Category: Grímsvötn / Grímsfjall

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Earthquake activity east of Grímsey Island (TFZ). Possible fake earthquakes in Eyjafjallajökull volcano

At 03:03 UTC an earthquake with the early and unconfirmed magnitude of ML3.3 took place east of Grímsey Island. This earthquake did take place on TFZ. It is possible, but this earthquake might be the start of an earthquake swarm in this area. But that is not uncommon pattern for earthquakes in this area. But however it also happens that earthquakes like this one takes place. But then nothing more happens.


Earthquake activity in TFZ. The early magnitude ML3.3 earthquake is marked with a green star. Copyright of this image belongs to Icelandic Meteorological Office.

Eyjafjallajökull volcano

There has also been some earthquake activity in Eyjafjallajökull volcano during the night. This activity is possibly false due to weather or faulty SIL seismometer. The earthquake that have been detected so far have extremely low quality. But the increases the chance of them being false, rather then real events. It is not going to get known if this activity is real or not until it is reviewed by seismologist at Icelandic Meteorological Office.


The possible earthquake activity in Eyjafjallajökull volcano. This activity might be due to faulty hardware or weather, rather then real activity in Eyjafjallajökull volcano.Copyright of this image belongs to Icelandic Meteorological Office.

Eyjafjallajökull volcano has been quiet since it’s eruption in the year 2010. I do not expect that to change any time soon. Since it seem that Eyjafjallajökull volcano eruption cycle is around 150 to 500 year (theoretical maximum in my opinion). So I am not expecting anything to happen in Eyjafjallajökull volcano any time soon. If this earthquake activity is confirmed it is interesting. What might come out it is impossible to know for sure.

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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.

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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)

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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)

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Minor earthquake activity in Iceland

During the past few weeks it has been quiet in Iceland. Really quiet, with almost nothing going on. It is still like that to some extent. So this is just a short overview of the small activity that has been taking place in Iceland during the past 48 hours or so.


The earthquake activity in Iceland during the past 48 hours. Copyright of this image belongs to Iceland Met Office.

The most activity in the last 48 hours have been on the Reykjanes and on TFZ. But there was an small earthquake swarm in each area. With earthquakes that did not get over ML2.5 in size so far. Two earthquakes where in Askja volcano. One in Grímsfjall volcano fissure system (maybe in Þórðarhyrna volcano).


Earthquake west of Hekla volcano, in the SISZ. This picture is released under Creative Common Licencee. See the licence page for more detail.

Katla volcano

During this winter. Katla volcano has been quiet. This is somewhat normal, as more snow means more ice-mass on top of the volcano. But now that has started to melt a little and that means less ice-mass on top of the volcano. That could mean more activity in Katla volcnao during the next few weeks. So far however the activity remains small and there are no special earthquakes to report.


Earthquake activity in Katla volcano, on this picture earthquake activity west of Hekla volcano can also been seen here. Copyright of this image belongs to Iceland Met Office.

The earthquakes west of Hekla volcano belong to the SISZ fault area. Not Hekla volcano it self. What is also interesting is the earthquake activity in south part of Katla volcano. In area outside of the glacier. This are small earthquakes, that do not appear on my geophone. Even if they are close to it. I am unsure what this means for the future. But it is worth keeping an eye on it.

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Grímsfjall volcano continues to prepare for a new eruption

As I did mention in a blog post from 16. January 2012. Grímsfjall volcano is preparing for a new eruption. That progress has not slowed down at all. I am rather sure that the eruption prepare progress in Grímsfjall volcano has sped up. But this is nothing confirmed at the moment. I am just noticing slow increase in earthquakes from Grímsfjall volcano.


Today’s activity in Grímsfjall volcano. Copyright of this picture belongs to Iceland Met Office.


Grímsfjall volcano activity in Week 11 2012. Copyright of this picture belongs to Iceland Met Office.


Grímsfjall volcano activity in Week 12 2012. Copyright of this picture belongs to Iceland Met Office.

It is impossible to know for sure when next eruption starts in Grímsfjall volcano. But at the current time, the clock is ticking down faster then it did before in my opinion. As is known from history. Grímsfjall volcano has erupted sometimes the year after. Even after a big eruption. As was the case last year (2011), when it had the largest eruption in 140 years.

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List of known eruptions in Grímsfjall volcano and connected volcanoes

Here is an list of eruptions in Grímsfjall volcano and Þórðarhyrna volcano based on data from Global Volcanism Program and documented eruptions. In most cases, eruptions that took place in the early 10 to 16th century are poorly documented if they where smaller eruptions. This even goes on somewhat into the 20th century.

Year ~8230BC +-50 years. Area of activity, unknown. Size VEI=6. Known as Saksunarvatn tephra layer. Dating done with Radiocarbon (corrected).

Year ~4550BC +-500 years. Area of activity, Laki. Size VEI=0. Dating method, Tephrochronology.

Year ~3550BC +-500 years. Area of activity, S of Þórðarhyrna. Dating method, Tephrochronology.

Year ~1950BC +-100 years. Size VEI=2 Area of activity, Raudholar and Brunuholar. Dating method, Tephrochronology

Year ~50BC. Size VEI=2. Area of activity, Halsagigur. Dating method, Tephrochronology

Year ~910AD. Area of activity, ?. Dating method, Tephrochronology.

Year ~960AD. Area of activity, ?. Dating method, Ice core.

Year ~1010. Area of activity, ?. Dating method, Ice core.

Year ~1060. Area of activity, ?. Dating method, Tephrochronology.

Year ~1090. Area of activity, ?. Dating method, Ice core.

Year ~1150. Area of activity, ?. Dating method, Ice core.

Year ~1190. Area of activity, ?. Dating method, Ice core.

Year 1230 +- 10 years. Area of activity, ?. Dating method, Ice core.

Year 1270 +- 10 years. Area of activity, ?. Dating method, Ice core.

Year 1290 +-10 years. Area of activity, ?. Dating method, Ice core.

Year 1310 +-10 years. Area of activity, ?. Dating method, Ice core.

Year 1332, November. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1341, May. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year ~1350. Area of activity, ?. Dating method, Ice core.

Year ~1354. Area of activity, ?. Dating method, historical documents.

Year 1369. Area of activity, ?. Dating method, Ice core.

Year 1370 +-10 years. Area of activity, ?. Dating method, Ice core.

Year 1390 +-10 years Area of activity, ?. Dating method, Ice core.

Year 1430 +-10 years. Area of activity, ?. Dating method, Ice core.

Year 1450 +-10 years. Area of activity, ?. Dating method, Ice core.

Year ~1469. Area of activity, ?. Dating method, Ice core.

Year 1470 +- 10 years. Area of activity, ?. Dating method, Ice core.

Year ~1471. Area of activity, ?. Dating method, Ice core.

Year 1490 +- 10 years. Area of activity, ?. Dating method, Ice core.

Year ~1500. Area of activity, ?. Dating method, Ice core.

Year ~1509. Area of activity, ?. Dating method, Ice core.

Year 1510 +- 10 years. Area of activity, ?. Dating method, Ice core.

Year 1521 +- 10 years. Area of activity, ?. Dating method, Ice core.

Year 1530 +- 10 years. Area of activity, ?. Dating method, Ice core.

Year 1598. November 7. Area of activity, ?. Size VEI=3?. Dating method, historical documents.

Year 1603. October 31. Area of activity, possibly Grímsvötn. It is unclear. Dating method, historical documents.

Year 1610. Area of activity, ?. Dating method, Ice core.

Year 1619. July 29. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year ~1622. Area of activity, ?. Dating method, Ice core.

Year 1629. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1632. Area of activity, ?. Dating method, Ice core.

Year 1638 February 24 +- 4 days. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1659 November. Area of activity, ?. Size VEI=?. Dating method, historical documents.

Year 1681 April 10. This might not be an eruption in Grímsfjall volcano.

Year 1684 November 5 +- 4 days. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1697. Area of activity, ?. Size VEI=?. Dating method, historical documents.

Year 1706 October 15 +- 45 days. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1716 October 6. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1725 February. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1730. Area of activity, ?. Size VEI=?. Dating method, historical documents.

Year 1753 October 15 +-45 days. Area of activity, ?. Size VEI=2?. Dating method, historical documents.

Year 1768. This eruption might not have taken place in Grímsfjall volcano.

Year 1774. Area of activity, ?. Size VEI=?. Dating method, historical documents.

Year 1783 to 1785 May. Stop date May 25 1785. Area of activity, Laki, Lakagígar. Size VEI=4+. Dating method, historical documents.

Year 1794. Eruption might not have been in Grímsfjall volcano. Somewhere in West Vatnajökull.

Year 1816 May. Area of activity, ?. Size VEI=?. Dating method, historical documents.

Year 1823 February 4 +-4 days. Area of activity, Grímsvötn-Þórðarhyrna. Size VEI=2. Dating method, historical documents.

Year 1838 June. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1854. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1861. This eruption is uncertain.

Year 1867 August 29. Area of activity, ?. Size VEI=1. Dating method, historical documents.

Year 1873 January 8, it ended in August. Area of activity, ?. Size VEI=4. Dating method, historical documents.

Year 1883 January 15, it ended in April 15 +-5 days. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1887 August 15, it ended in the year 1889. Area of activity, Þórðarhyrna. Size VEI=2. Dating method, historical documents.

Year 1891 November, it ended in March 16 1892. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1897. Location of this eruption in uncertain. Area of activity, ?. Size VEI=2. Dating method, ?.

Year 1902 December, this eruption ended in the year 1904 on 12 January. Area of activity, Grímsfjall and Þórðarhyrna. Size VEI=4. Dating method, historical documents.

Year 1910. Area of activity, ?. Size VEI=?. Dating method, ?.

Year 1919. This eruption is uncertain.

Year 1922 September 29 +-1 day. This eruption ended on October 23. Area of activity, ?. Size VEI=2. Dating method, historical documents.

Year 1933 November 29 +-1 day. This eruption ended on December 9 +-1 day. Area of activity, North of Grímsvötn Caldera. Size VEI=1. Dating method, historical documents.

Year 1934 March 30, this eruption ended on April 7 in the year 1934. Area of activity, Close to south caldera wall. Size VEI=2. Dating method, historical documents.

Year 1934. This eruption is uncertain. But it took somewhere in Vatnajökull glacier.

Years 1938 May. Area of activity, 8 km south of Svartibunki. Size VEI=1. Dating method, historical documents.

Uncertain eruptions the years 1939 June, 1941 April, 1945 September 25, possible VEI=1 eruption, 1948 February.

Year 1954 January 15 +-45 days. Area of activity, ?. Size VEI=1. Dating method, historical documents.

Year 1954 July, this eruption is uncertain. Area of activity, north and south part of the caldera. Size VEI=1?. Dating method, historical documents.

Year 1972 March. This eruption is uncertain.

Year 1983 May 28. This eruption ended on June 2. Area of activity, close to the south part of the caldera wall. Size VEI=2. Dating method, historical documents.

Year 1984 August 20 (or around that date). This eruption is uncertain.

Year 1996, September 30. This eruption ended on November 6. Area of activity, Gjálp fissure. Size VEI=3?. Dating method, historical documents.

Year 1998, December 18. This eruption ended on 28 December. Area of activity, South Caldera wall. Size VEI=3. Dating method, historical documents.

Year 2004 November 1. This eruption ended on November 4. Area of activity, South West and east sides of the caldera. Size VEI=3. Dating method, historical documents.

Year 2011, May 21. This eruption ended on May 30. Area of activity, South West part of the caldrea. Size VEI=3. Dating method, historical documents.

This is just short overview of the eruptions that have taken place in Grímsfjall volcano and in Þórðarhyrna volcano. It does not contain a lot of details on them. Please not that this blog post might contains errors. If you see them. Please comment on them and I am going to fix them soon as I can.

This blog post is going to be updated with time.

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Historical eruption of Grímsfjall volcano of the year 1783 to 1785

The year 1783 is something that is going to live in historical memory of the Icelandic people for long time to come. The historical memory of Icelanders still remember the eruption of Laki that took place 229 years ago. This eruption is among Iceland biggest eruption in historical times and since Iceland got populated around the year 600 (or around that time, according to new data). It is unclear when the exact eruption started in Grímsfjall volcano and in Þórðarhyrna volcano (a smaller volcano south-west of Grímsfjall volcano, it is inside Grímsfjall volcano fissure swarm). But what is known is that this eruption started sometimes in May.

The eruption started in Grímsfjall volcano it self, it is unclear where exactly it started. Creating a glacier flood that did go down Þjórsá that same month in some part. But was documented that Þjórsá was darker and had worse smell then normally and had more water in it. It was also documented that Skaftá did have more water in it and was darker and had bad smell early spring in Iceland (that means late April or early May). But the glacier flood that must have taken place after an eruption started are not well documented in history best to my knowledge. From what I can read it seems that the eruption of Grímsfjall volcano started in the main volcano (unknown where exactly). The years 1755 and to the year 1785 seems to have been extremely active in terms of volcano activity in Iceland. But that year there was also an eruption on the Reykjanes Ridge that created a short lived Island. It did however only last few months at the best. It is possible that the eruption on the Reykjanes Ridge was in the area of Eldey or close to it. But it is impossible to confirm it for sure.

It is not known when the actual eruption started in Grímsfjall volcano or in Þórðarhyrna volcano. But it has been assumed from what I can gather that Þrórðarhyrna volcano was also erupting during this eruption. But the reason for that might well be due to dike intrusions from Grímsfjall volcano might have started an eruption in Þórðarhyrna volcano. But best to my knowledge, there have not been many eruptions in Þórðarhyrna volcano since the eruption in the year 1783 (or around that time).

According to documented history, the fissure eruption started around 8. June 1783. This fissure eruption had growing earthquake swarms before it took place. This was due (but they did not know this at the time for obvious reasons). When the eruption started, it started with a large ash cloud that did go down Skaftárhrepp and nearby area. Following this ash cloud was a lot of gas pushing up with the erupted material. But blue haze was reported in historical documents about this eruption. The problem with the carbon-monoxide did not get any better . Given the year this did happen, there are holes in the event as they did happen. But by 12th of June 1783 the lava had already filled several canons at least and had already destroyed a lot of farmland and farms. But it is documented that lava bombs where known to have been found up to 112 km distance from the eruption. The total fissure length is around 25 km long. It is among Iceland longest eruption fissure in historical times. But Askja volcano had an fissure eruption that was around 20 km long in its eruption episode around the year 1875 to the year 1961, when it took a break that is continuing to this day.

Based on historical documents. It seems that this eruption had two phases. The the first one started with an eruption in the south part of what is now the eruption fissure of Laki. The second one was when eruption craters did open up north part of the fissure after several months of eruption on the south part of the eruption fissure. But by that time the eruption had already diminished in strength at the same time, or before that. It is hard to know from historical documentation what actually did happen at this time. But the eruption is believed to have stopped on 26 May 1785.

Many of the eruption craters did make ash, not lava. The ash layers from those craters where up to 2 meters thick at the distance of 500 meters in some areas. It is also believed that the eruption strokes from many of the craters where up to 800 to 1400 meters high when they where at the tallest. During this eruption there was a sour rain, along with other deadly effects that did follow this eruption. It did also happen during this eruption that many animals did die due to ash poisoning, and gas poisoning from the eruption. Just as humans did at this time. But at this time Iceland did not have any functional government that was able to handle this type of natural disaster. The amount of volcanic gases also had effects around northern hemisphere. But this effects did create huge problems in Europe, Canada, U.S and in Russia from best of my knowledge (it might however not be correct).

Many people might believe that after such a big eruption Grímsfjall volcano would stop for a long time. This was not the case. Only 22 years after the major eruption of the year 1783 to 1785 Grímsfjall volcano had an new eruption. This was smaller, only having the VEI scale of 2. But Laki eruption has the VEI scale of 4+. Before the Laki eruption, there had been an other eruption in the year 1774, but it was an minor VEI=2 eruption. Last eruption in Þórðarhyrna and Grímsfjall volcanoes was in the year 1902. That was an VEI=4 eruption that lasted from December 1902 and until January 1904.

For this reasons I classify Grímsfjall volcano (including also Þórðarhyrna volcano) one of the dangerous volcanoes in Iceland. I do think it might be even be more dangerous the Katla volcano all considered. But this is just my personal opinion and nothing else.

Based on following references

Skaftáreldar 1783 (Icelandic)
Grímsvötn (Icelandic)
The eruption that changed Iceland forever (BBC News)

Blog post updated at 01:49 UTC on 22.03.2012.

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Update on Grímsfjall volcano glacier flood

During the past several hours the amount of water in the glacier flood from Grímsfjall volcano has not dropped a lot, but this glacier flood started two days ago (27.01.2012 around 12:00 UTC). But that might be down to heavy rain in the area. Normally a glacier flood from Grímsvatn lake (inside the Grímsfjall volcano caldera) last for about one to two days during a normal glacier flood. It is believed that this glacier flood is from Grímsfjall volcano glacier lake. But it might be hard to confirm this during this time of the year.


Possible noise from the glacier flood on this SIL station. This might however be increased noise due to heavy rain on it. Copyright of this picture belongs to IMO.

I have known for some time now that Grímsfjall volcano is preparing for a new eruption. This I know because of the increase in earthquake activity and increased hydro thermal activity in Grímsfjall volcano. So far there is nothing that suggest that Grímsfjall volcano is going to erupt this time around, at least for the moment. I am expecting this glacier flood to be over in the next several hours. No earthquakes have happened in Grímsfjall volcano during this glacier flood. I do not expect them to take place unless magma starts moving inside Grímsfjall volcano. Be that dike intrusion or start of an eruption.

Icelandic news about the glacier flood.

Óbreytt ástand í Gígjukvísl (mbl.is)
Sama vatnshæð í Gígjukvísl (Rúv.is)
Vatnshæð hélst óbreytt í nótt (Vísir.is)

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Glacier flood from Grímsvatn lake on Grímsfjall volcano

It has just been announced in the news that Grímsvant glacier lake has just had an glacier flood, but this lake is in the Grímsfjall volcano caldera. This glacier flood is believed to have started yesterday around 12:00 UTC. The glacier river that the water is running into is called Gígukvísl. So far this appears to be minor flood so far. But I do not know how much water as in Grímsvatn lake when this flood did take place.

At current time it is impossible to know if an eruption is going to take place following this glacier flood from Grímsvatn lake in Grímsfjall volcano.

I am going to post more information about this as I get them.

Icelandic news about this. Use Google Translate if you want to get incomprehensible news about this event.

Líklegt að Grímsvötn hafi hlaupið (Vísir.is)
Hlaup í Gígjukvísl (Rúv.is)
Jökulhlaup í Gígjukvísl (mbl.is)