Category: Volcano

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Magma movements under Hekla volcano have been confirmed

According to the news on Rúv the GPS movements that many have been seeing around Hekla volcano in the past few days are real. At the moment the civil disaster authorities have been notified and also local emergency authorities. Nobody seems to know what is going on with this magma moments for the moment. But they can be tracked with the GPS network to some extent. What is more interesting is that this does not seems to have started until few days ago. But first signals of this happening did take place in April and May, but at lot smaller scale. What is interesting is that fact that no earthquakes appear during this magma movements, there is also no harmonic tremor when the magma is moving around in the crust close to Hekla volcano. But if there is any earthquakes, noise or whatever coming from Hekla volcano it is going to appear on my geophone that is located about 16 km away from peak of Hekla volcano. The distance is even less from the actual edge of the Hekla volcano system it self.

Normally, there are no changes in the GPS network before an eruption in Hekla volcano. So this is highly unusual event in Hekla volcano since instrumental monitoring started few decades ago.

It is an question if this means an fissure style of eruption is going to take place in Hekla volcano. But that does sometimes happen, as with any volcano in Iceland. For the moment however the only thing that can be done is wait and speculate (within reason).

No eruption has started in Hekla volcano. But it can be assured that it might start without any warning and I might not be around the computer when that start, since I am working during the day and feeling tiered during the evening. But I am getting slightly better on that front, thankfully.

I am going to post more on this when I do know more, or if anything happens in Hekla volcano related to this.

Icelandic News about this.

Hræringar í Heklu (Rúv.is, Icelandic)

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New harmonic tremor spike in Katla volcano

Today around 16:00 UTC there was an new harmonic tremor in Katla volcano. This harmonic tremor has two sources. Hyrdothermal activity under the glacier, or magma moving deep inside Katla volcano (without creating many earthquakes in Katla volcano). It is unclear what is the case at the moment.

This spikes are so far not related to glacier floods from Katla volcano. But that sometimes also happen without an eruption being involved.


The harmonic spike can be seen here. Close the end of the chart. It is different then the background noise as it is more powerful then the background noise. Copyright of this picture belongs to Icelandic Met Office.

It is impossible to know what happens next. But it is also important to be aware of the fact that earthquake season is starting in Katla volcano. But that is normally from end of June to beginning of October (or when it starts to snow again in Iceland). So more earthquakes are going to be seen this summer also because of more SIL seismometers around Katla volcano.

So there is no reason to panic about Katla volcano at current time. But it is worth to keep watch on it anyway.

Notice: Updates might be an little few due the fact that I am now working all day during the week and I am tired in the end of the day with no energy to write new blog posts. But I am going to do my best anyway.

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Earthquake swarm in Presthnjúkar volcano. Update on Katla volcano

Presthnjúkar volcano: Few days ago an earthquake swarm did start in Presthnjúkar volcano. This earthquake swarm is entirely tectonic in nature. There is nothing that suggests that this earthquake swarm is connected to magma movements inside Presthnjúkar volcano system. So far this earthquake swarm has been slow and small. But the largest earthquakes have gone up to ML3.3 in size according to Icelandic Met Office.


The location of current earthquake swarm in Presthnjúkar volcano. Copyright of this picture belongs to Icelandic Met Office.

Katla volcano: Over the last 18 hours it has been quiet in Katla volcano. As no more earthquakes have been detected from it. I would not be surprised if there are more earthquakes swarms in Katla volcano in the next few weeks and months. It is an well known fact that Katla volcano is heading to an eruption. But nobody knows when that is going to happen.


Location of the earthquakes in Katla volcano yesterday. Copyright of this picture belongs to Icelandic Met Office.

Besides this two highlights of earthquake activity in Iceland. It has been rather quiet in the past few weeks. With just from ~100 to ~300 earthquakes during the week.

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Earthquake swarm in Katla volcano

Around 17:10 UTC an earthquake swarm did start in Katla volcano. This earthquake swarm is focused inside the Katla caldera at small point. The one earthquake that I have so far been able to record was an long period earthquake, but that suggests that this earthquake was created by magma movement. At current time I am not sure from where this earthquake did originate from. But from Goðabunga area in Katla volcano this types of earthquakes are common and no surprise at all.

At current time I do not know what this means for Katla volcano. But so far no increase in harmonic tremor has been detected on the seismometers around Katla volcano. But that might not start at current time, as harmonic tremor is only going to increase when magma starts to move inside the Katla volcano, like did happen in Grímsfjall volcano few weeks ago.

The location of this earthquake swarm strongly suggests that what is going on in Katla volcano is an dike intrusion in the Katla caldera. If that is powerful enough to start an eruption is an question remained unanswered at current time.


Area of activity is marked by the earthquakes. Looks like an dike intrusion into Katla caldera. Copyright of this picture belongs to Icelandic Met Office.

I am going to update or post new blog posts as this continues to develop. I do not think that this events are over. But it is hard to know for sure, since volcanoes are impossible to predict.

Post post updated at 18:39 UTC.

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General update of earthquake activity in Iceland and other things

Here is finally an new blog post from me. This week has been busy. As I did move to Hvammstangi again for this summer. But I did move to Iceland on the 5. June 2011. But just for the next 1 to 3 years, depending on how things goes for me. My work is hard, so I might not often have energy to write new blog post during the week. But I am going to do my best.

Now, the earthquake information on what has been going on in Iceland for the past two weeks or so.

Katla volcano: Even after the harmonic tremor pulse last week. Nothing special has been going on in Katla volcano. But it did come to my attentions that Icelandic Met Office did notice that in Week 23 there have been explosions (mine for road work in the area). So when an “earthquake” appears in that area. It means that an mine explosion have taken place in that area. I do not know when they are going to stop mining operations in this area.

Presthnjúkar: There continues some earthquake activity in the Presthnjúkar area. This earthquake activity appears to be tectonic and nothing else. The latest earthquake swarm taking place there appear to be starting tonight. It is hard to be sure how it is going to develop over the past few hours.

Other: There is currently not a lot other thing going on in Iceland.

I hope to make an better post tomorrow. When I am well rested and focused.

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Harmonic tremor pulse in Katla volcano

There appears to be an harmonic tremor pulse going on in Katla volcano. While I currently do not think that this is going to start an eruption. It is worth watching this harmonic tremor pulse in Katla. But in the year 1999 this type of activity did result in minor eruption in Katla volcano on the 17. July that year (it is believed).


Harmonic tremor pulse can be seen on the SIL station Lágu Hvolar. Copyright of this picture belongs to Icelandic Met Office.


Harmonic tremor pulse can be seen on this SIL station Álftagröf. But it is hard too see it then on Lágu Hvolar. But that suggests that this tremor pulse is in fact quote weak one. Copyright of this picture belongs to Icelandic Met Office.


Harmonic tremor pulse can be seen on this SIL Rjúpnafell. It is more stronger signal then on Álftagröf, so it suggest that the source of this tremor pulse is closer to this station then on Álftagröf. Copyright of this picture belongs to Icelandic Met Office.

All pictures are from 16:28 UTC on 12. June 2011.

On other station around Katla volcano I do not see this harmonic tremor pulse on the Icelandic Met Office on-line tremor chart. But that does not mean that it this tremor pulse is not being detected on other SIL stations around Katla volcano.

The source of this tremor pulse is most likely an dike intrusion at great depth inside Katla volcano that is taking place without any earthquake activity. This has happened before without resulting in an eruption from Katla volcano (besides the event in the year 1999). I do not think that this means an eruption is going to happen soon. But this might signal that Katla volcano is about enter an more activity phase then in last few decades. But if that is going to turn out that way is something that only time can answer.

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Extinct volcanoes in Hungathing Vestra county, Iceland

Here is an picture of how an ~5 million year old extinct volcano looks out. This pictures also show an old dike intrusion that might have gone up to the surface on that time. But I think it is hard to know that for sure, as erosion has changed the landscape a lot over the past 10 million years or so. So it hard to know for sure how deep this magma dike did actually form or if it was connected to an crater on the surface.


About 5 to 8 million years old dike intrusion into sedimentary rock that pre-dates this dike intrusion. I do not know by how much older the surrounding rock actually is. But it has small fossils in them.


The volcano that did create this old dike intrusion. The rocks in the area (old lavas) suggest that this was mostly basalt that did erupt from this volcano. But this volcano was on the old Snæfellsnes-Skagi Rift Zone.


Rift Zones in Iceland. Picture is from Wikipedia. See original copy here along with copyright information. Please note that this picture is NOT completely correct in regards to the facts. But is good for basic illustration of the rift zones in Iceland. Note that this is picture is missing the Skagafjörður Rift Zone (failed rift zone).


Picture of what can be seen of the Snæfellsnes-Skagi rift Zone. (I think it is the correct name for it). The mountain behind it is also an massive old volcano that was active at the same time as this rift zone. The houses there belong to my mon and dad (also on the picture below this one). They run an sheep farm.


Picture of Snæfellsnes-Skagi rift Zone to the north. The same volcano as on picture above can also been seen on this picture. But what is not seen is the third volcano that is in this area (also extinct). But glacier activity did remove all major traces of that volcano long time ago.

I am going to post more pictures of this area during the summer. Even if it is just small part of Iceland, it has an lot of geological history to show. All of it is connected to volcanism and glacier activity over the past 8 million years (or about that) time. Too see full size of the pictures, just click on them.

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Earthquake swarm in South Langjökull volcano and Krýsuvík volcano

Today has been spotted with earthquake swarms in Iceland. This earthquake swarms have not been big so far in both terms of earthquakes and size of the earthquakes. With the biggest earthquakes in South Langjökull volcano (Presthnjúkar). The biggest earthquakes in South Langjökull volcano have been around ML2.5 in size. With the average depth of 10 to 5 km. Total number of earthquakes is something around 39 and that is an small earthquake swarm.

The area in question is known for earthquake activity. Few years ago there was an earthquake swarm in this area with several ML4.0+ earthquakes. This area did also see earthquake swarm earlier this year. So far nothing suggests that an eruption is close in this area.


Map from Icelandic Met Office showing the area with the earthquake swarm. Click on the picture to get full size. Copyright of this picture belongs to Icelandic Met Office.

Krýsuvík volcano did also have an minor earthquake swarm today. The largest earthquake in Krýsuvík volcano was ML2.1 with the depth of 3.9 km. So far this earthquake swarm has been an minor one. With just over 32 earthquakes happening today.

Other earthquake activity in Iceland is currently not an lot. A ML3.1 earthquake took place few days ago in TFZ in an area that commonly has earthquake swarms. That area does not have any volcanoes, so earthquakes there are only connected to faults in the fault lines in that area.

Blog post updated at 23:29 UTC on 7. June 2011.
Blog post updated at 23:35 UTC on 7. June 2011.

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Everything has gone quiet again in Iceland

After the eruption in Grímsfjall volcano last week everything has gone quiet again in Iceland. Earthquake activity is currently low and all earthquake activity in volcanoes remains low at current time.

Because of that I am going to take me an little break until I move to Iceland. Unless something of interest happens in Iceland. Part of this time I am going to in the sun here in Denmark and check out the beautiful ladies that populate Denmark (if you are offended by this, then I am sorry for you). 🙂

For those how want to know about my money status. June is going to be rather broke-ish. So all supported is welcomed. But I am not going to request it specially as I have done before. Thanks for the support all. 🙂

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Eruption in Grímsfjall volcano is over

According to the news at mbl.is the eruption in Grímsfjall volcano did end at 07:00 UTC on the 28. May 2011. But that was when the last harmonic tremor was seen on Icelandic Met Office SIL stations.

There is an lot of volcano as in the area around Grímsfjall volcano. That means it is going to blow easy with the wind in the dry summer.

According to GPS data from Icelandic Met Office. It seems that inflation has started at Grímsfjall volcano again. But it can be assumed that it is going to take several years until next eruption. But if that is going happen we just have too see.

Morgunblaðið news about the end of the eruption.

Goslokin sett klukkan 7 á laugardag (mbl.is, Icelandic)
Grímsvatnagosinu lokið (mbl.is, Icelandic)
Gosinu lokið (Rúv.is, Icelandic)