Category: Magma

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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.

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New earthquake swarm in El Hierro volcano

During the past few days there has been an earthquake swarm in El Hierro volcano in Canary Islands. Following this earthquake swarm there has been some increase in eruption activity. Resulting in some material reaching the surface of the ocean. The reason for this activity is that new magma is being injected into El Hierro volcano from depth. This magma is pushing the magma that is already there closer to the surface, creating dikes and sills in the rock along the way. This also increases the eruption in already open vents.


The harmonic tremor activity in El Hierro today. Copyright of this picture belongs to IGN.

The largest earthquakes in this swarm have had the size ML2.7 and ML3.4. They have been taking place at the depth of 12 to 15 km, based on early data from IGN.


The ML3.4 earthquake in El Hierro volcano that did happen during the night. Copyright of this picture belongs to IGN.

I am expecting this activity to continue for some time now. As it seems that more magma is coming up from depth. How long that progress is going to last is impossible to know. When it stops, it does so and only then the activity in El Hierro volcano is going to stop.

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Minor dike intrusion into Bárðarbunga volcano and earthquakes deep south of Iceland

Yesterday (03.02.2012) at 10:42 to 10:47 UTC there was an minor dike intrusion into Bárðarbunga volcano. Based on the earthquake activity and the depth that they where on. It seems that they did not go close to the surface. Based on the earthquake pattern, the dike intrusion did only go up to the depth of 12 km. But this dike intrusion did rise up from the depth of 22 km.


The dike intrusion into Bárðarbunga volcano. It can be seen by the dense earthquake swarm in Bárðarbunga volcano. Copyright of this picture belongs to IMO.

It is hard to know what this means. But it is for sure an clear sign of more activity in Bárðarbunga volcano. But this is no clear sign that an eruption might be about to take place in the nearby future.

Reykjanes Ridge

Yesterday (03.02.2012) there was an earthquake swarm deep south of Iceland. This earthquake swarm was located on the Reykjanes Ridge. It is impossible to know for sure what was going on at this location due to distance from land. But the average distance of this earthquake swarm is about 450 km south of Eldeyjarboða on the Reykjanes Ridge. The recorded size of this earthquake swarm was from ML3.1 to ML3.3. But that is most likely an underestimate of the earthquake size due to distance from the SIL network.


The star mark the earthquakes. Copyright of this picture belongs to IMO.

Other then this it has been quiet in Iceland. But that has more to due with storms and bad weather. But it has also been quiet in Iceland during the past few weeks. It might continue like that for some time now. When this ends is impossible to know for sure.

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Earthquake swarm in Katla volcano caldera

This morning there was an earthquake swarm in Katla volcano. This is the first earthquake swarm of the year 2012. This earthquake swarm is most likely created by an dike intrusion. Based on how dense the earthquake swarm appears to be. But that is often an sign of an dike intrusion in an volcano. How this earthquake swarm is going to evolve over the next few hours impossible to know for sure. That depends on what the magma is going to do that is creating this earthquake swarm.


The earthquake swarm in Katla volcano. It is dense as can be on this picture from Iceland Meteorological Office. Copyright of this picture belongs to Iceland Meteorological Office.

The earthquakes can be seen on my geophone web page here (English). The geophone at Skeiðflöt is going to go up this week. So all activity in Katla volcano is going to appear more clearly following that. Sadly. No high resolution of the earthquakes that take place is not going to be available until I move back to Denmark. As my main earthquake computer is offline and is going to be so until that time.

I am going to post updates to this if anything more happens. But it might take a while as I am travelling today to Reykjavík area and tomorrow I am going to Skeiðflöt tomorrow.

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Etna volcano prepares for new eruption

According to web cam images and images on the internet of Etna volcano. It seems that Etna volcano is preparing for an new small eruption. When and how big this eruption is going to be is impossible to know for sure. But ash emission have already started in the crater that is most likley going to erupt.

I am going to update this blog post with more details if I can get them.

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Minor earthquake swarm in El Hierro volcano

After the eruption ended in El Hierro volcano it seems that minor magma dike intrusions have been taking place. This magma intrusions so far appears to be deep and not big. Given the depth and the size of the earthquakes that are currently taking place. This also suggests that new magma continues to flow into El Hierro volcano. But that flow might be at slower rate then it was early in the year 2011 before the eruption started. The largest earthquake in this swarm had the size ML2.8 with the depth of 12 km. Based on automatic data.


The current earthquake activity in El Hierro volcano. The earthquake swarm in question was small in size. Copyright of this picture belongs to IGN.


The earthquake activity appears clearly on this picture. The highest peak is the ML2.8 earthquake. Copyright of this picture belongs to IGN.

It is hard to know for sure what this means for future eruption events. Before the earthquake swarm today there was an small eruption somewhere in El Hierro volcano. It can be seen by the harmonic tremor levels. But this event was small, a lot smaller then earlier events. All that can be done is to wait and see what happens next in El Hierro volcano.

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Random minor eruptions in El Hierro volcano

It seems that the main eruption is over in El Hierro volcano, for now anyway. For the moment there are minor eruptions taking place in El Hierro volcano. This minor eruptions happen at random times and between them nothing is happening. This is clear by the harmonic tremor data from the sensors that are on the El Hierro Island it self.

This type of behavior is not a big surprise. I fully expected this to happen when this eruption started. The main risk now is that new vents might open up in new places without any warning at all. This seems to have already have happened to some extend. As I have been getting unconfirmed reports that new vents have opened up in this new eruption episodes that have only lasted for few hours. So far this new vents have not opened up on land. But this pattern of eruption increases the risk of that significantly. As magma appears to looking for a way out. But does not find the way out that last, or does not have the pressure to maintain an new vent open for long period of time. The vent that erupted the longest is estimated to be around 125 meter below the surface. So it has been guessed that its above 750 meters high (this is unconfirmed).


Harmonic tremor and lows in El Hierro volcano today. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).


The harmonic tremor activity yesterday (23.01.2012). As can be seen the activity starts, then stops again. This means that new vents are opening up again. Or that the older vents are opening up and starting to erupt again before stopping. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).


The activity on 22.01.2012. This as same in the past two days. Activity start before stopping again. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).

As for what happens in El Hierro volcano in the next weeks to months. It is close to impossible to know for sure what happens. As what happens next depends on the magma flowing into El Hierro volcano. It seems that this eruption is not over. Even if it continues with short breaks between eruption events.


Picture of the activity today (24.01.2012). I got this picture by email. Click on the picture for full size. Copyright holder of this picture wish to remain anonymous. Used with permission.

This picture clearly shows the active area today. There is also an highly active hydro-thermal area where the eruption took place, or have been taking place. There is also some chance of dike intrusions in this area creating new hydro-thermal areas. But dike intrusions can take place without any earthquake activity. If there is an earthquake activity, it does not need to have high amount of earthquake activity. Harmonic tremor can and often increases if an dike intrusion is taking place.

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El Hierro volcano eruptions ends (again)

Based on the harmonic tremor data in the past few hours it seems that the eruption in El Hierro volcano has ended again. How long or if the eruption has really ended now is impossible to know at the moment. However it is clear based on the tremor activity that all eruption activity has ended and it did so suddenly and after sharp increase in activity several hours before that.


The activity in El Hierro volcano today. Notice the spikes when the eruption suddenly gains energy and how fast it dies out based on the tremor data. Copyright of this image belongs to IGN (Instituto Geográfico Nacional).

Even if the eruption has ended. For the moment anyway. The area where the eruption took place is going to have hydro thermal activity for several months to comes, and up to many years if there are any shallow dike intrusions in the base of El Hierro volcano (and Island). I do not yet know if the eruption has ended, or if this is just an brake in the current eruption cycle. But next few hours to days are going to make it clear if this is an break or not. But I would not be surprised if the eruption started again at the same location, or an new one. As this is shield volcano and there eruption pattern often have breaks in them for shorter and longer periods of time.

Update 1: It has been sad that the graph has once again been re-scaled. To what size I do not know for sure. But in an comment on Facebook it was sad to be around -36dB. If that is the case. I am wrongly interpreting the data. Because of that. I have no idea what is going on in El Hierro volcano at the moment.

Update 2: It seems that activity has renewed again in El Hierro volcano. It started around 04:06 UTC and lasted until around 10:00 UTC. Then it started again at 16:00 UTC and is currently ongoing. This is now an eruption that happens in episodes. That means there are going to be longer and shorter breaks between eruptions in El Hierro volcano.


Activity in El Hierro volcano today. The increase in harmonic tremor marks the start of new eruption in El Hierro volcano. Copyright of this image belongs to IGN (Instituto Geográfico Nacional).

Blog post updated at 00:50 UTC on 20.01.2012.
Blog post updated at 19:31 UTC on 20.01.2012.