Category: Volcano

Posted on

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.

Posted on

Possible glacier flood from Grímsfjall/Grímsvötn glacier lake (Unconfirmed)

There seems to be a glacier flood did start this morning in Grímsfjall glacier lake. Based on the tremor, the glacier flood is already subsiding or something of that nature. So far this glacier flood has not yet been confirmed by monitoring scientists. So I am unsure what exactly what is going on. But current activity seems to have started around 13. June 2012, when the tremor changed from normal background noise to higher frequency noise. This can be seen on the SIL station from Grímsfjall volcano.


Grímsfjall SIL station tremor reading. The spike marks what seems to be a glacier quake taking place. Copyright of this image belongs to Iceland Meteorological Office.

This harmonic tremor started early this morning. But it can be up to 12 to 24 hours before the glacier flood is visible in the rivers that flow from Grímsfjall volcano.


The second SIL station that tremor appears on from Grímsfjall volcano. Copyright of this image belongs to Iceland Meteorological Office.

Until there is official conformation what is exactly going on in Grímsfjall volcano. It is bit hard to know exactly what is going on there at the moment. But I hope that it is going to be cleared up in the next few hours or tomorrow. There are no signs that an eruption has started in Grímsfjall volcano at current time. It is impossible to know if that is going to change following this events that are taking place in Grímsfjall volcano.

Posted on

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.

Posted on

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.

Posted on

New pictures of Grímsfjall volcano crater

Rúv News has just published pictures of Grímsfjall volcano craters. This pictures where taken by Ómar Ragnarsson. The pictures show among them a Island that has formed inside the 1.5 km long and 800 meter wide crater that did erupt in May of last year.


The Grímsfjall volcano crater that erupted on 25. May 2011. Copyright of this picture belongs to Ómar Ragnarsson.

More pictures can be found on Rúv News web site. I recommend that people click on the images to get full size (or click and open in new tab).

Undraveröld Grímsvatna – Myndir (Rúv News, Icelandic, Pictures)

Posted on

Craters in Grímsfjall volcano clearly visible

The craters from last years eruption in Grímsfjall volcano are clearly visible on new pictures that Rúv did release in the evening news. There also seems to be some increase in hydro-thermal activity in Grímsfjall volcano. Based on the pictures and what was reported in the Rúv news this evening (02.06.2012).

When the eruption was at it largest last year, the crater was around 1.5 km in size. But once the power started to drop in the eruption, the single crater did turn into several small craters. The glacier is slowly closing this new crater. In few years time, there are not going to be many signs in this are that an large eruption took place there.

The new images can be viewed in this news on Rúv news web page.

Gígarnir í Grímsvötnum greinilegir (Icelandic, Video)

Posted on

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.