Category: GPS Monitoring

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Continuous earthquake activity in El Hierro volcano

There have not been great changes in El Hierro volcano. Currently no eruption has taken place. There are also no signs of magma movement on tremor plots on seismometers stations that are located on El Hierro Island. The dike intrusion in El Hierro volcano is continues, but at slower rate then before. But that it is continuing means there is continued risk of an eruption where the earthquakes are currently taking place. Currently the rate of earthquake is around 3 to 8 earthquakes during the hour. Most of the earthquakes are around ML1.5 to 3.4 in magnitude. Please note that I am missing all earthquakes with the magnitude of ML0.0 and up to ML1.5. So there might well be a lot more earthquakes taking place in El Hierro volcano then I am seeing on IGN web page.


Current tremor plot of El Hierro volcano. The spikes are earthquakes in most cases. Copyright of this picture belongs to IGN.


Last 36 hours of earthquakes in El Hierro volcano. It shows clearly where magma has pushed it self into the crust. Creating inflation and earthquakes. The spikes are earthquakes in most cases. Copyright of this picture belongs to IGN.


Past 7 months of activity in El Hierro volcano. This map shows well how magma has slowly been injecting it self into El Hierro volcano during the past few months. Some of the earthquakes there are also just tectonic earthquakes, due to stress changes that injection of magma creates in the crust. The spikes are earthquakes in most cases. Copyright of this picture belongs to IGN.

According to official reports. The inflation of El Hierro volcano is around 10 cm according to official reports, or around that. I am having hard time finding the official news reports on the inflation in El Hierro volcano at current time. For the moment, the current situation is stable for the moment. But when that might change is impossible to know for sure. But there is magma inside El Hierro volcano, so there is an increased risk of some of that magma finding it’s way to the surface and erupting. But that might be out in the ocean as last time, or on land. It is impossible to know that for sure until an eruption starts. For the moment, nothing can be done the to watch and monitor the current situation in El Hierro volcano.

Other

It seems that Icelandic volcanoes and fault zones are on some type of summer vacation for the moment. So I am covering other things while the quiet period in Iceland is currently ongoing.

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Short update on activity in El Hierro volcano, Canary Islands / Corto sobre la actividad de actualización en el volcán de El Hierro, Islas Canarias

This is just a short update on El Hierro volcano activity. I plan on making a longer blog post tomorrow when I am not so tired.

Current earthquake activity in El Hierro volcano is continues. The rate of earthquakes taking place in El Hierro volcano is about 10 earthquakes pr 1 hour. With high up to 20 earthquakes pr hour, and down to 2 earthquakes pr 1 hour. The rate of earthquakes with the magnitude larger then ML3.0 is about the same. They happen every few hours at random intervals. For the past few days a cluster of large earthquakes takes place every 10 to 12 hours. This pattern is not something to trust in, as it is going to change without warning. But it is controlled by inflow of magma at depth under El Hierro volcano. Most earthquakes take place at around 20 km depth, as that is where magma is being injected into El Hierro volcano. That however does not rule out the possibility of magma having reached higher up in the crust. Some of the earthquake taking place in El Hierro volcano are crustal stress earthquakes. As magma and inflation of El Hierro volcano is changing the stress in the crust close to it. The

Based on the data from last years events, the magma now is up to 5 km depth in the crust. That magma is for the moment not moving. It is just staying where it and cooling. That might change without warning if something changes inside El Hierro volcano. It is impossible to predict such event with any manner of accuracy. This magma is most likely going to stay where it is and cool off for the next few centuries (this is a different magma sill that is not creating so much earthquakes at the moment). The current magma injection is going to start an eruption in my opinion. It is just question of when and where. It is not a question of “if” in my opinion (non-professional opinion). Update: There are two or three magma sill in El Hierro volcano at present time. Not all of them are going to erupt. Current magma sill that is forming now is however going to erupt in my opinion. That sill formation has been creating earthquakes and inflation during the past two weeks. I know this sounds to be contradicting it self. But the situation in El Hierro volcano is a lot more complex then it seems.

I believe this location to the most likely place for an eruption. More or less. But there is also a risk of magma going somewhere unexpected. As is the risk with all volcanoes that erupt in the same manner as El Hierro volcano.


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Inflation has also been sharp following this earthquakes activity. With some areas reporting up to 120mm inflation during short period of time. This is common for volcanoes like El Hierro volcano. Some of this inflation areas might erupt in a fissure vent eruption. When and where are in this case impossible to predict until an eruption actually starts. This types of eruptions are normally not dangerous unless they are close to human habitat. This fissure vents might however be large in length, from several meters in length and up to several km long.

It is hard to know what happens next when it comes to volcano, any volcano that is. What happens in a volcano is poorly understood by everyone. So what happens next in El Hierro volcano is anyone guess. But I find it to be good advice for people living on the Island of El Hierro to stay alert for sudden change in El Hierro volcano behavior.

Spanish / Español (via Google Translate)

Esto es sólo una breve actualización sobre la actividad del volcán de El Hierro. Mi plan es hacer un mañana después de blog cuando ya no estoy tan cansado.

La actividad sísmica actual en El Hierro volcán continúa. La tasa de los terremotos que tienen lugar en El Hierro volcán es de unos 10 terremotos pr 1 hora. Con alta hasta 20 horas pr terremotos y terremotos de hasta 2 pr 1 hora. La tasa de terremotos con la magnitud más grande que ML3.0 es aproximadamente la misma. Se producen cada pocas horas a intervalos aleatorios. Para los últimos días un grupo de grandes terremotos se lleva a cabo cada 10 a 12 horas. Este patrón no es algo que confiar, ya que va a cambiar sin previo aviso. Sin embargo, está controlado por flujo de magma en las profundidades del volcán en El Hierro. La mayoría de los terremotos tienen lugar en torno a 20 km de profundidad, ya que es donde el magma se está inyectando en el volcán El Hierro. Que sin embargo no descarta la posibilidad de que el magma de haber alcanzado más arriba en la corteza. Algunos de los terremotos que tienen lugar en El Hierro son los sismos del volcán corteza de estrés. Cuando el magma y la inflación del volcán El Hierro está cambiando la tensión en la corteza de cerca a él. La

Con base en los datos de eventos de los años últimos, el magma es hasta una profundidad de 5 km en la corteza. Ese magma es por no pasar el momento. Se acaba de estar donde y refrigeración. Eso podría cambiar sin previo aviso si algo cambia en el interior del volcán de El Hierro. Es imposible predecir tal caso con cualquier forma de precisión. Este magma es más probable que va a quedarse donde está y refrescarse durante los próximos siglos (esto es un umbral de magma diferente que no es la creación de terremotos, por lo tanto en este momento). La inyección de magma en curso va a comenzar una erupción en mi opinión. Es sólo cuestión de cuándo y dónde. No es una cuestión de “si” en mi opinión (no profesionales opinión) . Actualización: Hay dos o tres alféizar de magma en el volcán de El Hierro en la actualidad. No todos ellos van a entrar en erupción. Alféizar de magma actual que se está formando ahora es, sin embargo va a estallar en mi opinión. Que la formación de solera ha sido la creación de terremotos y de la inflación durante las últimas dos semanas. Sé que esto suena a contradicción en si mismo. Pero la situación en El Hierro volcán es mucho más compleja de lo que parece. Link: Lámina (geología) (Wiki)

Creo que esta ubicación para el lugar más probable para una erupción. Más o menos. Pero también existe un riesgo de magma ir a un lugar inesperado. Como es el riesgo con todos los volcanes que hacen erupción de manera semejante como El volcán Hierro.


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La inflación también ha sido fuerte después de esta actividad los terremotos. Con algunas zonas informar a la inflación 120 mm durante el período de tiempo corto. Esto es común para los volcanes como el volcán El Hierro. Algunas de estas áreas la inflación podría entrar en erupción en un fisura de ventilación erupción. ¿Cuándo y dónde están en este caso imposible predecir una erupción hasta que realmente empieza. Este tipo de erupciones normalmente no son peligrosos a menos que se acercan al hábitat humano. Estos respiraderos de fisuras sin embargo, podría ser de gran longitud, de varios metros de longitud y de hasta varios kilómetros de largo.

Es difícil saber lo que sucede a continuación en lo que respecta al volcán, un volcán que es. Lo que ocurre en un volcán es poco comprendido por todos. Entonces, ¿qué ocurre a continuación en el volcán El Hierro es que nadie adivine. Pero me parece que sea un buen consejo para las personas que viven en la isla de El Hierro para mantenerse alerta para el cambio repentino en el comportamiento del volcán de El Hierro.

Blog post updated at 01:17 UTC on 04.07.2012. Explanation added to the blog post.

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Update on El Hierro volcano activity

This is a short update on the activity in El Hierro volcano.

In the last 24 hours there have been no major changes in the activity of El Hierro volcano. No eruption has started yet. But earthquake activity continues with the same rate as in past few days. Magnitude of the earthquakes that are currently taking place is around ML1.5 to ML3.5, with the focal depth of around 20 km. But deepest earthquakes have the depth of around 28 km. While the shallowest earthquakes have the depth around 15 to 12 km. No harmonic tremor is currently taking place in El Hierro volcano. According to GPS data from El Hierro volcano. There is inflation taking place at the current moment. That means magma is injecting it self into the volcano at the depth of 20 km. There is already older magma from last year magma injection. Some of that magma erupted last year, but not nearly all of it. I do not know what happens if the new magma gets into contact with older magma that is in El Hierro volcano. There is also possibility that older magma from eruptions that took place thousands years ago is still in El Hierro volcano. That magma might be andesitic to rhyolitic in nature. If that is the case is impossible to know for sure. But this is always an risk with any volcano, regardless where they are located in the world.


Earthquake activity in El Hierro volcano during last four days. Copyright of this image belongs to IGN.


Earthquake activity during one week in El Hierro volcano. This map clearly shows the extent of the magma during this past week. Copyright of this image belongs to IGN.


Earthquake activity since 1. January 2012 in El Hierro volcano. Copyright of this image belongs to IGN.


Total amount of earthquakes in El Hierro volcano since activity started last year. Copyright of this image belongs to IGN.


Current earthquake activity in El Hierro volcano. No harmonic tremor is currently being detected in El Hierro volcano. Copyright of this image belongs to IGN.

It is difficult to day what happens next in El Hierro volcano. But I do believe that current earthquake activity is going to continue for the next few days to weeks. That activity depends on how much magma flows into El Hierro volcano. That flow might not be constant all the time. So there is going to be period of time with low activity during current events. When this is written, total of around 130 earthquakes have taken place in El Hierro volcano today (29. June 2012) so far.

Known eruptions in El Hierro volcano

Year 4790 BC (Radiocarbon)
Year 950 BC (+- 150 years)
Year 550 BC (+- 75 years)
Year 1677 (Uncertain eruption. Not confirmed.)
Year 1692 (Uncertain eruption. Not confirmed.)
Year 1793 May to 1793 June. Erupted on NW rift, GVP says that the eruption may have taken place at Volcán de Lomo Negro (?). But that is not confirmed or established at current time.
Year 2011 September to December, off the coast. Not on GVP web page.

Source: GVP web page, Hierro

Blog post updated at 20:16 UTC on 29.06.2012.

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Analyze on events in El Hierro volcano

This is a short analyze of what is happening in El Hierro volcano. What is taking place in El Hierro volcano has an simple explanation. What is taking place in El Hierro volcano is an dike intrusion. This creates earthquakes as new magma is injected into the crust. This is also creating inflation on the surface. It has been reported so far the inflation is 20mm up, 20mm east, 20mm north. This can clearly be seen on GPS data that was released today.


The inflation according to IGN. This is recent GPS data. Copyright of this image belongs to ING/AVCAN

The dike intrusion into El Hierro volcano is creating sill in it. While new magma is being injected into the volcano. It is going to mean earthquake activity and a lot of it. Currently there are three older sill that have formed in El Hierro volcano. This sill clearly appear on images that show the earthquake pattern over the past one year in El Hierro volcano.


Earthquake activity marks the sill and older magma injection areas in El Hierro volcano. Copyright of this image belongs to ING/AVCAN


Earthquake activity in El Hierro volcano as it is today. This is accumulated earthquake activity sine current earthquake swarm started. Copyright of this image belongs to ING/AVCAN

What happens if the new injection gets into contact with the old inection is anyone guess. But new magma, if it gets in contact with an older magma might mobilize it. It might not mean an eruption. But earthquake activity might get really intense for a while. A lot more intense then it already is today. With earthquake well above magnitude ML3.0 and up to ML5.0 (depending on the stress of the crust in the area).


Earthquake activity in El Hierro volcano today. So far no harmonic tremors have been detected. But that might change without warning if the magma finds a path to the surface. Copyright of this image belongs to ING/AVCAN

When I write this I see that El Hierro volcano has had it first ML4.0 earthquake as I did fear yesterday might happen. But I made a comment on that on AVCAN Facebook page yesterday (Somewhere, I have no idea where it is located).

References:

Dike (geology) (Wiki)
Sill (geology)
Intrusion triggering of the 2010 Eyjafjallajökull explosive eruption (http://geoscience.wisc.edu/)

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Krísuvík volcano inflates and deflates regularly

It seems that Krísuvík volcano is inflating and deflating on regular basic. I do not know how regular this change is. But it has been noticed by Icelandic scientists how are bit puzzled by this behavior. Last inflation episode did last until end of the year 2011. Since then deflation did start again and is currently ongoing. It is uncertain if what this means. At the moment it is too early to know for sure if this means if that Krísuvík volcano is getting ready for an eruption. But if there was an eruption in Krísuvík volcano, it would be Hawaiian eruption so no volcano ash. Volcano ash eruption would only take place if an eruption started in Kleifarvatn lake. But the effects of that would be limited to local area (Reykjavík and other nearby towns). It would not create any global problems, as many would want to believe.

Inflation and deflation period have been the years 2009, from January to September. In May 2010 inflation did start again, that inflation period lasted until end of the year 2011. Since then deflation has been taking place. Today there is continues GPS monitoring in Krísuvík volcano. But it is unknown if this type of behavior has taken place before in Krísuvík volcano. But for now Krísuvík volcano is being monitored both with GPS and the SIL network. What happens next anyone guess.

Icelandic news about this.

Land rís og sígur í Krýsuvík (Rúv.is)

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Grímsfjall volcano prepares for new eruption

It is clear that Grímsfjall volcano is an restless volcano. In the year 2011 it had the largest eruption for at least 140 years. But even so that does not stop the volcano from preparing new eruption sometimes soon. But I am now expecting an new eruption from Grímsfjall volcano in the next 12 to 48 months or so at the earliest. The preparing for eruption clues have already started to show. But that is an slow increase in earthquakes in Grímsfjall volcano. Something that has always been a clear indicator of that an eruption might not be far off, even if nobody knows when and how big next eruption is going to be. It has been documented that Grímsfjall volcano does sometimes have an eruption every once or two year when the activity is at highest. But since the year 1983 the eruptions in Grímsfjall volcano have been getting more frequent and larger, the largest one so far being last year.


The latest earthquake in Grímsfjall volcano. It has not been reviewed so it’s location might change. Copyright of this picture belongs to Iceland Meteorological Office.


GPS data from the past 6 months (I think). As can be seen not a lot of magma has been going into Grímsfjall volcano system since the large eruption that started 21.05.2011. So far the inflation has only been around 100 mm to date, but even so that is more then whole inflation of Eyjafjallajökull volcano in the year 2010. But that was only around 60 mm for comparison. Copyright of this picture belongs to Iceland Meteorological Office.

It is unclear what happens next in Grímsfjall volcano. But for us how watch volcanoes. This is going to mean a lot of waiting time until next eruption in Grímsfjall volcano.

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Harmonic tremor pulse in Grímsfjall volcano

There have only been seven months since (May 2011) the last eruption in Grímsfjall volcano. But it seems that Grímsfjall volcano is getting ready for its next eruption. Even if the last eruption was the largest one for at least 140 years in Grímsfjall volcano. So far earthquake activity remains low in Grímfjall volcano. But I am not sure if that means anything for the moment. But there has been in earlier lead up to a eruption a build up of earthquake activity in Grímsfjall volcano.

Today at least two harmonic tremors spikes have been detected by IMO. But this type of harmonic tremor pulse have been detected before in Grímsfjall volcano. Older blog posts on that subject can be found here and here. But this time around it seems that the harmonic tremor is stronger then before. Currently it remains uncertain of there is a glacier flood starting from Grímsvötn lake, as was the case last time this type of harmonic tremor pulse was detected in Grímsfjall volcano.


Harmonic tremor in Grímsfjall volcano at 00:21 UTC on 5 December, 2011. Copyright to this picture belongs to Iceland Met Office.


The harmonic tremor in Grímsfjall volcano at 01:39 UTC on 5 December, 2011. Copyright to this picture belongs to Iceland Met Office.

There is a clear change in the harmonic tremor, as can be seen here. But why and what this actually means for Grímsfjall volcano I am not sure. But I am rather sure that this means a new eruption might only be several months away. But it is hard to know that for sure. But I am just base my estimate on earlier experience with Grímsfjall volcano. But it might not mean anything after last eruption.


The GPS data from top of Grímsfjall volcano. The data is missing for the last few days. Must be because of snow and ice. But given the last data set, the change so far it not that great since the eruption last spring. Copyright to this picture belongs to Iceland Met Office.

What happens next in Grímsfjall volcano is a big question. But it seems that Grímsfjall volcano is going to go for a new eruption. When that might happen I have no idea.

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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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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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Short update on El Hierro volcano eruption

This is a short update on El Hierro volcano eruption. As the situation is changing fast this past few hours.

It seems that the eruption in El Hierro volcano is gaining strength and power. The harmonic tremor on the seismomter that is on the El Hierro Island it self has started to get saturated again. It also have been unconfirmed reports of the south fissure growing in size. But so far nothing has happened in the north part of El Hierro volcano. Even if there have been many earthquakes in that area. But this area fell suspicious silent this morning. So something might be up in that area. Update 1: A string of earthquakes happened around 12:00 UTC in this area. Suggesting that something is still up there.


The harmonic tremor at 13:52 UTC. Notice how the tremor has started to saturate the seismometer. Copyright of this picture belongs to Instituto Geográfico Nacional.

What happens next is anyone guess. But people need to be aware that fissure eruptions are sometimes long in terms of the length of the fissure. But that phase normally does not last long, as soon the eruption is going to isolate it self into few craters on the fissure. I also recommend that people read Erik Klemetti blog post about El Hierro from yesterday. If you haven’t already done so.