Monitoring – Page 91 – Iceland geology

August 26, 2016

Minor earthquake swarm on Tjörnes Fracture Zone (TFZ)

Today (26-August-2016) a minor earthquake swarm started on TFZ. This is currently not a large earthquake swarm and only around 50 earthquakes have happened so far. More earthquakes might happen if this earthquake swarm continues.

The minor earthquake swarm is shown by the cluster of red dots. Copyright of this image belongs to Iceland Met Office.

This area has seen several earthquake swarm since July and is a high chance earthquake activity is going to continue in this area for the next few days to weeks. Earthquakes with magnitude above 3,0 cannot be ruled out.

August 23, 2016

Small glacier flood from Grímsfjall caldera lake

On the 18th of August 2016 a small glacier flood started from the Grímsfjall volcano caldera lake. This is a tiny glacier flood according to the news, with the glacier on top of the lake only having dropped around 5 meters so far.

Minor glacier flood as it appears on Grímsfjall volcano SIL station. Copyright of this image belongs to Iceland Met Office.

This glacier flood is going into Gígjukvísl glacier river, at the moment Iceland Met Office doesn’t think there is any major danger from this glacier flood. The biggest risk at the moment is from volcano gases that have dissolved into the water and get released when the pressure drops of the water. The glacier water is already in Gígukvísl glacier river, no major changes are expected in that river due to how small this glacier flood is.

Iceland News

Lítið jökulhlaup hafið úr Grímsvötnum (Rúv.is, Icelandic)
Jökulhlaup hafið úr Grímsvötnum (mbl.is, Icelandic)

August 19, 2016

Earthquake activity in Katla volcano

Today (19-August-2016) a magnitude 3,5 earthquake took place in Katla volcano. It was followed by several earthquakes, both before the strongest earthquakes and after it.

The earthquake activity in Katla volcano. The green star shows the location of the magnitude 3,5 earthquake. Copyright of this image belongs to Iceland Met Office.

This doesn’t seems to be an activity connected directly to magma movements. This might however be a gas under pressure breaking rock, since clues this summer suggests that heat is now increasing in the caldera. At least for now, it might cool down again in coming months. The most common months for Katla volcano to erupt are from July until November, eruptions in other months are less common, they do happen every few hundred years.

The magnitude 3,5 earthquake as it appeared on my geophone in Heklubyggð. This image is under Creative Commons licence. Please see the CC Licence page (above) for more details.

July 11, 2016

Small glacier flood from Mýrdalsjökull glacier

A small glacier flood started from Mýrdalsjökull glacier few days ago. The most risk is from sulphur gases and other gases from the glacier flood that might be concentrated in lower areas. There is also a minor risk of the flood destroying walking path bridges in the area it goes over. This glacier flood might go into Emstruá river and there is the risk of destroying walking path bridges in the area. No other risk is expected from this minor glacier flood from Mýrdalsjökull glacier. This is a normal summer release of hydrothermal water from the glacier. Happens every other year and sometimes every year.

July 5, 2016

Earthquakes between Bárðarbunga and Grímsfjall volcanoes

Today (05-July-2016) at 05:56 UTC an magnitude 3,4 earthquake took place between Bárðarbunga and Grímsfjall volcanoes.

The green star is the magnitude 3,4 earthquake between Bárðarbunga and Grímsfjall volcano. Copyright of this image belongs to Iceland Met Office.

This earthquake suggests that an complication is on the way. The question here is if an interaction between Bárðarbunga volcano and Grímsfjall volcano is on the way. Since both volcanoes are preparing for an eruption. [Speculation!] All that I get from my models (in my mind, since I don’t have the computer power or the skills to make them PC friendly at the moment) is confusion. At worst a magma dyke from either Bárðarbunga volcano might enter Grímsfjall volcano or an dyke might come from Grímsfjall and enter Bárðarbunga volcano (hint: A result of either of such event is rather catastrophic eruption, even if just for a short time). What can also happen is nothing, just earthquakes and nothing more. However, increase in the earthquake activity at this location suggests that no such luck is on the way. When and if such event happens is impossible to know, what can be done is to keep monitoring, day and night. This is going to happen the when and the way it wants to happen, all that can be done as humans is to wait and see. [/Speculation!]

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July 5, 2016

Earthquake swarm north of Kolbeinsey Island

Today (05-July-2016) an earthquake swarm took place far north of Kolbeinsey Island. Earthquake activity in this area of the ocean has been increasing over the past few months. It’s unclear what is going on at the moment.

The earthquake activity north of Kolbeinsey Island. Copyright of this image belongs to Iceland Met Office.

Largest earthquakes in this swarm had the magnitude around 2,9 – 3,4. Good magnitude estimate is not possible due to the distance from the SIL network. What exactly is going on at this location is unclear. I do not rule out any eruption activity at this location when earthquake swarms take place. This might also just be normal earthquake swarm without any eruption connection. The depth of the ocean at this location is around 3 – 5 km.

June 30, 2016June 30, 2016

Deep earthquakes in root of Eyjafjallajökull volcano

Today (30-June-2016) three earthquakes took place in the root system of Eyjafjallajökull volcano I think. The most depth for those earthquakes was 14,3 km and the most shallow one 1,3 km. The largest magnitude was 1,1 the other two earthquakes had the magnitude of 0,7. Nothing to worry about magnitude wise.

The earthquake activity close to Eyjafjallajökull volcano (three yellow dots). Copyright of this image belongs to Iceland Met Office.

Eyjafjallajökull volcano extends to this area, however at this area there are no surface craters. If there where they are long lost due to erosion. Unlike many other volcanoes, Eyjafjallajökull volcano does not have an extensive fissure swarm extending outwards for it, that should limit the path the magma can travel in theory. While I am not expecting any type of eruption from Eyjafjallajökull volcano in near future. If this earthquake activity continues I might have to review that outlook. I don’t expect this earthquake activity to continue, since next eruption in Eyjafjallajökull volcano won’t happen (based on my model) until the year 2199 at the earliest.

It is also question of this earthquake activity belongs to Vestmannaeyjar volcano system. Over the past few years deep earthquakes have been taking place there at regular time. Not many, just one or two at the time.

June 25, 2016

Something is going on in Bárðarbunga volcano

This is little short on details as of yet. There is clearly something going on in Bárðarbunga volcano. I don’t know what at the moment, several earthquakes have appeared, the strongest one with the magnitude of 4,0 so far. I’ll post more updates soon as I know more.

The earthquake activity in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

No volcanic harmonic tremor has been seen as of yet. That means no eruption for the moment.

June 23, 2016

Bárðarbunga volcano continues to inflate, gas readings unchanged

According to news report on Vísir.is (Icelandic), it appears that Bárðarbunga volcano is continuing to inflate at the same rate as it has been doing since the eruption ended in Holuhraun in the end of February 2015. Gas measurements from cauldrons that formed on the caldera rim during the eruption in 2014 show that gas output from Bárðarbunga volcano have not dropped during the last year and continue to be high. The glacier drop that formed during the eruption is now almost full of new glacier and snow from last winter. Nothing suggest that water has been collecting at the caldera bottom during the last two years.

The research trip to Bárðarbunga volcano was taken during the days of 3 – 10th of June. A new seismometer was also installed on the caldera rim. I don’t know if it’s a SIL station or not. If it is, it is going to appear soon on Iceland Met Office website.

June 23, 2016

Deep earthquake activity in Katla volcano

Today (23-June-2016) a deep earthquake swarm took place in Katla volcano. None of the earthquakes that took place where strong, but many of them where deep. The deepest earthquake had the depth of 28 km, at this depth it’s only magma that creates earthquakes.

The earthquake activity in Katla volcano. Copyright of this image belongs to Iceland Met Office.

Other interesting feature that showed up is a dyke intrusion in the caldera wall to the south, it is located almost directly north of Vík í Mýrdal village. This dyke intrusion appeared in 2011 after the minor eruption in July that year (this is my view, at the moment it has not been approved by scientists). It is unclear how this dyke intrusion is evolving, but there might be some risk of eruption from it if the pressure increases. Currently there is nothing that suggests an eruption is about to happen.

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