Magma – Page 72 – Iceland geology

August 28, 2014August 28, 2014

Update on Bárðarbunga and Askja volcanoes at 13:34 UTC

This is a none picture update on Askja and Bárðarbunga volcanoes. The reason for this none picture update is that I haven’t had time to work on the images yet. This is the first time this has happened in Iceland since modern recording started. What is going to come out of this I do not know yet.

If you are in the area. Please don’t go into the closed area. There are fines for during so and it is also extremely dangerous since we don’t know properly what happens and risk of sudden flood is high and growing. Eruption might start at any time without warning, both outside the glacier and inside the glacier. If an eruption takes place in a glacier covered area, that means sudden glacier flood that are going to kill you if you are in flood path. In such glacier flood it is not just mud, volcano material, but also an ice bergs that are larger than 5 floor houses. If you get lost in such flood, the chance of being rescued from such flood are none. If you want to watch what is now unfolding do so at the save distance, this show is going to big according to my earliest estimate and guess work (not going to publish that here).

Askja volcano

The dyke from Bárðarbunga volcano has entered Askja volcano. Not the fissure swarm, the volcano it self.
Askja volcano status has been elevated to Yellow.

Bárðarbunga volcano

Cauldrons in Vatnajökull glacier that is on top of Bárðarbunga volcano have not grown during the night.
The water seems to be flowing into Grímsvötn (Grímsfjall volcano) lake. It has risen close to 15 meters in the past few days.
Earthquake activity is high. Both in the main volcano were a magnitude 5,4 earthquake (EMSC magnitude, USGS magnitude) took place today (28-August-2014) at 08:13 UTC. The earthquake took place in the caldera rim as most of the large earthquakes have happened.
Over 1300 earthquakes happened yesterday in the north end of the dyke swarm.
Cracks have started to happen in the crust above the dyke. This means the dyke is getting wider and is higher up in the crust then suggested by earthquake activity. There are reports of small cauldrons in Dyngjujökull glacier in the area, in the place were the glacier is thinnest and ending.
Harmonic tremor remains high on all SIL stations around Bárðarbunga volcano.

The situation is extremely dynamic and is going to change fast in next 24 to 48 hours. I am now close to 80% sure that an eruption is going to take place in both Askja volcano and Bárðarbunga volcano, since minor eruptions have been taking place under the glacier already.

August 28, 2014August 28, 2014

Unclear what is happening in Bárðarbunga volcano

This information is going to get outdated extremely fast.

Earthquake activity remains high.
Cauldron have formed in Vatnajökull glacier just SE and SSE of Bárðarbunga volcano.
The cauldrons are 4 to 6 km long and about 1 km wide.
No harmonic tremor have been seen, but that might have its own reasons.

Earthquake activity in Bárðarbunga volcano for past 48 hours. Copyright of this image belongs to Icelandic Met Office.

Earthquake activity remains dense in Bárðarbunga volcano for the past 48 hours. Copyright of this image belongs to Icelandic Met Office.

Harmonic tremor remains high on Dyngjuháls SIL station. Copyright of this image belongs to Icelandic Met Office.

Harmonic tremor is also high on Kreppuhraun SIL station. Copyright of this image belongs to Icelandic Met Office.

The cauldrons that have been spotted today in Vatnajökull just SE and SSE of Bárðarbunga volcano are in the south end are of the current dyke. What is also important, they are also in an area were magnitude 5,0 earthquake did happen few days ago, in a area that has not had any dyke activity since 16-August-2014 when this all started. It is still unclear what happened to all the water in this melt, the glacier in this area is 400 to 600 meters thick and this is not a little melt that has taken place in the glacier. There is a chance the water did go to Grímsvötns lake (caldera like in Grímsfjall volcano), but that remains unclear at the moment.

I am going to post more information about this once I have them.

Updated at 00:14 UTC on 28-August-2014.

August 27, 2014August 27, 2014

Bárðarbunga volcano update at 00:31 UTC

This information is going to get outdated quickly.

This is the short update on status on the activity in Bárðarbungu volcano.

Current activity is mostly unchanged. Earthquake activity remains high and there are around 1000 earthquakes every 24 hours.
According to the news today and Icelandic Met Office data, the dyke doesn’t appear to be getting longer. It is now around 37 km long.
Largest earthquake since 2008 took place in Bárðarbunga volcano on 26-August-2014 at 01:26 UTC. It had the magnitude of 5,7 and took place in Bárðarbunga caldera. Second medium earthquake took place today at 11:56 UTC and had the magnitude 4,6. It was felt in Akureyri.
There are no signs of magma going to the surface as of writing of this article. I do expect that change quickly.
It is now my view that after the magnitude 5,7 earthquake the risk of an eruption Bárðarbungu caldera has increased from what it was. I don’t know yet if an such eruption is going to take place. I however find it to be the most likely outcome based on current status.

The magnitude 5,7 earthquake that took place on 26-August-2014 is the strong earthquake in Iceland since 2008, when a magnitude 6,3 earthquake happened between Selfoss town and Hveragerði in the South Seismic Zone in Iceland (often just called SISZ). Earthquake activity remains high in the north end of the dyke, with strongest earthquake today having the magnitude 4,6. With many more magnitude 3,0 and stronger earthquakes taking place. There are still over 1000 earthquakes being recorded every 24 hours in area where the dyke is located (about 20 km east of Trölladyngja).

Earthquake activity in Bárðarbunga volcano today. This map is already outdated. Copyright of this image belongs to Icelandic Met Office.

Earthquake activity remains extremely dense in the dyke from Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

Total lack of earthquake at the start of the dyke suggest that the flow of magma is now smooth and it is flowing without any resistance to the north end of dyke. Where the dyke seems to have hit a resistance in the crust that he is not able to break at current time. I don’t know if the earthquakes that have been taking place today are going to change that. But if this resistance in the crust holds there is a chance it there are going to be even large earthquakes that are going to take place at this location. What magnitude is to expect is difficult to know for sure, but the crust in this area is able to make earthquakes above magnitude 5,5, but how far up the scale it goes I do not know.

There has been some deep earthquake activity taking place according to the automatic data, but since it is automatic data it might be wrong. The deepest earthquake that I did see to day took place today had a automatic depth of 29,3 km with quality of 90,10. There is a chance this dyke might get into connection of other deep dyke in this area. This are dykes that form deep in the crust at depth of more then 30 km, they don’t make any earthquakes when they form since the crust material in this region of the crust is soft and is unable to break and does not make an earthquake as result. I do not know what happens if this dyke manages to connect to an dyke that might have formed in the deeper range of the earth crust in this area. It is also a highly unlikely outcome, for the moment however it is not impossible. Since the dyke now has problems pushing north, and as an result of that it seems to be pushing a little bit down as result. It is clear that once it can not extent any future down or to the sides, it is going to go up. I am not expecting the flow of magma into the dyke to drop any time soon. That might happen, it is just unlikely to happen given the current data. Estimated amount of magma is around 350 million m³ today (26-August-2014).

Harmonic tremor remained high in Bárðarbunga volcano due to magma flow in the dyke. This is Dyngjuháls SIL station. Copyright of this image belongs to Icelandic Met Office.

Here is the harmonic tremor in Bárðarbunga on the SIL station in Kreppuhraun. Copyright of this image belongs to Icelandic Met Office.

The harmonic tremor shows that the dyke inflow continues as I did write about above. It also shows one important thing, the flow of magma into the dyke and presumably into Bárðarbunga volcano is not even. It happens in short periods of high inflow with lower periods between them.

GPS data show the magma continues to flow into the dyke at 5 to 10 km depth. More GPS plots can be found here. Copyright of this image belongs to University of Iceland.

The magnitude 5,7 earthquake as it appeared on my geophone in Heklubyggð. This image is released under Creative Commons licence. See CC Licence page for more details.

The magnitude 5,7 earthquake as it appeared on my geophone in Böðvarshólar. This image is released under Creative Commons licence. See CC Licence page for more details.

What this has told me is that there is far more magma in Bárðarbunga volcano then appear at first sight. How much of it can actually erupt in an eruption I do not know. But this seems to be far more complicated then I first thought, it is not just a dyke pushing out of Bárðarbunga volcano. There is also a lot more magma inside the magma chamber that is starting to look for an way out, at least from the looks of current activity. The glacier inside the caldera is 700 meters thick so the magma inside the magma chamber that is directly below the caldera is under this extra pressure from the glacier. Once that magma overcomes the pressure of the glacier an eruption is going to start in the caldera, until that time we might see more dyke activity going north and south of Bárðarbunga volcano. Since the magma is going to go first the easiest way out. How much pressure has to be inside the magma chamber to overcome the pressure of the 700 meter thick glacier inside the caldera I do not know. All I know is that it is a high number on any pressure scale.

As of this writing a new magnitude 5,1 (more on EMSC website here) has taken place in Bárðarbunga volcano caldera. Larger earthquake appear clearly on my geophones that can be viewed here.

August 25, 2014August 27, 2014

Bárðarbunga volcano update at 20:49 UTC

This information is going to get outdated quickly. Minor spelling note. ~~It appears that dike is spelled with a simple “i” not a “y”.~~ Information on what volcano dyke is can be found here on USGS website. Added: That is in U.S English, UK English uses Dyke so I am going to use UK English. Thanks to Squonk to pointing me to this information.

Special note on Askja volcano

There are many people speculating that the dyke might reach into Askja volcano. I find that to be unlikely outcome. That does not appear to have happen in the past and I don’t think the geology setting allows for it. The area is full of old dykes that have cooled into granite type of rock (and other hard types of rock) in the crust (this is a volcano area and I find this to be likely). Given the density and how hard granite is I find it unlikely that this magma is going to break it. It has been crossing softer rock in the crust for the past week. What I can’t rule out is that Bárðarbunga volcano might start an eruption in Askja volcano by some other mechanism that might or might not be well understood. Askja volcano did start to prepare for eruption cycle in the year 2010 (earthquake swarm at 20 km depth was the clue), but the process appears to be slow, at least the volcano doesn’t appear to be ready for an eruption as things look now.

Special note on Tungnafellsjökull volcano

Yesterday (24-August-2014) an magnitude 3,0 earthquake took place in Tungafellsjökull volcano, a small volcano west of Bárðarbunga volcano. There had been few other earthquakes also yesterday, just smaller. Currently there is nothing suggesting that Tungafellsjökull volcano is about to erupt. There has been earthquake activity taking place in Tungafellsjökull volcano during the past year, suggesting that the volcano is experiencing flow of new magma at depth (more then 15 km depth), but there isn’t anything to suggest that an eruption is imminent in it. There is also a good chance that current earthquake activity in Tungafellsjökull volcano is due to stress changes in the crust that are taking place due to the caldera of Bárðarbunga volcano is getting lower (more on that later in this article). I don’t think Bárðarbunga volcano is able to start an eruption in Tungnafellsjökull volcano, but this is also an volcano that has never erupted during historical times and current data suggest it might not have erupted at all during the last 10.000 years (or more). Tungafellsjökull volcano is located west of Bárðarbunga volcano, it has a green star on it currently (as of this writing) on Icelandic Met Office earthquake maps.

Bárðarbunga volcano update

Earthquake activity remains strong in Bárðarbunga volcano. Medium sized (magnitude 5,0 – 5,9) earthquakes (more information here)) have been taking place as the caldera gives away due to outflow of magma from the magma chamber in Bárðarbunga volcano. This appears to be happening due to less inflow of magma from depth (the mantle). The crust in this part of Iceland is up to 46 km thick due the mantle plume beneath it (more information in details here, warning a large pdf file). The lowering of the caldera is creating stress changes in the area. What the end result of that is going to be I don’t know, since the crust is slower to respond, but as more stress is build up in the area this way stronger earthquakes can be expected at later time.

Currently the dyke is now at location that last erupted in the year 1797, it has remained bit unclear if it was Bárðarbunga or Askja that started that eruption. Chemical analyse says the lava is from Bárðarbunga volcano, not Askja volcano. This is according to the news I did hear today. Currently the dike north end is now 20 km east of Trölladyngja. Earthquake activity has been picking up and increasing in that area for the past 24 hours. It however doesn’t appear to be as high as it is on the main area of the dyke (about 20 km ENE of Kistufell, north of Dyngjujökull glacier, just check the earthquake map if you are confused by this).

The earthquake activity for the past 48 hours in Bárðarbunga volcano. Green stars show earthquakes with higher magnitudes then 3,0. Copyright of this image belongs to Icelandic Met Office.

The earthquake activity during the past 48 hours in Bárðarbunga volcano has been dense. Copyright of this image belongs to Icelandic Met Office.

Harmonic tremor remains high on Dyngjuháls SIL station. It goes up and down in accordance with the magma inflow into the dike. Copyright of this image belongs to Icelandic Met Office.

Harmonic tremor is also high on Askja SIL station. Same movement can be seen as on Dyngjuháls SIL station. Copyright of this image belongs to Icelandic Met Office.

GPS data shows that more magma has flowed into the dyke during the past 24 hour. More GPS stations can be found here. Copyright of this image belongs to University of Iceland.

In the news today in Iceland I have seen that there is now some discussion that this dyke might not erupt at all. Since it appears both to be getting deeper in some areas and there are currently no signs of it going upwards. The problem with this is the idea is in my view based on wrong parameters so I don’t agree with it. This dyke is going to erupt in my view, it is just a matter of time now. It might not erupt, that is always a possibility. I just think it is highly unlikely to be the outcome of all of this. This dyke is going to continue making a path for it self until it hits a resistance in the crust it cannot break after that it is going to go up, since its easier path for it, rather then to go down into the crust where its path has more resistance. When that might happen is something that I do not know.

Article updated at 21:03 UTC.
Article updated at 21:26 UTC.
Article updated at 00:13 UTC on 26-August-2014.
Article updated at 10:35 UTC on 26-August-2014.

August 24, 2014August 24, 2014

Short update on Bárðarbunga volcano at 12:07 UTC

This is a short update on Bárðarbunga volcano. Due to the fast change that is now taking place in Bárðarbunga volcano this information is going to get outdated quickly.

Earthquake activity now is extremely dense. With 3 to 5 earthquakes taking place every second (best estimate that I have made).
Earthquakes have increased in magnitude.
General activity appears to have increased in Bárðarbunga volcano. Even if no major eruption has yet taken place.
There is currently no signs of this activity stopping any time soon.
The dyke in Bárðarbunga volcano continues to get longer and wider, it is now over 40 km long (I think). Formation of this dyke has slowed due to more difficult crust in the area he is now in (that means more earthquakes).

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

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

Harmonic tremor is getting off the tremor plot that Icelandic Met Office has on its website. This is the harmonic tremor at 11:33 UTC. This is Dyngjuháls SIL station. It is closest to the dyke at the moment. Copyright of this image belongs to Icelandic Met Office.

The SIL station in Askja volcano is also showing the massive activity in Bárðarbunga volcano. This is the harmonic tremor at 11:33 UTC. Copyright of this image belongs to Icelandic Met Office.

Current length of the dyke from Bárðarbunga volcano. Blue dots are the oldest and the red ones are the newest. This shows the earthquakes from 16-August-2014. Copyright of this image belongs to Icelandic Met Office.

The harmonic tremor seems to increase when there is a new flow of magma at depth into the dyke. Large earthquakes happens in Bárðarbunga caldera when it adjust to this flow out of the magma chamber above it. There are clues that magma at depth might have triggered this, but there is a lack of deep earthquakes in Bárðarbunga volcano so it is difficult to say for sure.

This is the magnitude 5,3 earthquake that took place today (24-August-2014) at 00:09 UTC. This is my geophone in Heklubyggð. This image is released under Creative Commons Licence. Please see CC Licence page for more details.

This is the magnitude 5,3 earthquake that took place today (24-August-2014) at 00:09 UTC. This is my geophone in Böðvarshólar. This image is released under Creative Commons Licence. Please see CC Licence page for more details.

This is the magnitude 5,1 earthquake that took place today (24-August-2014) at 05:33 UTC. I use data from EMSC that explains different magnitude in the image. This is my geophone in Heklubyggð. This image is released under Creative Commons Licence. Please see CC Licence page for more details.

As explained above the earthquake activity is dense under Dyngjujökull at the moment. The dyke is also now in part on glacier free area, so if any minor eruptions happen they can be seen on the surface. The dyke seems to be under high pressure, but I don’t know yet if that is going to result in an eruption. But I find it highly likely at this point and given current data.

My geophones can be seen here. Some of the activity that is now taking place in Bárðarbunga appears on them. Larger earthquakes (magnitude 3,5 and above) appear always at this distance. Wind appears on my geophones if weather is bad in Iceland.

Updated at 14:12 UTC.

August 23, 2014

Smallest of eruptions so far (Bárðarbunga update at 20:43 UTC)

This is a short update and this information might go outdated quickly.

It appears that the eruption that took place in Bárðarbunga volcano was a minor one. It also looks like that the eruption was so small that it didn’t even make dent in the glacier on top of it, but the glacier in this area is around 400 meters thick. Such minor eruptions are not common in Iceland, but they do happen once in a while.

Earthquake activity today (23-August-2014) in Bárðarbunga volcano. Copyright of this image belongs to Icelandic Met Office.

Largest earthquake today had the magnitude of 4,5 (EMSC information here) – 4,7 (USGS). Other earthquakes that have taken place today have been smallers, few earthquakes with magnitude above 3,0 also took place today.

The harmonic tremor that took place in Bárðarbunga volcano today. It makes a clear mark from the other magma movement that has been taking place during the past week. This is Dyngjuháls SIL station. Copyright of this image belongs to Icelandic Met Office.

This harmonic tremor was also visible on Kreppuhraun SIL stations. Copyright of this image belongs to Icelandic Met Office.

GPS data showing current inflation on Dyngjuhjáls. More plots can be found here. Copyright of this image belongs to University of Iceland.

Current GPS data show that inflation to the north has stopped, while inflation to the west has increased and up to 2 to 3 cm a day based on newest GPS data. This means that more magma is flowing into the dyke on 5 to 10 km depth. The dyke continues to extent, but now it is moving more north rather then north-east as before.

The eruption that took place today was a minor one. I am not even sure it lasted a whole hour, but since it was under a 400 meter thick glacier that is only guess work on my end based on tremor data that I have. This might however not be the last eruption in Bárðarbunga volcano, far from it. Short eruptions like this one might happen on regular basis now in Bárðarbunga volcano and not all of them are going to take place under glacier in my view.

August 23, 2014

Minor eruption confirmed in Bárðarbunga volcano

Short update. This information is going to get outdated quickly.

A small eruption has started in Bárðarbunga volcano. So far this is just a minor eruption. So far the eruption is under the glacier.

I am going to post more information when I know more.

August 23, 2014August 23, 2014

Possible eruption in Bárðarbunga volcano

This is early information and it might be wrong! Eruption might not be taking place and this might be a trick of magma movement underground. It is hard to be sure in this case until a visual confirmation is in place.

It appears that an eruption is about to start or has started in Bárðarbunga volcano. The harmonic tremor is going trough the roof at this moment.

Harmonic tremor is going in Dyngjuháls SIL station at 11:09 UTC. Copyright of this image belongs to Icelandic Met Office.

Harmonic tremor is also going up at Kreppuhraun SIL station. Copyright of this image belongs to Icelandic Met Office.

Harmonic tremor is also going up at Mókollar SIL station at 11:10 UTC. Copyright of this image belongs to Icelandic Met Office.

It is unclear what is going on at this moment. Nothing has been confirmed yet when this text is written. This might not be an eruption at this point in time, but that might change without warning at any time.

August 22, 2014August 23, 2014

Bárðarbunga volcano update at 21:11 UTC

This is a short update. I am still a little sick (sigh) so it’s a bit hard for me to work properly.

Information here is going to get outdated quickly and without warning.

Few short points on current activity in Bárðarbunga volcano.

Earthquake activity is high today (22-August-2014). There is less earthquake activity today than was yesterday (21-August-2014).
Dyke formation continues at depth of 5 to 10 km. The push north seems to have stopped or slowed. Currently it is estimated that the dyke is getting wider. There also less resistance in the crust (appears to be), leading to fewer earthquakes taking place. This dyke is now estimated to be 25 km long.
Bárðarbunga caldera appears to have given away due to less magma holding it up. As magma has flowed into the dyke. It is now estimated that 200 million m³ of magma has flowed into the dyke.
Inflation so far is 20 cm according to news on Rúv with information from Icelandic Met Office.
So far around 5000 earthquakes have been recorded since this activity started on 16-August-2014.

There are also signs that this might be a start of a new eruption cycle for Bárðarbunga volcano. Not all events in this cycle are going to lead to an eruption. This is the same pattern as took place in Krafla volcano during it’s eruption cycle [Wikipedia information, University of Iceland information]. It remains to be seen if this idea is true in part or whole.

There is less earthquake activity today then yesterday. Copyright of this image belongs to Icelandic Meteorological Office.

Earthquake activity remains stable, it goes up and down and currently there has been less activity then yesterday (21-August-2014).

Less earthquake activity clearly shows on IMO earthquake graph. Copyright of this image belongs to Icelandic Meteorological Office.

Harmonic tremor remains high even during less earthquake activity. The high harmonic tremor is most likely taking place due to magma inflow under ground. It does not appear to be connected with earthquake activity (for most part). Copyright of this image belongs to Icelandic Meteorological Office.

GPS data clearly shows the inflation that has been taking place in Bárðarbunga volcano. Inflation to the north has slowed down, while inflation to the west continues. More GPS information can be found here. Copyright of this image belongs to University of Iceland.

The magnitude 4,7 earthquake as it appeared on my geophone in Heklubyggð. This image is released under Creative Commons Licence. Please see CC Licence page for more details.

The magnitude 4,7 earthquake as it appeared on my geophone in Böðvarshólar. This image is released under Creative Commons Licence. Please see CC Licence page for more details.

Largest earthquake so far is an magnitude 4,7 earthquake (EMSC information here) that took place yesterday (21-August-2014). A magnitude 4,3 earthquake (EMSC information here) took place today (22-August-2014) at 15:41. This strong earthquakes happened due to the lowering of the caldera as explained above. If the dyke intrusion continues, more earthquakes are going to start happening. It is not known how much magma, if any is coming from depth (mantle depth) at current time with lack of deep earthquakes in all this activity, it is impossible to know if any magma is coming up from the mantle.

News in English

Met Office: 25 km long dike formed (Rúv.is)
Strongest earthquake yet in Bardarbunga (Rúv.is)

Updated at 21:17 UTC.
Updated at 21:19 UTC.
Updated at 21:41 UTC.
Updated at 23:22 UTC.

August 21, 2014

Bárðarbunga caldera possibly lowering

This is a short no-picture update on the status in Bárðarbunga volcano. This information is going to get outdated quickly.

There are now clues that Bárðarbunga volcano caldera is getting lower. While there are no signs of imminent collapse such event might happen since this process has started. This explains the earthquake the activity in the caldera, that has been taking place for the past 48 hours. What this means in terms of an eruption I do not know, what I do know is that this type of event if it happens are never small and the following eruption might be huge. This is also going to change the landscape in Vatnajökull glacier forever (that is common thing in Iceland during an eruption cycles).

There has also formed a 25 km long dyke trench in the crust that goes north-east at the moment. There are clues that it might be getting wider at this moment. It appears to have stopped going north-east for the time being.

More details on this later when I know more (and my health is slightly better).

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