Category: Magma

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Earthquake swarm in Katla volcano today (24.06.2012)

Earthquake swarm started in Katla volcano at 13:33 UTC. This earthquake swarm lasted until 14:26 UTC (24 June, 2012). Most of the earthquakes in this swarm where small. Less them magnitude ML1.0 in size. The largest earthquakes did have magnitude of ML1.3 and ML2.0. No harmonic tremor did take place during this earthquake swarm. However, harmonic tremor data from IMO suggests a lot of hydro-thermal activity under Mýrdalsjökull glacier. This might result in small glacier floods coming from Mýrdalsjökull glacier in hours to days time. There is also a good chance that new earthquake swarm starts in Katla volcano at any time. Since there has been pattern of repeated earthquakes swarms in Katla volcano for several weeks now.


Earthquake activity in Katla volcano today. The newest earthquake also appears on this image. Copyright of this image belongs to Iceland Meteorological Office.


The harmonic tremor level at Álftagrof SIL station. This is normal background movement. There are however clues that hydro-thermal activity might have increased under Mýrdalsjökull glacier following this earthquake swarms. Copyright of this image belongs to Iceland Meteorological Office.


Harmonic tremor at Slysaalda SIL station. This is normal background noise. Spikes are earthquakes in Katla volcano. In this image there are also minor clues about increased hydro-thermal activity in Katla volcano. Copyright of this image belongs to Iceland Meteorological Office.


The earthquake at 13:45 UTC on Skeiðflöt geophone. This trace is filtered at 1Hz. This image is released under Creative Common Licence. See CC Licence page for more details.


The earthquake at 13:45 UTC on Heklubyggð geophone. This is filtered at 1Hz. This image is released under Creative Common Licence. See CC Licence page for more details.

It is hard to know for sure what happens next in Katla volcano. But I am sure this activity is currently taking place is going to continue. This does however not say anything about possibility of an eruption in Katla volcano. That possibility remains unclear, as earthquake activity does not mean that an eruption is imminent. For the moment, there are just earthquake swarms taking place in Katla volcano. But that can change without warning. Until then less speculation on what is taking place in Katla volcano is best (in the news media anyway).

Blog post updated at 08:34 UTC on 25.06.2012.

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Earthquake swarm in Katla volcano, Kolbeinsey ridge, Hveravellir geothermal area

It has been a bit busy day earthquake wise in Iceland. But there has been more activity today then in past few weeks in Iceland. But it has been really quiet for a long time now in Iceland. But let’s start with the largest earthquake of the day.

Kolbeinsey Ridge

Today at 11:11 UTC there was an earthquake with the magnitude of ML3.65. This earthquake was not felt since it was more then 100 km away from nearest human population in Iceland. The earthquake took place on Kolbeinsey Ridge. It last erupted in the year 1755. No known eruption is known in this area since then. My geophone network did record this earthquake properly. The signal was strongest at my Hvammstangi geophone station. But it was also recorded on my Heklubyggð geophone station. On other geophone stations. The signal was too weak to be properly detected by my geophone.


The ML3.65 magnitude earthquake as it was recorded on my Hvammstangi geophone. This image is released under Creative Commons licence. Please see the CC Licence page for more details.


The ML3.65 magnitude earthquake as it was recorded on my Heklubyggð geophone. It is filtered at 1Hz. This image is released under Creative Commons licence. Please see the CC Licence page for more details.


The location of the earthquake. Copyright of this picture belongs to Iceland Meteorological Office.

Hveravellir geothermal area

There is an earthquake swarm ongoing (or it might be over. I have no good way to know that currently) at Hveravellir geothermal area. I only know there is an earthquake swarm there because of the tremor recording on Hveravellir geothermal area. But only two earthquakes have been large enough to appear on earthquake map on IMO web page.


The two earthquakes that did appear on IMO earthquake map. Copyright of this picture belongs to Iceland Meteorological Office.


However, Hveravellir SIL station did show that more was going on then did appear on the earthquake map. Most of this earthquakes are too small to appear automatic on the earthquake list. Some might even be too weak to be properly located by the SIL network. Copyright of this picture belongs to Iceland Meteorological Office.


Some of this activity did also appear on Skrokkalda SIL station I think. Copyright of this picture belongs to Iceland Meteorological Office.

Katla volcano

Katla volcano did have an new earthquake swarm during the night. This earthquake swarm had around 30 or so earthquakes. Most of them where located almost in the central caldrea. This type of swarm activity has now been ongoing since end of April, when it started rather sharply with an earthquake swarm. Since then it has had many earthquake swarm. But the current rate of earthquake swarm is around 1 to 3 earthquake swarm pr. Week. Normally they are in an new area inside the Katla volcano caldera.

My geophone station at Skeiðflöt records most of the earthquakes if the background noise is not too high during that time.


The earthquake activity in Katla volcano last night. Copyright of this picture belongs to Iceland Meteorological Office.

So far. This is just normal earthquake activity. It does not signal any chance of eruption activity so far. But this earthquake pattern is interesting. What it means is a different matter. So far, nobody knows for sure at this point in time. This activity seems to change hydrothermal activity inside Katla volcano caldera. This has also created minor glacier floods from Katla volcano caldera. But the flood have been seen on instruments that record water conditions in Múlakvíls glacier river. Glacier floods are marked by higher conductivity of the water, darker color and stronger sulfur smell (rotten egg smell). What happens next in Katla volcano is anyone guess. As Katla volcano has proven to be unpredictable volcano.

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New earthquake swarm in Katla volcano on 11. June 2012

Today from 04:00 to around 08:00 UTC this morning. There was an earthquake swarm in Katla volcano. This earthquake swarm was not large in the magnitude of the earthquakes. With the largest earthquakes being around ML2.0 in magnitude. There has been slight increase in conductivity in Múlakvísl river following this earthquake swarm. That suggests water is now leaking from hydro-thermal vents in Mýrdalsjökull glacier. So far no change in harmonic tremor has been seen. So for now, this are just earthquakes taking place inside Katla volcano caldera.


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

It is difficult to know what happens next in Katla volcano. As it is bit unclear what is exactly taking place in Katla volcano. With the lack of harmonic tremor following this earthquake swarms. This simply might just be normal summer earthquake swarms taking place. But Katla volcano is well known for that type of behavior during the summer in Iceland. With the most earthquake activity taking place in July and August.

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Earthquake swarm in Katla volcano yesterday (07.June 2012)

Yesterday there was an earthquake swarm in Katla volcano. Over 50 earthquakes have been recorded so far. But this earthquake swarm stopped yesterday at 16:22 UTC. Most of the earthquakes where shallow, with depth less then 1 km. Largest earthquake had the magnitude of ML2.5. No harmonic tremor was detected following this earthquake swarm. But that is unlike what did happen last year, when a similar earthquake swarm took place in Katla volcano.


Earthquake activity in Katla volcano yesterday (07. June. 2012). The main areas appear clearly on this map. The small dot SE on the caldera rim is an area that became active after last years minor eruption. What is taking place there is still an mystery. Copyright of this picture belongs to Iceland Meteorological Office.

This activity appears to be similar to what happened around 9th July, 2011. But no harmonic tremors are taking place in Katla volcano following this earthquake swarm.


Earthquake activity in Katla volcano on 9. July 2011. This good to compare the earthquake activity yesterday (image above this one). Copyright of this picture belongs to Iceland Meteorological Office.


The ML2.98 magnitude earthquake that happened in Katla volcano yesterday (07. June. 2012). This is the earthquake as it was recorded on Skeiðflöt geophone station. This image is released under Creative Commons License. See License page for more details.


Same earthquake as above. But filtered at 1Hz and this is how the earthquake appeared in Heklubyggð geophone station. This image is released under Creative Commons License. See License page for more details.

So far this is just an earthquake swarm. As there are no harmonic tremor signal taking place as the earthquake swarm is taking place. I do not know if there has been any glacier flood following this earthquake swarm. But if there was. It would mean that hydrothermal vents under Mýrdalsjökull glacier have been emptying out. It happens regularly in glacier such as Mýrdalsjökull glacier.

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Special report: New magma injection at depth in El Hierro volcano

While I have returned to just covering Iceland volcano and earthquake activity. It does not mean that I have stopped to watch the earthquake activity in El Hierro volcano at present time.

New earthquake activity with the depth of 15 to 28 km have been taking place in El Hierro volcano today (04.06.2012). Minor earthquake activity has also taken place on 29. May, 1. June, 3. June. But this where not many earthquakes. Nothing suggests that eruption has resumed in El Hierro volcano. However an new injection of magma into El Hierro volcano might have increased hydro-thermal activity in earlier eruption vents, or moved older magma that is already high up in the fissure that was eruption. That however does not mean that the eruption has resumed. But there is nothing in the data from El Hierro volcano to suggest that an eruption has resumed at this point.

For the moment, it is mostly quiet in El Hierro volcano. I fully expect that to continue for the time being. At least it is clear that more needs to happen in El Hierro volcano before an new eruption starts in El Hierro volcano. So for the moment, there is nothing to worry about in my opinion.

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Minor earthquake swarm in Katla volcano

Today (28.05.2012) at 11:22 UTC an small earthquake swarm did start in Katla volcano. This earthquake swarm did end at 12:28 UTC. This is small earthquake swarm, both in numbers of earthquakes and in the magnitude of the earthquakes in the swarm. With the largest earthquake having the magnitude of ML1.4. The depth of this earthquake swarm was around 0.1 km, but that gives the depth around 100 meters or so. Following this earthquake there has been some minor disturbance at Álftagróf SIL station. But because it only appears on one SIL station. This change might have its origin in something else. Like human traffic, local wind etc. For the moment I cannot rule that out.


The change in tremor at Álftagróf SIL station. This change in tremor might not be because of Katla volcano. But something else. Please keep that in mind. Copyright of this picture belongs to Iceland Meteorological Office.

If the tremor changes at Álftagróf SIL station where from Katla volcano. They where highly local and did not show up on other SIL stations for some unknown reason. That has happened before, but the SIL network was not as dense around Katla volcano back then.


Image of the active area in Katla volcano. Copyright of this picture belongs to Iceland Meteorological Office.

I find it most likely reason for this earthquake swarm where some changes in hydrothermal areas inside Katla volcano caldera. All hydrotheraml areas in Katla volcano are under high pressure due to the glacier that is on top of them. So changes might not happen without some earthquake activity as did happen few hours ago. This is also not in any way a sign that Katla volcano might be about to erupt. This is far too low earthquake activity for such event to be starting. There is an chance of small glacier flood following this earthquake swarm in next 8 to 24 hours. But it is far from certain that is going to happen.

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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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Earthquakes in Katla volcano. Earthquake swarm continues close to Herðubreið. Other earthquake activity

This morning there was a short earthquake swarm in Katla volcano caldera. This earthquake looks like a minor dike intrusion did take place this morning. Current series of events did start on 28. April 2012. With a small earthquake event and a small glacier flood that did follow it. Along with harmonic tremors coming from the glacier flood and possibly Katla volcano caldera (hydro-thermal activity boiling or something of that nature). I do not yet know if there was any glacier flood following the event this morning. But so far there is nothing that suggests a small glacier flood did take place following the earthquake swarm this morning.

The earthquake swarm this morning took place on an location that did erupt on 8 and 9th of July 2011. So it is clear the area that erupted last year is picking up activity again. But there was an drop in activity from end of November 2011 until end of April 2012.


Earthquake activity in Katla volcano this morning. Copyright of this picture belongs to Icelandic Meteorological Office.

This earthquake activity did appear well on my geophone at Skeiðflöt farm.


Earthquake activity in Katla volcano caldera this morning on my Skeiðflöt geophone. There is a lot of noise on this geophone. But earthquake activity can still be seen on this. The earthquakes are marked by red (some noise is also marked by red). This picture is released under Creative Commons Licence. See CC Licence page for more details.

It is clear that Katla volcano seems to be warming up to an eruption. But it is impossible to know when such eruption might happen, or how big it is going to be.

Herðubreið

Earthquake activity continues south-west of Herðubreið. But almost all of the earthquakes have been less then ML2.0 in magnitude. Earthquake activity has been slowing down all day. At the moment, it appears this earthquake swarm is close to being over.


The earthquake activity close to Herðubreið mountain. Copyright of this picture belongs to Icelandic Meteorological Office.

This area is well known for for earthquake activity. So this is not something that is new in this area.

Reykjanes Ridge

According to EMSC and USGS there have been several earthquakes with the magnitude of Mb4.5 to Mb4.8 on the Reykjanes Ridge. Earthquake activity is common on the Reykjanes Ridge. But because of the location and depth (around 2km) it is impossible to know if there any volcano eruption taking place at this location. It might well be, or not.

Kolbeinsey Island

Over the past weeks there has been some earthquake activity close to or in Kolbeinsey Island. The largest earthquakes have had the magnitude around ML3.0, with some underestimates due to distance from the SIL network. At this moment it is impossible to know if this earthquake activity is related to possible eruption activity. But it believed that an eruption (or dike intrusion) took place on Kolbeinsey Ridge in the year 1999. It started off with a large earthquake swarm.

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Katla volcano warming up for an eruption. Small glacier flood continues

This is going to be a short blog post. As I am going to be short of table and a cheer for few more days.

It seems that Katla volcano is warming up for a eruption. As I did mention in last blog post. But there is more to this. As the glacier flood that started on the 28. April 2012 continues according to a email that I got from an geologist working at Iceland Meteorological Office. But that suggests two things. That there is currently an ongoing melting of glacier taking place in Katla volcano, or there is a slow drainage taking place from some area in Mýrdalsjökull glacier. But given increased conductivity following this it is clear that this water has been in contact with magma. But that can be seen with the increased conductivity in the water.

There have not been many earthquakes following this events. But from the earthquakes that have happened. It seems that most likely source for current events is close to or the same area that erupted in July 2011. But at the moment this is just speculation based on limited data. It has not been confirmed so far.


The harmonic tremor that started on 28. April 2012. This is Lágu Hvolar SIL station. Copyright of this picture belongs to Iceland Meteorological Office. Used with written permission.

This plot shows clearly how the harmonic tremor starts and continues at same level for several days. I do not know if the harmonic tremor is ongoing. But I find it likely, if the small glacier flood is currently going on (that was my last information, but things might have changed during the day). But it is hard for me to know that for sure. But based on latest data from the water monitoring system around Katla volcano, the spike in this glacier flood is most likely over for now. But it impossible to know what happens next in Katla volcano. All that can be done is to wait and see what happens next.

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Small glacier flood from Mýrdalsjökull glacier on 28. April 2012 [Updated]

This has to be short. I do not have any table to cheer right now. I have already bought one (used and cheap). But I get it next week. I also do not yet have a ADSL connection so far. But this is what happens when one moves between countries.

On the 28. April 2012 there was a small glacier flood from Mýrdalsjökull glacier that on top of Katla volcano. This activity did start few days earlier according to Iceland Meteorological Office. But it did peak on the 28. April 2012. This was then followed by a small glacier flood in Múlakvísl river. The same river that had the glacer flood last summer, that did destroy a bridge in that same area.


The red line marks the harmonic tremor of Katla volcano. The blue line marks the conductivity in Múlakvísl glacier river. This is from Week 18 of the year 2012. Copyright of this picture belongs to Iceland Meteorological Office.

There was also a second event that took place in Katla volcano on 6 and 7. May 2012. But I do not know if there was any glacier flood in Múlakvísk glacier river following that event. Buit it is clear that Katla volcano is warming up again. This events are clearly something that I consider a warning on what is going on in Katla volcano. But it is a question if it continues or just stops, as so often does happen with volcanoes.

Update 1: According to a email answer that I got with a question of mine. This glacier flood is currently ongoing. It has not stopped so far. But this is a small glacier flood. But this is a interesting what is going on in Katla volcano at the moment.

Icelandic news about this.

Smáhlaup í Múlakvísl (mbl.is, Icelandic)

Blog post updated at 14:38 CEST on 11.05.2012.