Category: Volcano

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Three earthquakes in Hekla volcano

During the night there where three earthquakes in Hekla volcano. All of the earthquakes where small with the magnitude of 0.6 up to 0.9. Depth of this earthquakes was on the range of 10.7 and down to 11.8 km. No other activity has followed this earthquakes in Hekla volcano since this earthquakes took place.

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The earthquakes in Hekla volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Currently there are no signs of volcano eruptions in Hekla volcano. If that changes I am going to write about it. But for now Hekla volcano is as quiet as it has been since the year 2000. When last eruption took place.

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Deep earthquake swarm in Tungafellsjökull volcano

Today (03.03.2013) between 13:19 UTC and to 13:21 UTC a deep earthquake swarm took place in a volcano named Tungnafellsjökull. This was a minor earthquake swarm, with the largest earthquake having magnitude 1.4. But it is the depth that is important here. The depth was most at 28 km, with the shallowest earthquake having the depth 18.7 km. This suggest magma intrusion into the volcano at depth. A pattern that was seen during the Eyjafjallajökull volcano eruption as an example.

For the past few months. Tungnafellsjökull volcano has been having swarms of earthquakes. All of them small, but many of them above 2.0 in magnitude. But so far none above magnitude 3.0. While earthquake activity has remained low in Tungnafellsjökull volcano I find that events are speeding up there in the past few months. With the terms that more earthquakes are being detected in this volcano and now at more depth. I find this worrying and also interesting. This volcano is far from any populated area, so any damage resulting for an eruption in it should be minimal. It also has no glacier to speak of. There is going to be a bad weather in Iceland until Friday (according to the weather forecast at the moment), so detecting any small earthquakes in this area might be limited by it.

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The red dots show the earthquake activity in Tungnafellsjökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

It is too early to know what happens in Tungafellsjökull volcano. It is also important to note that Tungnafelljökull volcano has never erupted in historical times. This makes figuring out what happens next in it more difficult then ever. This activity might not mean an eruption is imminent. But at the moment I cannot rule one out just yet. It is clear that more activity is going to be needed before the picture of what is taking place in Tungnafellsjökull volcano gets clearer.

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Interesting earthquake swarm in Katla volcano

There is a interesting earthquake activity taking place in south part of Katla volcano south caldera rim. This activity has been ongoing since in July 2011 after the minor eruption that year. The most logical reason for this earthquake activity is that in this location is a magma dike on the move. If that is actually the case is impossible to know for now. But this activity remains interesting for many reasons.

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Earthquake activity in south Katla volcano caldera rim. This earthquakes are all small earthquakes. Copyright of this image belongs to Icelandic Meteorological Office.

This earthquakes are small. Most of them are on the magnitude range of 0.0 to 0.5. There depth is around 1 km up to 0.1 km (around 100 meters). So whatever is creating this earthquake activity is already shallow up in the crust. I do not know if there is going to be a eruption in this area. That is just a wait and see as always with volcanoes. But it is my estimate that (based on older data) this might mean there is more activity going to take place in Katla volcano soon. But that might fail. Since volcanoes are by nature unpredictable. So there are no assurances about what is going to happen next in Katla volcano.

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Earthquake swarm east of Grímsey (TFZ) and in Grímsfjall volcano fissure swarm

Currently there is a minor earthquake swarm east of Grímsey Island in the Tjörnes Fracture Zone. So far the largest earthquake has had the magnitude of 2.9 according to Icelandic Meteorological Office reviewed earthquake overview. Earthquake swarms are common in this area of TFZ.

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Earthquake activity in TFZ today. Copyright of this image belongs to Icelandic Meteorological Office.

Grímsfjall and Hamarinn volcanoes

Some internesting earthquake activity is now taking place in Grímsfjall volcano (outside the main volcano). This earthquake activity is in the fissure swarm that extents away from Grímsfjall volcano in the direction of Katla volcano fissure swarm. There has also been interesting earthquake activity taking place in Hamarinn volcano (no GVP page). But Hamarinn volcano last had a minor eruption in July of the year 2011. So far nothing suggests anything of volcanic nature is about to take place.

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Earthquake activity in Grímsfjall volcano system today. Along with earthquake activity in Hamarinn volcano. Copyright of this image belongs to Icelandic Meteorological Office.

At the moment it appears that nothing besides earthquakes is going to take place in Grímsfjall volcano. But it hard to be sure given how often Grímsfjall volcano erupts. I do not yet have enough data on what is happening in Hamarinn volcano to say what is taking place there. So for now. It must just be observed.

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Earthquake swarm in Torfajökull volcano

Today (16.02.2013) at 15:11 UTC an earthquake swarm started in Torfajökull volcano. This is so far small earthquake swarm. With largest earthquake only having magnitude 2.6 (automatic result). Depth of this earthquake swarm is around 2 to 4 km. This earthquake swarm is taking place inside the volcano. So they might be magma related. But it is hard to know that for sure at the moment. This might just be normal tectonic earthquakes in this area. Earthquakes are common in this volcano. But major swarm activity does not seem to be for some reason.

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Earthquake activity in Torfajökull volcano. The earthquakes are the red dots on this image. Copyright of this image belongs to Icelandic Meteorological Office.

It is hard to know exactly what happens next. But most often the earthquake activity in Torfajökull volcano stops after few hours. Last documented eruption in Torfajökull volcano took place in the year 1477 according to Global volcanism program (GVP). This earthquake activity appears clearly on my Heklubyggð geophone and Skeiðflöt geophone. The web site for my webicorders can be found here.

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Interesting earthquakes close to Tungafellsjökull volcano

There is some interesting earthquake activity taking place close to Tungnafellsjökull volcano. This earthquake activity started last year in this area. It is unclear what is happening. But this might just be normal tectonic activity. The earthquakes are on the depth of around 4 km.


Earthquake activity close to Tungafellsjökull. Copyright of this image belongs to Icelandic Meteorological Office.

I am not sure if earthquake activity is going to continue in this area. As earthquake activity is intermittent in this area. The Torfajökull volcano however remains silent. But this activity is interesting. Since this area normally does not have earthquake, since it remains outside the main fault zones. But it is still inside the main rift zone in Iceland.

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Magnitude 3.8 earthquake in Bárðarbunga volcano

During the night at 04:50 UTC there was an earthquake with the magnitude 3.8 in Bárðarbunga volcano. This appears to be a minor dike intrusions into Bárðarbunga volcano. This happens regularly in Bárðarbunga volcano. Often resulting in a lot larger earthquakes then current earthquake swarm that is taking place in Bárðarbunga volcano.


Earthquake activity in Bárðarbunga volcano. The star is the magnitude 3.8 earthquake. Copyright of this image belongs to Icelandic Meteorological Office.

It is impossible to know what is going on in Bárðarbunga volcano. But there is no risk for volcano eruption for now. Even if there is possibility of minor dike intrusion taking place in Bárðarbunga volcano at the moment. I am not expecting anything more at the moment. But more earthquakes can not be ruled out, as Bárðarbunga volcano is a earthquake active volcano.

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Picture and video of Eyjafjallajökull volcano

Here is a picture of Eyjafjallajökull volcano that I took in December 2012. This is not a good picture. But that is mostly down to bad weather and strong wind at the time.


Click on the image for full size. This image is released under Creative Commons licence. Please see the CC Licence page for more details on this licence.

Here is a video that I took from this same area. It shows how bad the weather was.

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Comparison of volcano eruptions

When there is nothing going on in Iceland. It is good to prepare for the future by checking out what has happened in the past. Here is a comparison of harmonic tremor data from few past eruptions. I only have limited set of data to work with here.

Grímsfjall volcano eruptions 2004 and 2011

Harmonic tremor indicates how strong the eruption is when it is happening. This is clearly visible on the harmonic tremor plots from the Grímsfjall volcano eruptions in the year 2004 and compared to the eruption in Grímsfjall volcano eruption in the year 2011.


Harmonic tremor in Grímsfjall volcano eruption in the year 2004. Copyright of this image belongs to Icelandic Meteorological Office.

This harmonic tremor plot is from the early start of the eruption. It clearly shows when the eruption starts and how it progressed during it’s first few hours.


Here is the volcano eruption start in Grímsfjall volcano on 23. May 2011. This is the start of the eruption. It clearly shows the difference from the eruption that took place in the year 2004. Both is that starts sharper. But is also a lot more powerful then the eruption in the year 2004. Copyright of this image belongs to Icelandic Meteorological Office.

Eyjafjallajökull volcano and Katla volcano

Sometimes it is useful to compare two eruptions of two different volcanoes. This is useful when you really don’t have anything else to compare with.


Harmonic tremor in Eyjafjallajökull volcano eruption back in the year 2010. This is from the second phase of the eruption. But I seems to have misplaced or not saved harmonic tremor data from the first phase of the eruption (at least I cannot find them for the moment). Copyright of this image belongs to Icelandic Meteorological Office.


Harmonic tremor connected to a minor eruption in Katla volcano in July 2011. This eruption was minor. But created a flood that took out a bridge. Copyright of this image belongs to Icelandic Meteorological Office.


Diffrent SIL stations from the same minor eruption in Katla volcano in July 2011. This clearly shows that this minor eruption in Katla volcano was possibly larger then eruption in Eyjafjallajökull volcano year earlier (2010). But it did not manage to break the ice of Mýrdalsjökull glacier. Copyright of this image belongs to Icelandic Meteorological Office.

Past data show and are useful to learn what happens in a volcano. For this reason I now save important information on what is happening in a volcano. So I can compare it with future activity when it takes place.

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Magnitude 3.3 earthquake in Bárðarbunga volcano during the night

At 02:55 UTC today (18.12.2012) there was a magnitude 3.3 earthquake in Bárðarbunga volcano system. Earthquakes are common in this area so this activity is no surprise. Origins of this earthquakes are due to tectonic movements in the area. Not magma related changes.


Green star marks the magnitude 3.3 earthquake in Bárðarbunga volcano system. Copyright of this image belongs to Icelandic Meteorological Office.

Aftershocks have followed this earthquake. So far the largest one got the magnitude 2.2. More earthquake activity can be expected in this area. But that is normal and not unexpected.