Month: August 2012

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Earthquake swarm on Kolbeinsey Ridge yesterday (30.08.2012)

Yesterday (30.08.2012) there was an earthquake swarm on Kolbeinsey Ridge. But earthquakes have been taking place there for several weeks already. This earthquake activity seems to be growing in number of earthquakes swarms taking place. In the year 1999 there might have been an dike intrusion or submarine eruption south of Spar Fracture Zone (more details here). Last earthquake swarm that was noticed by the SIL network was exacly two months ago (30.06.2012). My coverage of that can be found here. But it was not in the same place. But that earthquake swarm was south of Kolbeinsey Island, not north of it as was the case yesterday.


The earthquake area in question are the yellow dots north of Iceland on this map from IMO. Copyright of this image belongs to Icelandic Meteorological Office.

What happens next in this area in terms of earthquake activity, or possible volcano activity is hard to impossible to know. As it is really hard to monitor volcanoes and rift zones that are under 2 km deep ocean and good distance from the coast line. However if there is any major earthquake activity in this area. It is going to appear clearly on my geophone network and IMO SIL network in Iceland.

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Glacier flood confirmed from western Skaftárkatli cauldron

Today (30.08.2012) an glacier flood was confirmed from the western Skaftárkatli cauldron. This glacier flood is small as expected. But it did take several days longer to appear from Vatnajökull glacier then expected. Some hydro-thermal activity in Hamarinn volcano (Bárðarbunga volcano) seems to be currently taking place at the moment. But some harmonic tremor spikes have been taking place in the past two hours.


Harmonic tremor pulse can be seen at the end of this tremor plot from IMO. It only lasted for about 30 to 60 min. Copyright of this image belongs to Icelandic Meteorological Office.


Harmonic tremor pulse can be seen at the end of this tremor plot from IMO. It only lasted for about 30 to 60 min. Copyright of this image belongs to Icelandic Meteorological Office.


Harmonic tremor pulse can be seen at the end of this tremor plot from IMO. It only lasted for about 30 to 60 min. Copyright of this image belongs to Icelandic Meteorological Office.

It might be that this harmonic tremor signals are coming from other volcano system then Hamarinn volcano. This type of activity has been seen before in Hamarinn volcano and follows glacier floods from it. Given the activity last year. I cannot rule out volcano activity taking place now in Hamarinn volcano. New episode of harmonic tremor is now starting in Hamarinn volcano. Based on early observations . It seems that current activity is behaving in similar manner as did happen in July 2011 when an minor eruption took place in Hamarinn volcano. If that is the case now remains to be seen. But it should be clear in few hours what is exactly going on in Hamarinn volcano following this glacier flood.

Icelandic news about this glacier flood

Skaftárhlaup kom úr katlinum – myndband (Rúv.is, video)
Hlaupið kom úr vestari katlinum (mbl.is)

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Two earthquakes in Jan Mayen today (30.08.2012)

Today (30.08.2012) Jan Mayen was hit by two earthquakes. The second earthquake was not an aftershock of the first one. But it remains an question if it was triggered by the first earthquake. The first earthquake had the magnitude of Mw6.6 according to EMSC web site. The second earthquake had the magnitude of Mb5.3 according to EMSC. Both earthquakes where felt by Norwegian military and science staff that resides on Jan Mayen.


Location of the Mw6.6 earthquake off the coast of Jan Mayen. As can be seen. This earthquake took place far out in the ocean. Copyright of this image belongs to EMSC.

The second earthquake was less in magnitude. But was closer to the Jan Mayen Island. For that reason it was possibly felt better the first earthquake.


Large view of the second Jan Mayen earthquake. This earthquake had the magnitude of Mb5.3. Copyright of this image belongs to EMSC.


Close up view of the second Jan Mayen earthquake. Copyright of this image belongs to EMSC.


The Mw6.6 earthquake that took place in Jan Mayen. This geophone station is the closest to the earthquake in Jan Mayen. This image is released under CC licence. Please see CC licence page for more details.


The Mw6.6 Jan Mayen earthquake as it was seen on Heklubyggð geophone station. This image is released under CC licence. Please see CC licence page for more details.


The Mw6.6 Jan Mayen earthquake as it was seen on Eyrarbakki geophone station. This image is released under CC licence. Please see CC licence page for more details.


The Mw6.6 Jan Mayen earthquake as it was seen on Skeiðflöt geophone station. The P-wave goes trough something that speeds up it’s arrival. Something that the software that I use cannot account for. That is why the P-wave is in the wrong location. As model vs reality do not match in this case. This happen frequently with my location data. This image is released under CC licence. Please see CC licence page for more details.


I did also record this earthquake in Denmark. Where I now live. This is the most distance that I did record this earthquake. But the distance was around 2000 km. The signal did appear. But I did not record any surface waves as I did in Iceland. Background noise is also higher here in Denmark then in most location in Iceland and it is more constant. This image is released under CC licence. Please see CC licence page for more details.

I did not record the Mb5.3 earthquakes on my geophones. It was just too small for my hardware to detect it. The waveform from the second earthquake was also lost in the surface waves from the first earthquake during this time period. At least when it comes to my hardware as it currently is.

Icelandic news about this earthquake

Jarðskjálfti við Jan Mayen – 6.6 stig (Vísir.is)
Almannavarnir: Ekki miklar líkur á flóðbylgju (Vísir.is)
Jarðskjálfti upp á 6,6 stig (mbl.is)

Norwegian and danish news about this earthquake

Kraftig jordskjelv utenfor Jan Mayen (NRK.no)
Skælv på 6,6 ryster Grønlands østkyst (DR.dk)

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Earthquake in Brennisteinsfjöll volcano / SISZ earthquake zone

Today (30.08.2012) at 11:59 UTC there was an earthquake with the magnitude of ML3.8 (4.2Mw) in Brennisteinsfjöll volcano / SISZ. But SISZ overlaps this area to some extend. So large earthquakes do happen in this area of Iceland on regular basis. This earthquake was felt in Reykjavík area, south Iceland and some part of western Iceland.


The earthquake location and the following aftershocks. Copyright of this image belongs to Icelandic Meteorological Office.

In around 30 aftershocks have been detected in the area. More aftershock activity in this area cannot be ruled out. This earthquake did appear clearly on my geophones all over Iceland.


The earthquake at Eyrarbakki geophone station. This geophone is the closest to the earthquake. The most movement in this earthquake was on an N-S and E-W fault according to my geophones. This picture is released under CC Licence. See licence page for more details.


This is the earthquake as it was recorded on Heklubyggð geophone. It is the second closest geophone station to this earthquake. This picture is released under CC Licence. See licence page for more details.


Here is the earthquake as it did appear on Skeiðflöt geophone. This picture is released under CC Licence. See licence page for more details.


Here is the earthquake as it did appear on Hvammstangi geophone. This picture is released under CC Licence. See licence page for more details.

It is impossible to know for sure what this earthquake activity means. But earthquake activity in this area of Brennisteinsfjöll volcano did stop around 15:49 UTC. No aftershocks did go above 2.0 in magnitude. More earthquakes in this area should not be ruled out in the next few days to weeks.

Icelandic News about this earthquake

Alltaf von á eftirskjálftum (Rúv.is)
Skjálftinn á enda stórs misgengis (Rúv.is)
Verra ef safnið hefði skemmst (Rúv.is)
Skjálftinn hápunktur – ekki fyrirboði (Rúv.is)
Jörð skalf í dag (Rúv.is. Afternoon radio show about this earthquake in Icelandic)
Jarðskjálftasvæðið undir smásjá sérfræðinga (Vísir.is)
Má búast við nokkrum eftirskjálftum (Vísir.is)
Fólk hljóp á dyr í Litlu Kaffistofunni (Vísir.is)
Jarðskjálftinn var 4,6 stig (Vísir.is)
Á þriðja tug eftirskjálfta hefur mælst (mbl.is)
Jarðskjálfti upp á 4,6 stig (mbl.is)
Snarpur jarðskjálfti á höfuðborgarsvæðinu – Stærsti skjálftinn í 3 ár (Pressan.is)
Jarðskjálftafræðingur: Ekki búið að losa um neina spennu að ráði (Pressan.is)

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Low earthquake activity in Iceland

This is not going to surprise anyone how read this blog on regular basis. But earthquake activity and volcano activity in Iceland is minimal those past days. As it has now been for past several weeks. This has sadly lead to less blog post then I like. But I have also been busy. So it has helped in that sense for me. At current rate, the year 2012 is so far the most quiet year that I remember in an long time. I have been monitoring earthquake activity in Iceland more or less since the year 1996.


Current earthquake activity in Iceland on 29. August 2012. As can be seen. Activity is rather slow today. Copyright of this image belongs to Icelandic Meteorological Office.

While it is quiet in Iceland. I am going to work on other articles about other interesting features in Icelandic geology. They won’t be long. But short and as informal as I can make them. This quiet time might last a bit longer then it already has. I would not expect anything else.

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Deflation stops in Krýsuvík volcano

According to Rúv News today. Deflation has stopped in Krýsuvík volcano. But this is the latest chapter in inflation and deflation episodes that have been taking place in Krýsuvík volcano during the past three years. It is unclear what happens next in Krýsuvík volcano. But an new inflation episode should not be ruled out at this point.

Lat inflation episode started earlier this year (2012) and stopped in May. Then an deflation episode started. It stopped sometimes in August 2012. It is impossible to know for sure when an new inflation episode starts in Krýsuvík volcano. But it is my opinion that is going to be soon. But how soon exactly is impossible to know. Inflation episodes in Krýsuvík volcano have been followed by strong earthquakes swarms. So that are the signs of an inflation period having started in Krýsuvík volcano.

Icelandic news about this

Landsigið er hætt í Krýsuvík (Rúv.is)

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Still no glacier flood in Skaftá glacier river

For reasons that are unknown. No glacier flood has yet taken place in Skaftá glacier river. Even if the western Skaftárketill cauldron in Vatnajökull glacier has emptied. It is now expected that Hamarinn eastern cauldron is going to empty it self soon. But when that might happen is impossible to know for sure.


Ice-quake activity continues in Vatnajökull glacier. But that suggests the water is on the move under the glacier. Copyright of this image belongs to Iceland Meteorological Office.

The glacier flood is expected to be small. But it won’t go unnoticed once started. As the glacier river get’s darker and conductivity in the water increases greatly during the flood. I am going to try and keep an eye out for more information on this glacier flood.

Icelandic News about this

Ekkert hlaup hafið (Rúv.is)

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More fine ash in the volcano ash cloud from Eyjafjallajökull volcano eruption then predicted (2010)

Rúv News had an interesting news bit about Eyjafjallajökull volcano this evening. It was about the eruption that took place in the year 2010. While Europe did not get a lot of volcano ash as expected. The amount of fine volcano ash in the air during this period was more then expected. A lot more according to a research into the ash cloud that happened in April 2010. This volcano ash is an danger to air planes and jet engines.


The volcano ash in question. Copyright of image belongs to Birgit Hartinger. Image used with permission.

The amount of fine volcano ash was underestimated by observing satellites. As they did not see this volcano ash clearly or just not at all according to the news about this study. The amount of fine volcano ash in the air at the time was about ten times more then current model predicted during the eruption. This study did use data from 400 observing areas. The study it self is published in Scientific Report. I have not located this study as of yet.


The ash cloud from Eyjafjallajökull volcano in the year 2010. Public domain picture by NASA/NOAA. (I think. Correction are welcomed.)

I am not sure what this means in terms of the flight ban that was in the effect when the eruption took place. But one thing is sure. The areas that where considered free of volcano ash simply might not have been that in reality.

Icelandic news about this

Lítið af gosefnum til Evrópu (Rúv.is, Icelandic)

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Glacier flood has started from west Skaftárketill cauldron in Vatnajökull glacier

Yesterday an glacier flood started form west Skaftárketill cauldron. But that is an hydro-thermal area inside Hamarinn volcano (Bárðarbunga volcano system). The glacier flood is expected to be small. Last year in July there was also an glacier flood from this area of Vatnajökull glacier. But that was due to minor eruption in this area (it was poorly documented by scientists. I do not know why that is). But now it is melt-water from hydro-thermal area that is causing this glacier flood.

But glacier floods like this happen every 1 to 3 years from this area. Following this glacier flood an swarm of glacier-quakes have been detected in this part of Vatnajökull glacier. Flood in western Skaftárkatli might trigger a glacier flood in the eastern skaftárkatli cauldron. But it is not known if that is actually going to happen this time. It is not expected that current glacier flood is going to be a large one. But there is an risk of Hydrogen sulfide poisoning if people are close the glacier river during the glacier flood. So it is not recommend to go close to the glacier river due to this risk. The glacier flood is expected to appear from under Vatnajökull glacier in the next 5 to 6 hours. It is expected to last around 2 to 3 days at most.


Glacier quakes in Vatnajökull glacier following this glacier flood. This glacier quakes are not strong and do not show up on automatic SIL system. Copyright of this picture belongs to Icelandic Meteorological Office.


Glacier quake activity as it appears on SIL seismometers around Vatnajökull glacier. Copyright of this picture belongs to Icelandic Meteorological Office.


Glacier quake activity as it appears on SIL seismometers around Vatnajökull glacier. Copyright of this picture belongs to Icelandic Meteorological Office.


Glacier quake activity as it appears on SIL seismometers around Vatnajökull glacier. Copyright of this picture belongs to Icelandic Meteorological Office.


Click on this image for full size. This plot here shows output from several SIL stations. This image was released by Icelandic Meteorological Office today. Copyright of this picture belongs to Icelandic Meteorological Office.

It is believed that sometimes following this type of glacier floods from this area in Vatnajökull glacier there are small eruptions, or steam events as the pressure on the hydro-thermal system drops . That in turns allows for some magma movement that is powering the hydro-thermal system in this area of Vatnajökull glacier. It is impossible to know for sure if that is going to happen now. But it is good idea to keep an eye-out for such events taking place in Hamarinn volcano. Given the minor eruption that took place there last year.

Here is an comparison of the events that took place last year compared to the events that are currently taking place in Hamarinn volcano.


Harmonic tremor subsiding from Hamarinn volcano on 13. July 2011. The following glacier flood appears clearly on this tremor plot from Icelandic Meteorological Office. Copyright of this picture belongs to Icelandic Meteorological Office.

I was seeing activity to November 2011 after the activity in July 2011.


One of the last harmonic tremor activity that I did see in Hamarinn volcano during the year 2011. But this took place on 7. November 2011. After this point it did go quiet. Copyright of this picture belongs to Icelandic Meteorological Office.

I do not expect any volcano eruption in Hamarinn volcano at this point. But such things are impossible to know for sure. As Hamarinn volcano has not been studied in details until after the year 2011 eruption.

Icelandic news about this glacier flood

Hlaup hafið í Skaftá (Rúv.is)
Verður væntanlega ekki mikið hlaup (Rúv.is)
Hlaup að hefjast í Skaftá (Vísir.is)
Aldrei verið jafnfljótir að sjá hlaupið (Vísir.is)
Skaftárhlaup hafið (mbl.is)

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New earthquake swarm in Katla volcano

This morning at 07:03 UTC on 21. August 2012 an earthquake swarm started in Katla volcano. This earthquake swarm lasted for few minutes with the last earthquake taking place at 07:50 UTC. No harmonic tremor was detected following this earthquake swarm in Katla volcano. Update 1: The largest earthquake in this earthquake swarm had the magnitude of 2.6 at the depth of 0.1 km.


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

It is impossible to know for sure what this activity means. But this might just be normal autumn activity in Katla volcano. I am expecting more earthquake activity in Katla volcano in next few days to weeks.

Icelandic news about this earthquake activity

Skjálfti í Mýrdalsjökli (Rúv.is, Icelandic)
Jarðskjálfti upp á 3,1 stig í Mýrdalsjökli (Vísir.is, Icelandic)
3,1 stigs skjálfti í Mýrdalsjökli (mbl.is, Icelandic)

Blog post updated at 15:18 UTC on 21.08.2012. I have not yet fully recovered from the heat wave. I forgot the important information about this swarm. They have now been added.