Category: Magma

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Magnitude 3.1 earthquake in Katla volcano this morning

Today at 08:26 UTC this morning a magnitude 3.1 earthquake took place in Katla volcano. There was minor pre-earthquake activity before the magnitude 3.1 earthquake took place, the depth of this earthquake was around 100 meters (0.1 km). There was also some minor aftershock activity following this earthquake. No change in harmonic tremor took place following this earthquake. So there is a good chance this was just part of normal autumn activity in Katla volcano. This earthquake activity did appear clearly on my geophone network. It can be viewed here on my geophone network web page.


The earthquake as it did appear on my geophone station in Skeiðflöt. This image is released under Creative Commons licence. See CC licence page for more details.


The earthquake as it did appear on my geophone station in Heklubyggð. This image is released under Creative Commons licence. See CC licence page for more details.


The location of the earthquake in Katla volcano. Copyright of this image belongs to Icelandic Meteorological Office.

More earthquakes like this should be expected in Katla volcano. But it is impossible to know if there is going to be an eruption in Katla volcano any time soon. But so far everything is quiet in Katla volcano. Besides occasional earthquake swarm that is taking place in Katla volcano.

Icelandic news about this earthquake activity

Jarðskjálfti í Kötlu – 3,2 að stærð (Rúv.is)
3,2 stiga skjálfti í Kötlu (mbl.is)
Snarpur skjálfti í Kötlu (Vísir.is)

Blog post updated at 19:34 UTC on 03.10.2012
Blog post updated at 05:45 UTC on 04.10.2012

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Minor earthquake swarm in Katla volcano

Tonight around 22:30 UTC there was an minor earthquake swarm in Katla volcano. This earthquake swarm did last in about 20 minutes. After that the earthquake activity did drop back to normal background levels. This earthquake swarm is most likely part of normal autumn earthquake activity in Katla volcano. More earthquake swarms like this should be expected in Katla volcano during next few weeks.


Earthquake activity in Katla volcano this evening (28.09.2012). Copyright of this image belongs to Icelandic Meteorological Office.

What happens next is impossible to know. But I am not expecting anything special to happen in Katla volcano following this earthquake swarm. This earthquake swarm did appear clearly on my geophone at Skeiðflöt and Heklubyggð. The geophones can be viewed here.

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Earthquake activity drops in El Hierro volcano

Earthquake activity in El Hierro volcano has started to drop off again. During the last 24 hour period there have only been something around 28 earthquakes. But earthquake activity did peak with 182 earthquakes during 24 hour period on Sunday 16. September 2012.


The earthquake activity in El Hierro volcano at 19:22 UTC. As can be seen here. Everything is quiet for now.Copyright of this image belongs to IGN.

It is hard to say what happens next in El Hierro volcano. But magma is still getting injected into El Hierro volcano at depth. Eruption is still an possibility while inflation continues at the rate it is going. There is always the chance that deflation is going to start in El Hierro volcano. Chance of an eruption in El Hierro volcano remains high. But when it might start it impossible to say at this point.

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Constant earthquake activity in El Hierro voclano

On the 14. September 2012 an earthquake swarm started in El Hierro volcano, Canary Islands, Spain. The earthquake swarm is currently ongoing and there have been more then 300 earthquakes already. The earthquake activity is more or less constant at the moment. Since yesterday (16.09.2012) had around 182 earthquakes have taken place during the past 24 hour period (when this is written). The depth of this earthquakes is around 18 to 28 km. But this suggests an new magma intrusion into El Hierro volcano, or at least that magma is on the move inside El Hierro volcano from older sill inside it.


Start of the earthquake activity in El Hierro volcano. Copyright of this image belongs to IGN.


The earthquake activity on 15.09.2012. There is also an harmonic tremor pulse in this image. The first harmonic tremor pulse starts at 09:00 and lasts until 09:25 UTC. The second harmonic tremor pulse starts at 18:50 and lasts until 19:25 UTC. Copyright of this image belongs to IGN.


The earthquake activity yesterday (16.09.2012) until 21:14 UTC when this image was saved. No harmonic tremor pulses can be seen on this image. But earthquakes appear clearly on this image. Copyright of this image belongs to IGN.

This magma that is being injected into El Hierro volcano now is unlikely to erupted. But there is an pocket of magma located North of the El Hierro Island that might erupt. That magma pocket is only located about 10 km from the top of crust. In the start of the current that area was making earthquakes. But it soon did go silent. Why that I do not know.


The current area of activity in El Hierro volcano. As can be seen it is mostly located at great depth. But the pocket of magma that is located at 10 km depth north in El Hierro volcano might be reason to worry about. This image shows the activity over the past 4 days. Copyright of this image belongs to IGN.

The area that I worry about is marked by blue dots in the image above.


The current activity over the past 36 hours in El Hierro volcano. This image clearly shows where most of the activity has been taking place during this time period. Copyright of this image belongs to IGN.


Earthquake data for the past 1 year in El Hierro volcano. Copyright of this image belongs to IGN.

It is only when we get the earthquake data for past 1 year when things get really interesting. Based on this data. Magma is now already at the depth of around 10 km in El Hierro volcano. Why it has not erupted is hard to answer (the answer might come after an eruption takes place. But no sooner). There are even clues in this image that some of the magma might be as shallow as 5 km. But it is hard to see it for sure. This image also suggest that amount of magma in El Hierro volcano, in the forms of magma sill is a lot more then what did erupt last year in El Hierro volcano. The tube that is feeding this magma into El Hierro volcano appears to be located at 18.05 longitude. That tube is marked by earthquakes going down well below 28 km depth.

The current earthquake activity in El Hierro volcano is creating new magma sill inside the volcano. That is just storing magma for possible future eruptions. The activity so far has been bit stronger in terms of amount of earthquakes since last earthquake swarm in June and July 2012. But that earthquake swarm did top at around 172 earthquakes during 24 hour period. So the current earthquake swarm is larger in that regard. But so far no earthquake has been larger then magnitude 3.2. But that might change if any larger earthquake happens. As often is the case.

It is hard to say what happens next in El Hierro volcano. But I would guess that once eruption starts in El Hierro volcano it might last for months. Based on the amount of magma that seems to have build up inside the volcano during the past few months. That build-up phase however does not seems to be completed at the moment. How long it is going to last is impossible to say at current time. But this is something that is worth keeping an watch for. El Hierro volcano is going to erupt basalt if the eruption is on land. Older volcano cones are not going erupt again. At least that is my assessment of what I have seen with satellite pictures.

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Earthquake swarm on Reykjanes Ridge last night (16.09.2012)

Last night there was an earthquake swarm on Reykjanes Ridge. Possibly on one of the volcanoes that are in this area of Iceland. The earthquake swarm lasted for several hours. Strongest earthquakes in this swarm had the magnitude of 3.5. With the depth from 23 km and up to 0.3 km. Strongest earthquakes in this swarm where visible on my geophone network.


The earthquake swarm on the Reykjanes Ridge. Copyright of this image belongs to Icelandic Meteorological Office.

Last earthquake swarm in this area was on 8. February 2012. There was also earthquake activity deep on the Reykjanes Ridge. With two earthquakes that did get the magnitude 4.4 (EMSC) at 12:51 UTC. The second earthquake took place at 14:30 UTC and had the magnitude of 4.4 (EMSC). This earthquake activity is far enough from land that only the largest earthquakes are detected.

But there seems to be a lot of earthquake activity both south and north of Iceland (Jan Mayen earthquake activity). But this not connected activity as such. But it is known that activity on Reykjanes Ridge happens in jumps. It is an question if such time has come that an new activity episode is about to start on the Reykjanes Ridge. But last major episode in activity on the Reykjanes Ridge ended about 671 years ago. But there is one eruption documented off the coast in the year 1926 according to Global Volcanism Program. That activity did last for 4 days or so.

I am not sure what is going to happen next on the Reykjanes Ridge. But I am going to report it best to my ability. With the best information that I can get when the time comes.

Icelandic news about this earthquake activity

34 skjálftar frá miðnætti (mbl.is, Icelandic)

Blog post updated at 02:47 UTC on 17.09.2012

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Continued earthquake activity on Kolbeinsey Island ridge

In the past few days there has been considerable earthquake activity in Kolbeinsey Island ridge. Many of the earthquakes have been reaching the magnitude of at least 3.0. But some of it might be underestimation. As this earthquake activity is taking place far off Iceland coastline and far away from the SIL network. But that makes detection of earthquakes more difficult. Along with effects of weather and ocean waves that often prevent detection of smaller earthquakes in this area.


The location of the earthquake activity in Kolbeinsey Island ridge. Copyright of this image belongs to Icelandic Meteorological Office.

This is not the only activity in this area in the past few weeks. But the largest earthquake in this area was an magnitude 4.4 to 4.6 few weeks ago. So the activity in this area seems to be connected to something major. It is an question if this is due to volcano eruption currently taking place in this area now. But with depth of up to 4 km. It is impossible to know that for sure without actually going there on an ship. But given current weather. That is not going to happen any time soon. Maybe not for several years in fact.

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Deep earthquake in Eyjafjallajökull volcano

On 11.09.2012 at 10:24 UTC there was an deep earthquake in Eyjafjallajökull volcano. The magnitude of this earthquake was 0.8. It had the depth of 14.9 km. But that is among the deepest that happens in Eyjafjallajökull volcano. But before and during the eruption of Eyjafjallajökull volcano in the year 2010 the most depth of earthquake detected at that time was around 30 km.


The earthquake in Eyjafjallajökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

I do not expect this earthquake to mean anything. This is just single earthquake that now happen from time to time in Eyjafjallajökull volcano. But after the eruption in the year 2010 there has almost been no earthquake activity in Eyjafjallajökull volcano.

Volcano ash from Eyjafjallajökull volcano

Even if there are now two years since the eruption in Eyjafjallajökull volcano the local area continues to have problems with volcano ash from it. In certain wind direction the volcano ash is blown up and carried out to the sea. This wind direction is mostly when wind is blowing from north and does not carry any snow or rain with it. So today and maybe in next few days. The local people that live in the area around Eyjafjallajökull volcano to live in ash cloud from the eruption two years ago.

I did try to find an MODIS picture of this volcano ash storm. But I did not have any luck doing so.

Icelandic news about this wind blown ash

„Stödd í öskubakkanum“ (DV.is)

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Harmonic tremor pulse activity maybe in Hamarinn volcano

Today (02.09.2012) a harmonic tremor pulse did start in Hamarinn volcano (best guess) (Bárðarbunga volcano). This harmonic tremor pulses are intermittent and normally last for up to 20 to 30 min., at the time. What is creating them is hard to say. But this might just be hydro-thermal activity taking place in Hamarinn volcano. This might also be magma on the move inside Hamarinn volcano. But nothing is confirmed so far. I do not expect anything to be confirmed any time soon.

The harmonic tremor pluses appear on the end of the traces on this image. They are bit hard to spot for the untrained eye. But they appear as higher then background noise change in the tremor plot image.


The harmonic tremor pulse as it appears on the SIL station at Grímsfjall volcano. This is high resolution image from this IMO web page. Copyright of image belongs to Icelandic Meteorological Office.


The harmonic tremor pulse at Skrokkalda SIL station. Copyright of image belongs to Icelandic Meteorological Office.


The harmonic tremor pulse at jok SIL station. Copyright of image belongs to Icelandic Meteorological Office.


Harmonic tremor pulse at dyn SIL station. Copyright of image belongs to Icelandic Meteorological Office.

It is impossible to know what this means exactly. But so far there are no signs of eruption in the area. This activity is less then activity in July 2011 that was created by an minor eruption in Hamarinn volcano. Stronger harmonic tremor pluses appear on SIL station at longer distance. But for now (when active) most of the activity only appears on SIL stations closest to the Vatnajökull glacier. I am going to continue to monitor the current situation. I will update or make a new blog post about what is going on if anything happens.

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Magnitude 3.2 earthquake on the Reykjanes peninsula

Today (01.09.2012) at 16:33 UTC there was an earthquake with the magnitude of ML3.2. The depth was 7.6 km. Following this earthquake there was an swarm of smaller earthquakes following the first earthquake. None of those have been above magnitude 2.0. The earthquake took place in the Reykjanes volcano most likely. But it appears tectonic in nature. Rather then volcanic.


The magnitude ML3.2 earthquake on the Reykjanes peninsula. Copyright of this image belongs to Icelandic Meteorological Office.

It is hard to know for sure if this activity is going to continue. But since this earthquakes. Activity in this area has stopped. But it might resume at later time.

Icelandic news about this earthquake

Jarðskjálfti á Reykjanesskaga (Rúv.is)
3,2 stiga skjálfti við Grindavík (mbl.is)