Category: Hydrothermal

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Sharp increase in eruption activity from El Hierro volcano

This is a short update on El Hierro volcano.

There has been a increase in harmonic tremor activity from El Hierro volcano. This suggest that new vent or vents might be opening up in El Hierro volcano. But this type of eruption pattern is to be expected from a fissure eruption. Like the one that is currently taking place in El Hierro volcano.


The harmonic tremor jump in El Hierro volcano at 16:06 UTC. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).

There are also some explosions that can be seen on this tremor chart. But they form spikes that can be spotted if looked closely. Is is now also possible to monitor the eruption via web cam located on El Hierro Island. That web cam can be found here.

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Update on the eruption in El Hierro volcano on 9 November, 2011

Short note on comments: This is a short notice on comments. This blog has been getting a spam flood for the past few days. During the past 2 days or so there have been over 300+ spam comments that my spam filter has captured. This makes it ever so hard to find real comments that go into the spam box by accident. If your comment disappears for no reason after it has been posted. Then the spam filter has captured it. Please do not re-post it, as then following comments are just going to go into the spam box too. I have to manually un-check them as spam and approve them. So if you post three comments with the same link, I am going to clear the three comments with the same link. But given the amount of spam that this blog is getting there is always a risk that comment is going to get lost and permanently deleted.

It is also important that if you get “comment is held for moderation” that you do not re-post what you are commenting on. As the comment is going to wait in the moderation until I clear it. I am not always around to check for this, so it might take few hours or more until I approve the comment/s.
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The eruption in El Hierro volcano is ongoing and does not appear to show any signs of ending. However the strength of the eruption has dropped a bit during the past two days. But this was to be expected, since this is a fissure eruption and it has mostly been erupting from the same vents during the past four weeks.

It has become a bit difficult to get accurate information on what is going on El Hierro Island. So I am not going to speculate on that. But from what I can gather it seems that dangerous gas level has been detected on the ground. But the reports that I am reading are bit unclear on this. This has also been mentioned in comments on this blog.


The harmonic tremor from the eruption in El Hierro volcano at 15:23 UTC on 9 November, 2011. Copyright of this picture belongs to IGN.

As can be seen on this tremor plot the harmonic tremor in the eruption is dropping. Explosions that have taken place are also clear on this tremor plot. That might be because the eruption vent is getting smaller, therefor less magma is being push out the erupting vent. Or the currently erupting vent might be closing up. As so often happens with fissure type eruptions. If that happens does not mean that this eruption cycle is over. It just means that the current eruption vent has closed up. New fissures are most likely to open up in coming weeks as the eruption goes on. Where and when it impossible to know for sure.

Earthquake activity continues in north part of El Hierro volcano. This are most likely dike intrusions into the bed rock there. So earthquake activity should be expected to continue north west of the town Frontera. If a dike intrusion manages to find a path to the surface in this area there is going to be a eruption and earthquake activity should drop following that. But until and if that happens there are going to be earthquakes. There is also chance of hydrothermal activity to show up in this area if a dike intrusion gets shallow into the bed rock. But is not go up from the ground and start a eruption. This might also be the reason why some part of El Hierro Island are experiencing high levels of toxic gas for the moment.

I am going to post more on the eruption in El Hierro volcano as I know more what is going on.

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Harmonic tremor pulse in Katla volcano

This just started few moments ago so I waiting on how this develops. But there is a harmonic tremor spike in Katla volcano.

The harmonic tremor in Katla volcano started with a small earthquake swarm. This is more then just minor event it seems. But at this moment it is hard to know how this is going to develop. But next few hours are going to give clear picture of what is going on in Katla volcano. There is a bad weather in the area, but that makes the observation of what is going on more difficult then in good weather.


The earthquake swarm in Katla volcano. Copyright of this picture belongs to Iceland Met Office.


Harmonic tremor pulse in Katla volcano at 16:00 UTC on 7 November, 2011. Copyright of this picture belongs to Iceland Met Office.


Harmonic tremor pulse in Katla volcano at 16:00 UTC on 7 November, 2011. Copyright of this picture belongs to Iceland Met Office.


Harmonic tremor pulse in Katla volcano at 16:16 UTC on 7 November, 2011. Copyright of this picture belongs to Iceland Met Office.

What happens next is impossible to know for sure. But watching what is happening in Katla volcano is the only thing that can be done for the moment. No more earthquakes have happened so far in Katla volcano (at the time when I write this). The harmonic tremor pulse was detected up to Skrokkalda SIL station. But also on Grímsfjall SIL station. There is a harmonic tremor pulse also taking place in Hamarinn volcano, more on in a little bit. This harmonic tremor pulse is because of dike intrusion is taking place in Katla volcano. It is impossible to know how big it is currently.

Blog post updated at 16:26 UTC on 7 November, 2011.

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General update for Katla volcano and El Hierro voclano

This is a general update for Katla volcano and El Hierro volcano.

Katla volcano, Iceland

During the weekend there was a minor dike intrusion into Katla volcano caldera. The largest earthquake in this earthquake swarm was a ML2.1 with the depth of 1.4km. This is among the smallest earthquake swarms in Katla volcano since activity started to increase after the small eruption in July 2011. The reason for this earthquake swarms in Katla volcano are dike intrusions (wiki). Sometimes following this are small glacier floods from Mýrdalsjökull glacier that is on top of the caldera. But that does not seems to have this time around, or the last time there was a dike intrusion in Katla volcano (few weeks ago).


The earthquake activity in Katla volcano during the weekend. Copyright of this picture belongs to Icelandic Met Office.

El Hierro volcano, Canary Islands, Spain

The eruption in El Hierro volcano continues as it has been doing for the past four weeks (almost). But the chance of a new island forming has grown somewhat in the past few days. The main reason for that is that eruption did gain some strength during the past two weeks. The increased strength in the eruption was due to a new injection of magma into El Hierro volcano. Both at the main magma sill and what seems to be a new magma intrusion into El Hierro at depth. That magma has so far not been able to reach the surface and remains at the depth of 20 km or so. But there also seems to be some dike intrusion activity been taking place in the same area, as more magma is injected under El Hierro volcano North West of the town of Frontera (IGN name information).

For that reason the risk of new eruption vents open up in this area is high in my opinion and is going to remain that during this eruption. But it remains to be seen if a new eruptions vents open up in this area. But that depends on the amount of magma that is currently injecting into El Hierro volcano at depth. It is impossible to know for how long new magma is going to get supplied into El Hierro volcano. But so far this process has been ongoing since July, so that is already five months (or about that) that new magma has been flowing into El Hierro volcano.

The formation of new Island off the coast of El Hierro Island is now a real chance. As the erupting vent has build up close enough to the surface of the water to start the Surtsey Island process. That process in it self is going to take few weeks to complete, at least until the crater no longer gets water into it. When the water can no longer into the crater the eruptions turns to lava fountain eruption. A Hawaiian style of eruption to be exact. That progress is going to remain to the end of eruption. But this is only going to happen if the eruption lasts long enough to build a small Island off the coast of El Hierro Island. So far that remains unseen. However the chance for this to happen is good in my view.

There is also worth noticing that this eruption is a bit variable in eruption strength. This can clearly be seen on the harmonic tremor plots that can be viewed online from El Hierro volcano. This is normal, as the flow of magma from inside El Hierro volcano is not stable and can change suddenly. The risk of new fissures to open up without warning remains high in the area around the current eruption vent is also high. The new fissure have the risk of opening up without any earthquakes and warning. To some extent this has already happened during this eruption. But I am not sure the new eruption vents did stay erupting for a long time. This is however most likely to repeat it self regularly during this eruption.


The harmonic tremor in El Hierro volcano on 7 November, 2011 at 09:32 UTC. Copyright of this picture belongs to Instituto Geográfico Nacional.

Off topic: Small apology

Here is a small apology to my readers. I have been a little bit under the weather in past few weeks. There are many reasons for this. But the biggest one is that my plan to live in Denmark failed this summer. But the chance of me moving back to Denmark has lifted my mood again. But I also found that playing computer games helps me dealing with my current status a bit. Because of this under the weather issue. My blog post have not been that good in my view. For that I want to apology. I can’t promise that this won’t happen again while I am living in Iceland. It is also a factor that the darkest time of the year never goes well with me (Mid October to early March).

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El Hierro volcano enters Surtsey eruption phase

This is a short blog post about latest events.
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Earlier tonight a Surtey eruption started in El Hierro volcano. Before this phase did start there has been increased harmonic tremor on seismometers that are located on El Hierro Island. Volcano ash is to be expected while water can still get into the crater. When the water does no longer get into the crater it is going to stop making volcano ash. The ash plume can go up to 3 to 10 km high, depending on the strength of the eruption. New vents have also been opening up south of town of La Restinga. That means the fissure is still growing, at least that was the case yesterday and earlier today from what I can gather. I am unsure of that has continued or stopped.

Earthquake activity still high north west of the town of Frontera. This suggests that fissure might open up there. But so far that has not happened. I do not think this are earthquakes due to tectonic stress changes due to the eruptions in south El Hierro volcano. But this stress changes are because of the magma injections at depth in El Hierro volcano.


Harmonic tremor from the eruption in El Hierr volcano. It now shows clear signs of explosions (strong ones) and increased eruption activity. Copyright of this picture belongs to Instituto Geográfico Nacional.

If new vents open up closer to the shore there is going to be instant Surtsey eruption activity. But that might only last for a short while the water gets into the crater. There the lava stage is reached much sooner then on the vents that are erupting on more depth at the moment.

I am going to post more updates on this. If I can get more details on what is going on.

Sources:

Renewed Eruptions at El Hierro in the Canary Islands (Eruption blogs)

I also want to thanks reader how email me about the current status of what is going on in El Hierro volcano. My Spanish is weak at the moment.

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Increased eruption activity in El Hierro volcano

I was going to post this yesterday. But I fell a sleep at 17:00 UTC and I didn’t wake up until 03:00 UTC.
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The eruption in El Hierro volcano continues as it has been doing for past few weeks with little change. The first eruption vent that did open south of El Hierro Island has continued to erupt. But so far no Island has formed and it is unclear if it is going to form, as the depth is great in this area. Since yesterday around 06:00 UTC the harmonic tremor has been increasing. But this suggests that new vents have opened up in the south eruption area. I got some pictures of that yesterday in the email. But they did not show anything new in my view. Thanks to the readers how did send me those pictures.

The current fluctuation in the harmonic tremor from El Hierro suggests that magma is on the move in the north part of El Hierro Island. Both off the coast and maybe inland on the Island where earthquakes have been taking place. It is impossible to know how this is going to develop during the next few hours to days. As that depends on the rock structure of El Hierro Island and earlier eruptions.

Earthquake activity

During the past two weeks the earthquake activity have been growing in the North-west part of El Hierro Island. The reason why this is happening is that a new fissure is about to open in this area. As I have mentioned before in earlier blog posts. When and where is impossible to know for sure. The largest earthquake so far took place this morning, it size was ML4.0 with the depth of 20 km. But this is the automatic data from IGN. This pattern of earthquake activity is most likely going to continue during this eruption process in El Hierro volcano. Since the eruption type here is a fissure eruption.

It is worth noting that earthquakes in once place does not mean that the eruption is going to happen in that place. As the magma can travel in dikes all over the El Hierro Island and show it self anywhere on the Island it self. So the general risk is high in my opinion. The only action that can be taken is to be prepared for sudden eruption of new vents on El Hierro Island. Since there is a good amount of magma on the move inside El Hierro volcano.


The harmonic tremor in El Hierro at 08:54 UTC (when picture is saved). The spikes are earthquakes, and harmonic tremor spikes are the “waves” in the harmonic tremor pattern. Copyright of this picture belongs to Instituto Geográfico Nacional.

Update 1:

* When I wrote this blog post. This two earthquakes took place.

1109584 02/11/2011 08:37:11 27.9267 -18.1084 3 1.7 mbLg NW FRONTERA.IHI
1109582 02/11/2011 08:36:00 27.5986 -17.9594 1 1.9 mbLg S EL PINAR.IHI

This are the most shallow earthquakes that I have seen so far. From the depth it is possible a magma has found a clean path to surface in this two areas. Sadly there is no map. So I am not sure where this earthquakes took place in El Hierro volcano.

Update 1b: The earthquake have been revised. Now the depth is 9 km for the ML1.7 and 22km for the ML1.9.

The shallow earthquake.

1109584 02/11/2011 08:37:11 27.9304 -18.1107 9 1.7 mbLg NW FRONTERA.IHI [+]

I am going to post more information when I know more on what is taking place in El Hierro.

Blog post updated at 11:24 UTC on 2 November, 2011

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New earthquake swarm in Katla volcano

When I just think that Katla volcano had gone quiet. It starts a earthquake swarm to proof that I had it wrong.

This earthquake swarm in Katla volcano is not big. But the largest earthquakes where up to ML2.6 in size according to Iceland Met Office web page. This earthquake swarm is located in Katla volcano caldera, in the area that have been most active since July 2011. No harmonic tremor has followed this earthquake swarm.


The earthquakes in Katla volcano today. Copyright of this picture belongs to Iceland Met Office.


The tremor plot of the earthquake from Slysaalda SIL station. Copyright of this picture belongs to Iceland Met Office.


The earthquake swarm on Alftagröf SIL station. Copyright of this picture belongs to Iceland Met Office.


The earthquakes as they did appear on my geophone at Heklubyggð (Hekla volcano). This picture is released under Creative Common Licence. See the Licence page for more details.

This was most likely a small dike intrusion in Katla volcano caldera. But that seems to be the major driving force behind this earthquakes that are currently taking place in Katla volcano caldera. It is hard to know for sure if this earthquake swarm is going to continue or not. But this high earthquake activity in Katla volcano suggests that it is not far away from erupting. But it is impossible to know when a eruption might take place at current time.

Icelandic News about this earthquake swarm.

Smáskjálftar í Mýrdalsjökli (mbl.is, Icelandic)

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Update on Katla volcano earthquake swarm

There has not a lot changed in the past few hours since the earthquake swarm did start in Katla volcano. Eruption has not yet started in Katla volcano and when it might start is still a mistery.

Current map of the earthquake activity.


Current earthquake activity in Katla volcano. Copyright of this picture belongs to Iceland Met Office.

Here are traces from my Heklubyggð geophone. But that is currently the geophone that I have that is closest to Katla volcano. I am collecting donations so I can buy two new geophones. The blog post about that can be found here. I do not expect to have the geophone in place before a eruption starts in Katla volcano this time around. So far the donations are up too 5,410.74 DKK, so I am not far from what I need to collect. I do not have to pay customs of this according to a email I got from the customs office when I did ask about it. But I have too pay 25,5% VAT on this when it gets here. That might be a good amount I think in Icelandic Kronas (ISK).


One of the large earthquakes. This is not the strongest earthquake in the earthquake swarm that took place this morning in Katla volcano. This is also a double earthquake, that is two earthquakes taking place at the almost the same time. That is the reason for the odd looking wave form on this earthquake trace. This picture is released under Creative Commons licence. See Licence web page for more details.


A ML3.0 earthquake that took place in Katla volcano this morning. This picture is released under Creative Commons licence. See Licence web page for more details.


The largest earthquake in the earthquake swarm this morning. Its size was ML3.55 with the depth just short of 1 km. This picture is released under Creative Commons licence. See Licence web page for more details.


A ML2.94 earthquake in Katla volcano this morning. This picture is released under Creative Commons licence. See Licence web page for more details.

So far it has quieted down in Katla volcano. But that does not mean a lot. As magma can go on the move at any time. Without any warning at all. So monitoring Katla volcano is important with that fact in mind. According to Iceland Met Office, this is the largest earthquake swarm in Katla volcano caldera since the year 2002.

I am expecting more strong earthquakes to take place in Katla volcano. But it is impossible to know when a new earthquake swarm might start in Katla volcano and how large and long it is going to last. For the moment, it is just wait and see.

Iceland Met Office has put up a news about this in English. Thanks too the readers how pointed this out!

Earthquake activity in Katla volcano October 2011

Icelandic News about this earthquake swarm.

Snarpasta hrinan í Kötlu frá 2002 (Rúv.is, Icelandic)
Snörp hrina í Mýrdalsjökli í nótt (Rúv.is, Icelandic)
Snörp hrina í Kötlu (Vísir.is, Icelandic)
Sterkir skjálftar undir Mýrdalsjökli (mbl.is, Icelandic)
Um 20 skjálftar yfir 2 stig (mbl.is, Icelandic)

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Large earthquake swarm in Katla volcano

At 02:45 UTC a large earthquake swarm did start in Katla volcano. I do not know if this an start of a eruption in Katla volcano or not. For the moment it is too early to know for sure. I have to wait few more min before that becomes clear on the harmonic tremor plots. The largest earthquake so far according to the automatic SIL systems is a ML3.9 earthquake.


The earthquake swarm in Katla volcano. The second green star is from a fake ML3.3 earthquake from yesterday. Copyright of this picture belongs to Iceland Met Office.


The harmonic tremor plot on Slysaalda SIL station at 03:04 UTC on 5 Október 2011. Copyright of this picture belongs to Iceland Met Office.

It takes a few moments to become clear if Katla volcano is starting a eruption or not. I am going to post updates as this situation changes if I have too.

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Small eruption took place in Katla volcano in July 2011

According to the news on Rúv this evening it is now a opinion at Icelandic Met Office that a small eruption did take place in Katla volcano during the days 8 and 9 July 2011. This eruption was however larger then the eruption in Fimmvörðuháls in Eyjafjallajökull volcano last year (2010). But this is based on tremor data from around Katla volcano during this summer. But this is what Einar Kjartansson geologist at Iceland Met Office says in the news at Rúv this evening. Even if this small eruption did take place in Katla volcano it does not seems to have eased the pressure inside Katla volcano, so a large eruption in Katla volcano is still a possibility in the close future. Note: GVP has updated Katla volcano eruption status to the year 2011!

This conclusion was reached by checking out the cauldron that formed during this event. But they show a sign that they had a sudden melt taking place. But that melt can only happen of lava got into contact with the ice and fast melted it. This is also the reason why there was a 5 meters flood in Múlakvísl glacier river that did destroy the bride over it. But it is also a fact that the harmonic tremor in Katla volcano during this period was the same as that did happen during the eruption in Eyjafjallajökull volcano. The only difference was that it it was stronger from Katla volcano then in Eyjafjallajökull volcano it seems (at least from what I can see from the data). Even if it lasted for a shorter time then in Eyjafjallajökull volcano.


The tremor on Slysaalda SIL station on 9 July 2011 at 00:36 UTC. Copyright of this picture belongs to Iceland Met Office.


Alftagrof SIL station on 9 July 2011 at 00:36 UTC. Copyright of this picture belongs to Iceland Met Office.


The area that was active and had a eruption on 8 and 9 July 2011. Copyright of this picture belongs to Iceland Met Office.

Even with this small eruption it is clear that Katla volcano is not done with its eruptions. Since the large one is not yet over. When that happens is a good question and nobody has a answer too at the moment.

Note: This is also what did happen in Hamarinn volcano the week after. But I also think that volcano did have a minor eruption in July 2011. As the signatures are the same from what I can gather. So that makes three eruptions in Iceland for the year 2011 if confirmed later on.

Icelandic News with this. Use Google translate with care on it. Since it does not understand.

Allt bendir til Kötlugoss (Rúv.is, Icelandic, Picture)
Segir Kötlu hafa gosið í sumar (DV.is, Icelandic, Picture)
Lítið eldgos í Kötlu í sumar (mbl.is, Icelandic)