Category: Grímsvötn / Grímsfjall

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Few harmonic tremor charts of Grímsvötn eruption

Here are few harmonic tremor charts from the Grímsfjall volcano / Grímsvatn eruption. It can clearly be seen where the eruption looses strength for an few hours. It is also clear when the eruption starts to regain it’s eruption strength again.

The volcanic tremor is best seen on 0.5 – 1Hz band, alongside 1 – 5Hz bands.


Grímsfjall volcano / Grímsvötn SIL station.


Skrokkalda SIL station.


Kalfafell SIL station.


Fagurhólsmýri SIL station.


Kreppurhaun SIL station.


Askja volcano SIL station.

All pictures are from Icelandic Met Office web page. Copyright of this pictures belongs to them.

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Grímsfjall/Grímsvötn volcano eruption update at 21:54 UTC

This is a minor update to the Grímsfjall volcano / Grímsvötn eruption.

Process of the eruption: The harmonic tremor on the SIL stations around Grímsvötn is increasing again after it did drop a little bit down earlier today. Following this the ash plume has again appeared on radar images from Icelandic Met Office. Currently however the ash plume is just around 10 km high. According to the news, the eruption is made out of basalt. But that is a common eruption type for Grímsvötn. The ash cloud is formed when hot magma gets into contact with ice and water and explodes on contact. This eruption is now expected to many times larger then the eruption in Eyjafjallajökull volcano last year.

Ash cloud: The ash cloud does now covers most of Iceland, except the northern part of west Iceland (for the moment) and east Iceland (for the moment) but that is expected to change in the next 24 to 48 hours. Ash has been reported in most town in Iceland. That includes Reykjavík, Akureyri, Selfoss (heavy ash cloud) and more. According to web cameras there is heavy ash fall close to Hekla volcano from Grímsfjall volcano (web camera pointed towards Hekla is here, Eyjafjallajökull is here). Due the ash cloud all flight to and from Iceland has been grounded until this ash clouds goes away.

Earthquakes: Few earthquakes are recorded. But only two earthquakes have been recorded around Grímsfjall volcano and close to in the past few hours. But that does not mean that they are not happening. But they might simply be lost in the harmonic tremors from the eruption.

Other: Nothing at the moment.

Please note that information here might get outdated really fast and with no warning at all!

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Grímsfjall/Grímsvötn volcano eruption update at 16:02 UTC

Here is the second update today of the Grímsfjall volcano. But it is also known as Grímsvötn.

Process of the eruption: The eruption has not changed a lot since this morning. But its power has dropped a little bit since it started yesterday. But there also seems to be the case that this eruption increases on regular basis. But it is impossible to know for how long that eruption pattern is going to continue in Grímsfjall volcano. Early estimates of this eruption (reported by the news in Iceland) is that this eruption is about 10 times bigger then the eruption in Eyjafjallajökull volcano. But that is a early estimate and is a subject to a change. But in general there is nothing to suggest that this eruption is slowing down, even if it does not have the same power as it did in the first few hours of eruption.

Ash cloud: The ash cloud has dropped a little from it’s high of 20 km. Current measurements place the hight of the ash cloud around 15 to 18 km high up. Reports say that the lowest point was around 10 km, before the ash cloud did get higher again. Update 1: There have been recorded over 15,000 lightnings in this eruption alone. But they where recording 2198 lightning in 1 hour since the eruption started. News about it can be found here (Icelandic, picture). Update 2: The ash cloud is now from 10 to 20 km high. But it depends on the power of the eruption. But that seems to change over time and does not remain a constant.

Earthquakes: So far, most of earthquake activity in Grímsfjall volcano has stopped. But that suggest that the magma now has a clear path to the surface. There has been some earthquake activity in Hamarinn volcano. But it is unclear if that is connected to the eruption in Grímsfjall volcano.

Other: It is dangerous to go into the ash cloud. The government has closed off part of road one due the ash cloud. People how find them self in the ash cloud should find a shelter soon as possible, or of they are inside a house they should remain there. Reports are of communication problems where the ash clouds goes over due to static charge in it. This interferes with GSM, 3G phones, radios and tv receptions. In worst cases people can not expect a reception of any radio signal where the ash cloud is most dense.

Sorry for lack of links. I do not have the time to post them into this blog post.

Please note that information here might get outdated really fast and with no warning at all!

Updated at 16:17 UTC.
Updated at 16:26 UTC

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Grímsvötn/Grímsfjall volcano eruption update at 08:52 UTC

This is a short update on Grímsfjall volcano/ Grímsvötn eruption. This is short update because a lot of details in this eruption are still unclear at this moment.

Process of the eruption: The eruption in Grímsvötn is still growing strong. Icelandic Met Office SIL sensors show a uneven process in the eruption. But they also show that the eruption has dropped a little bit in power since it originally started in yesterday. That is normal for a eruption in Grímsfjall volcano. It starts strong and then slowly drops in power over time. But what is unusual for this eruption is the uneven process that is taking place (seen with SIL data) in the eruption. What that means is unclear. It is more unclear what it means to the eruption. While it is unclear at the moment. It appears that the eruption is taking place a little south of the eruption in the year 2004. But that is unconfirmed, as ash cloud to the ground blocks the view the eruption site.

Ash cloud: The ash plume is reported to have reached 20 km high yesterday. From as I can gather that has not changed. This ash plume appears be made from two to three ash cloud columns. With the strongest one getting the highest. A lot of lightning is taking place in the ash cloud. Due to the ash cloud, all flight from and to Iceland has been cancelled until further notice (don’t ask question about that here, ask your airliner for information about this closure). The ash did start to fall in populated areas few hours after the eruption did start in Grímsvötn. The ash is described as fine, but more crude (bigger particles) then the ash from Eyjafjallajökull volcano eruption in the year 2010. The ash cloud is moving west in higher layers of the atmosphere over Iceland. While it moving south in the lower layers of the atmosphere as the wind is from north in Iceland at the moment.

Earthquakes: After the magma has found it’s way to the surface. All earthquake activity did stop in Grímsfjall volcano. This is normal. But what is unusual is that there have been few earthquake swarm after that in Grímsfjall volcano. I do not know what it means or why this is happening. But this is interesting development.

Other: The earliest estimation on the size of the Grímsfjall volcano eruption 2011 is that this looks like it is a bigger eruption then in Eyjafjallajökull volcano eruption in the year 2010. But that is closer to speculation based on visual observation of the eruption. But it is clear that this eruption is bigger then the year 2004 eruption in Grímsfjall volcano.

A new video has been relased of the eruption. It is from yesterday when the eruption was starting.

Update 1: They now say that this is the largest eruption in Grímsvötn / Grímsfjall volcano in the last 100 years. Rúv news about this, Stærsta gos í Grímsvötnum í 100 ár (Icelandic).

Please note that information here might get outdated really fast and with no warning at all!

Update at 09:24 UTC.

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Ash cloud confirmed from Grímsfjall volcano

A eruption ash cloud has been confirmed from Grímsfjall volcano. I do not know how high it currently is. But Icelandic news is reporting that the cloud is rising fast and high (estimated 3000 – 4000 meters and rising). Explosions have been seen from good distance.

Update 1: They estimate that there are 10 to 12 hours until the glacier flood appears from this eruption. The ash cloud can be tracked with lighting map here.

News about this.

Strókur rís hátt yfir Grímsvötnum (Rúv.is, picture)
Tíu til tólf klukkutímar í hlaup (Rúv.is, new picture)
Allir viðbragðsaðilar komnir af stað vegna gossins (Vísir.is, Picture)
Mjög öflug gosstöð (mbl.is, New picture)

Updated at 19:41 UTC.
Updated at 19:53 UTC.
Updated 20:21 UTC.

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Sharp increase in harmonic tremors in Grímsfjall volcano

Something is happening at Grímsfjall volcano. The SIL seismomter on Grímsfjall volcano is shows a sharp increase in harmonic tremors in Grímsfjall volcano. It also appears that earthquake activity in increasing in Grímsfjall volcano.

I do believe (based on the data so far) that a eruption is about to start in Grímsfjall volcano. I am going to post more updates on this when I know more. But please note that I might be wrong. But this is what the data suggests so far.

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Quiet scene goes into third week

The quiet scene that has been taking place in Iceland over the last two weeks is still ongoing and is now entering it’s third week. Over the last two week there have been less then 300 earthquakes during a single week. In Iceland that is quiet.

All volcanoes in Iceland have mostly been quiet. But there was a unconfirmed earthquake swarm in Grímsfjall volcano. But due to extremely bad weather it was not observed properly by the SIL network. North of Iceland there also has been a unconfirmed earthquake swarm. This earthquake swarm is somewhere north of Kolbeinsey volcano. But due to distance and bad weather it is unknown how big it was. But the largest earthquakes that have appeared on the SIL network did manage to go up to ML3.0 in size. But that is mostly a underestimate on the size of this event. But underestimate on a earthquake size happens when it is far from SIL network and not properly recorded due that.

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Overview of the earthquake activity in Grímsfjall volcano

Here is a short overview of the activity in Grímsfjall volcano in Week 08 and Week 13 for a comparison. A quick review of the earthquake data on the Icelandic Met Office web page suggests that the current path to a eruption started in Week 07.

It is clear on the pattern that has been evolving over the past four to five weeks where the eruption is most likely going to happen. That location is almost directly below the SIL station that Icelandic Met Office.


Week 08. Picture is from the Icelandic Met Office. Copyright of this picture belongs to Icelandic Met Office. Click on the picture to get full size.


Week 13. Picture is from the Icelandic Met Office. Copyright of this picture belongs to Icelandic Met Office. Click on the picture to get full size.

The evolving cluster of earthquakes can clearly be seen in this week overviews, and other in between them (Week 07 to week 13). It is clear that the magma has found a collection spot inside Grímsfjall volcano. But the question remains where it is going to break it self when a eruption starts. It is rather that question rather then when it happens, given the earthquake pattern that I am seeing coming from Grímsfjall volcano at current time.

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Two earthquakes in Grímsfjall volcano

This two earthquakes did happen in Grímsfjall volcano today. There signature clearly shows that they are created by magma breaking the crust. The background noise (SIL tremor plot) in Grímsfjall volcano also appears to have changed following this two earthquakes. I am not sure why that it. But this two earthquakes might be a pre-sequence to a eruption in Grímsfjall volcano. But it is hard to be sure on that at this moment. But I am sure that it is getting shorter to a eruption in Grímsfjall volcano.


Unallocated earthquake, most likely from Grímsfjall volcano. This picture is released under Creative Commons Licence. See link at top for more information.


Unallocated earthquake. This earthquake is from Grímsfjall volcano. The automatic size is ML2.9. With the depth of 1.1 km. This picture is released under Creative Commons Licence. See link at top for more information.

If anything more interesting happens at Grímsfjall volcano. I am going to post more information about it soon after it happens.