link for more information. Click on this picture for full resolution.

This earthquake has magma signature from the looks of the earthquake signal. But due to distance it is hard to be sure on that.

When this is written a tremor pulse appears to be starting in Askja volcano. But this might also be a swarm of micro earthquakes taking place in Askja volcano without the earthquakes appearing on the automatic SIL system. At this point it is hard to know for sure, as this activity is new.


Locations of the earthquakes in relations to the Askja volcano system. As can be seen on this map from Icelandic Met Office, the earthquakes are clearly inside Askja volcano. Even if they are not at the main caldera. Picture is from Icelandic Met Office web site. Copyright of this picture belongs to Icelandic Met Office.

Blog post updated at 16:37 UTC on 5 May 2011. Picture is added.

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.

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).

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).

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.

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.

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.