Category: Volcano

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Earthquake swarm on TFZ and in Þeistareykir volcano

This is going to be short blog post.

Earthquake east of Grímsey Island

Earthquake with the magnitude of ML3.5 (estimate) did take place at 19:48 UTC. This is normal tectonic activity for this area. But this area of Iceland has the most earthquake activity most of the year.


Earthquake activity in TFZ. Copyright of this picture belongs to Iceland Meteorological Office.

Þeistareykjabunga volcano

It was noticed by a reader of this blog that Þeistareykjabunga volcano was having few earthquakes. Þeistareykjabunga volcano last erupted in the year 900 BC (+- 100 years). This earthquake swarm was small. Mostly earthquakes with the magnitude of ML0.5 to ML1.0. The focal depth of this earthquake swarm was around 5 km. So this in all, is most likely an tectonic earthquake swarm. Rather then volcanic. Þeistareykjabunga volcano is an active volcano. But at current time I do not think anything has changed in that volcano at present time.


Þeistareykjabunga volcano is located north of Krafla volcano. Copyright of this picture belongs to Iceland Meteorological Office.

I do not expect anything more to happen in Þeistareykjarbunga volcano. But if there are changes, they won’t go unnoticed.

Thanks to Mafl for the tip on Þeistareykjabunga volcano.

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Quiet in Iceland earthquake wise

Currently it remains quiet in Iceland in terms of earthquakes and other geological activity. I am using that chance to have a bit of summer break. I am also going to move in August, so there is that. I am not moving back to Iceland. I am just moving inside Denmark. From Åbenrå to a small town named Padborg. But I think smaller towns work better for me then larger towns.

Because I am moving. I have to pay double rent in August. I hope that I do not have to pay double rent in September and October (that means more and new overdraft for me. Something I do think is an bad thing for me). This is going to leave me bit out of pocket. So all support is welcomed.

I am going to be on part-break until after I move to Padborg. But if anything major happens. I am going to write about it soon as possible.

Katla volcano

Katla volcano continues to have small earthquake swarm. What that means is still unclear. Largest earthquake in few days was earlier this week. That earthquake had the magnitude of 2.6 and had the depth of 0.3 km. Several smaller earthquakes did take place following this earthquake swarm. Since then Katla volcano has remained quiet. Small glacier floods are still a high risk from Mýrdalsjökull glacier.

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Small glacier flood from Mýrdalsjökull glacier (Katla volcano)

According to Rúv News this evening. A small glacier flood started flowing from Mýrdalsjökull glacier (Katla volcano) few days ago. According to local farmer in the area. Glacier floods like this are common and several have taken place during this summer, none of them have created damage. The current glacier flood is from a glacier river called Leirá river. This glacier flood is from an cauldron somewhere close to middle of Mýrdalsjökull glacier. There is small risk of damage to local roads and fiber optics cable in the area. Some glacier breakage has been reported in the glacier where the floods comes from.

I am going to update this blog post if anything major happens with this glacier flood.

Update 1: It now appears that this glacier flood is now appearing on Rjúpnafell SIL station. So far just on this only SIL station. But that might change at any time if this glacier flood grows in size.


The tremor from the glacier flood can be see at the end of this harmonic trace. The spike is an earthquake in Katla volcano. Copyright of this image belongs to Iceland Meteorological Office.

Icelandic news about this.

Lítið hlaup í Leirá (Rúv.is, Icelandic)

Blog post updated at 00:07 UTC on 14.07.2012.

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Minor earthquake swarm in Katla volcano

This Sunday is not quiet when it comes to earthquake activity in Iceland. Earlier today a small earthquake swarm started in Katla volcano. The largest earthquake in this swarm had the magnitude 2.3 according to the automatic SIL system. The largest earthquake did appear clearly on Skeiðflöt and Heklubyggð geophone stations. But Skeiðflöt geophone station is closest to the area where this earthquake swarm was taking place.


Earthquake swarm in Katla volcano. Copyright of this picture belongs to Iceland Meteorological Office.


The earthquake trace on Skeiðflöt geophone station. This is filtered at 1Hz. I have not located this earthquake trace (no P and S wave markers). This image is released under Creative Commons Licence. Please see CC Licence page for more details.


The earthquake trace from Heklubyggð geophone station. This is filtered at 1Hz. I have not located this earthquake trace (no P and S wave markers). This image is released under Creative Commons Licence. Please see CC Licence page for more details.

It is impossible to know what happens next in Katla volcano. But it is monitored heavily, so if anything happens. It is going to show up almost in real time on the internet.

GPS monitoring of Ice cauldron on Mýrdalsjökull glacier

In the news on Rúv yesterday (07.07.2012) they did tell about real time GPS monitoring of ice cauldron in Mýrdalsjökull glacier. But it is hoped that with this real time GPS monitoring they can give out warning sooner when a ice cauldron empties it self of the water it holds.

The news about this can be found here on Rúv News in Icelandic.

GPS-tæki komið í sigketilinn (Rúv.is, Icelandic, video)

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Earthquake activity in Katla volcano and on SISZ

It has been quiet for the past weeks in Iceland. I do not know if that is changing. But this is the short update of what has been taking place in Iceland earthquake wise during this quiet period.

Katla volcano

Since Katla volcano earthquake spike in late April to middle of June. Sine then it has been rather quiet in June and what has passed of July. Today and yesterday there has been some earthquake activity in Katla volcano. But nothing like was seen in April to June.


Earthquake activity in Katla volcano during past few days. Copyright of this picture belongs to Iceland Meteorological Office.

South Icelandic Seismic Zone (SISZ)

Intresting earthquake activity has been taking place in South Icelandic Seismic Zone for few days now. Currently the activity is on the northern end of the fault that broke in the year 2008. This is most likely just an earthquake swarm in the fault area that is continuing to adjust after the Mw6.3 earthquake in the year 2008.


Earthquake activity on SISZ during the past few days and hours. Copyright of this picture belongs to Iceland Meteorological Office.

As for SISZ. This is just an earthquake activity. There is no volcano activity in this area of Iceland. But SISZ is a fault zone that moves N-S (W-E compared to Reykjavík). So with every major earthquake on SISZ, it is slowly moving south as the new rift zone (Iceland East rift zone) moves south at the same time. This is a slow progress. Takes millions of years and has been ongoing for million of years already.

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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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Minor earthquake swarms in Iceland

It has been quiet in Iceland during the past few weeks. Besides activity in Katla volcano and Kolbeinsey ridge. Nothing of interest has been going on in Iceland. Here is however the overview of activity in Iceland during the past few hours.

Kolbeinsey Ridge

Some minor earthquake activity has been taking place in Kolbeinsey Ridge during the past few hours. This earthquake swarm is small in nature, with largest earthquakes reaching the magnitude 2.4. Otherwise it remains quiet in this area.


Earthquake activity in Kolbeinsey Ridge. Just north of Grímsey Island. Copyright of this image belongs to Iceland Meteorological Office.

Kolbeinsey ridge has seen some activity during past few weeks. But it might just be normal tectonic earthquakes taking place. So far nothing suggest any volcanism nature of this earthquake activity.

Krýsuvík volcano

During the past few hours. Krýsuvík volcano did see some earthquake activity. This activity is most likely to be tectonic in nature. As Reykjanes peninsula has frequent earthquake swarm that are tectonic in nature.


Earthquake swarm on Reykjanes. It is located within Krýsuvík volcano. This was small earthquake swarm. Copyright of this image belongs to Iceland Meteorological Office.

It remains rather quiet on Reykjanes besides this minor earthquake swarm today.

Katla volcano

After rather interesting activity during the past few weeks. It seems that Katla volcano is slowing down in earthquake activity. For now at least. But it is impossible to know for sure if current quiet sense is going to continue in Katla volcano.


Earthquake activity in Katla volcano during past few days. The activity is mostly concentrated into Katla volcano caldera. Copyright of this image belongs to Iceland Meteorological Office.

Besides this top of the activity. All is quiet in Iceland. Both in volcanoes and earthquakes. That might however change at any time without warning. It happens often in Iceland. I also want to remind people of my geophone web page. Where earthquakes can sometimes be seen soon after they have taken place.

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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/)