Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

[Lizw]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

The SACS home page may be useful as well, at least today, 1 September.

http://sacs.aeronomie.be/

 

[mixin]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

The SACS info is mostly beyond my realm of expertise. I did understand this quite well, though from the front page...

On 1 September 2014, the satellite instruments used in SACS started to detect SO2 over Iceland as a result of the on-going fissure eruption at Holuhraun, Bardarbunga system.
Aviation colour code remains orange according to IMO

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Here is another good link; the IMO keeps it updated frequently. It's much easier to grasp how the magma is moving when you see map C.
Screen caps of the current maps:

B?r?arbunga 2014 - recent earthquakes
Continually updated maps

20.8.2014

In this article, the most recent earthquakes at B?r?arbunga are given by maps that are updated more or less continuously. Each earthquake is represented by a circle. The size of the circle indicates the magnitude. The timing is colour coded, see the bar to the right of each map. The first two maps show earthquakes counting hours since midnight but the third one shows earthquakes since the onset of this seismic event (counting days). The date and timing of each map is in the lower right hand corner (yyyymmdd 00:00).







http://en.vedur.is/earthquakes-and-volcanism/articles/nr/2949

 

[Lizw]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

The maps don't show Askja, which surprises me, but it seems to have calmed down in the last 24 hours anyway.

 

[mixin]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

Updated information

3rd September 2014 12:20 - from the Scientific Advisory Board

Scientists from the Icelandic Met Office and the Institute of Earth Sciences and representatives of the Civil Protection in Iceland attend the meetings of the Scientific Advisory Board of the Icelandic Civil Protection.

Conclusions of the Scientific Advisory Board of the Icelandic Civil Protection:
* Earthquake activity continues ? around 160 earthquakes have been recorded since midnight today. Seismicity is occurring mostly beneath the northern edge of Dyngjuj?kull. A magnitude 5.5 earthquake occurred at 03:08 UTC today on the northern side of the B?r?arbunga caldera.

* GPS measurements show that the volume of the dyke intrusion has increased since the beginning of the eruption; this signifies that more magma is entering the dyke than is being erupted.

* Despite no sign of a volume decrease in the dyke, GPS measurements show that the rate of ground deformation has slowed.

* Recent radar images show a 0.5 ? 1 km wide depression that has formed both in front of and beneath Dyngjuj?kull. Signs of the depression extend about 2 km into the ice margin. The increasing thickness of the glacier decreases the visual extent of fracturing associated with the depression, so it is likely that the area extends further beneath Dyngjuj?kull.

* In light of GPS, radar and seismic results, it is possible that the ongoing eruption could progress southward under Dyngjuj?kull. This would lead to immediate flooding hazards on the floodplain in front of Dyngjuj?kull. Consequently, risk assessments for scientists working in the area will be reviewed.

* The volcanic eruption continues on Holuhraun; the main path for lava is to the east-north-east.
At 08:00 UTC today the total area of the lava flow was estimated at 7.2 km2.

* There have been no observations of ash-fall. Ash production is almost negligible.

* Sulphur dioxide continues to be detected near the eruption site. The eruption cloud is drifting to the north-east from the eruption site.

Four scenarios are likely:
* The migration of magma could stop, resulting in a gradual reduction in seismic activity and no further eruptions.
* The dyke could reach the Earth's surface causing another eruption, possibly on a new fissure. Lava flow and (or) explosive activity cannot be excluded.
* The intrusion reaches the surface and another eruption occurs where either the fissure is partly or entirely beneath Dyngjuj?kull. This would most likely produce a flood in J?kuls? ? Fj?llum and perhaps explosive, ash-producing activity.
* An eruption in B?r?arbunga. The eruption could cause an outburst flood and possibly an explosive, ash-producing activity. In the event of a subglacial eruption, it is most likely that flooding would affect J?kuls? ? Fj?llum. However it is not possible to exclude the following flood paths: Skj?lfandaflj?t, Kaldakv?sl, Skaft? and Gr?msv?tn.

* Other scenarios cannot be excluded.
From the Icelandic Met Office:
The Aviation Colour Code for B?r?arbunga remains at ?orange' and the code for Askja at ?yellow'.

3rd September 2014 06:24 - from geoscientist on duty

Seismic activity continued at similar rate as yesterday until 03:09 when M5.5 earthquake was measured in northern part of B?r?arbunga.
After that there was increase in activity both in the area under the northern part of Dyngjuj?kull, south of the current eruption site as well as in Her?ubrei?art?gl.

The biggest earthquake there was around M3.

Automatically detected events at 06AM are around 130.

From webcam it looks like the eruption continues at similar rate. See earthquake maps

http://en.vedur.is/earthquakes-and-volcanism/articles/nr/2947

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Here's a tweet that just came up:

Retweeted by Univ. of Iceland
Almannavarnir ‏@almannavarnir 23m
Increased unrest in the area around the eruption in Holuhraun #Bardarbunga. Scientist and journalist are leaving the area.

 

[gsgs]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

News of Iceland‎ - 1 hour ago
The Aviation Colour Code for Bárðarbunga remains at 'orange' and the code for Askja at 'yellow'

 

[Lizw]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

The eruption has continued, and is perhaps even growing, but it is very nearly dark now, and the wind has backed around to the southwest, blowing almost directly into the two webcams that are best situated to view the scene. So very little is currently visible. The low frequency tremors indicative of volcanic activity continue. So it's mostly a waiting and watching game now.

 

[Lizw]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

The wind is shifting finally, and the extent of the eruption becoming more visible again. It is growing toward the south, toward the lip of the glacier. Here is a screen cap taken just now.

 

[Emily]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

<blockquote class="twitter-tweet" lang="en"><p>Excellent, steady vid of <a href="https://twitter.com/hashtag/Holuhraun?src=hash">#Holuhraun</a> fire fountain (A Hoskuldsson) <a href="http://t.co/tfIDDZgBky">http://t.co/tfIDDZgBky</a>
MT <a href="https://twitter.com/lava_ice">@lava_ice</a> <a href="https://twitter.com/seismo_steve">@seismo_steve</a> <a href="http://t.co/CxrPuq2gLk">pic.twitter.com/CxrPuq2gLk</a></p>— EGU (@EuroGeosciences) <a href="https://twitter.com/EuroGeosciences/status/507214233663070208">September 3, 2014</a></blockquote>
<script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>


http://www.ruv.is/frett/decrease-in-volcanic-tremor-near-holuhraun

Decrease in volcanic tremor near Holuhraun
Fyrst birt: 03.09.2014 22:25, S??ast uppf?rt: 03.09.2014 22:54
Volcanic tremor near the Holuhraun eruption has decreased in the last two hours, according to the Icelandic Met Office. An evacuation was ordered earlier today, after a sharp increase in the tremor, leading to fears that a subglacial eruption was imminent.

According to Martin Hensch, a geophysicist at the IMO, the origin of the tremor is possibly to be found in the bedrock beneath the northern part of Dyngjujokull outlet glacier, or near the margin of the glacier, south of the Holuhraun eruption site. No signs of a subglacial eruption have been found, and one possible explanation of the tremor increase is that groundwater had seeped through deep cracks in the bedrod, towards the magma beneath.

An alert was issued shortly after noon today, when the increased tremor appeared. About 30 people, mostly scientists, quickly evacuated the area around Holuhraun. Flood warning was issued, as a subglacial eruption was considered a real possibility. They have spent the day at a mountain hut near the Askja volcano, at safe distance...

At least one scientist was killed at Mount St Helens and a lot of tourists were caught up in a nightmare because scientists didn't think the volcano was capable of an explosive eruption. There's an excellent museum up there now.

 

[mixin]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

This fantastic video was posted by one of Jon Frimann's followers:

<iframe src="//player.vimeo.com/video/105365343" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe> <p><a href="http://vimeo.com/105365343">Volcano at night - Iceland September 4 2014</a> from <a href="http://vimeo.com/jongustafsson">Jon Gustafsson</a> on <a href="https://vimeo.com">Vimeo</a>.</p>

Here's a screen cap for those who can't watch videos; it was really hard to pick a "best" shot.

 

[Lizw]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

Another screen cap from just a minute ago, not as dramatic as the one above, but it shows the progression of the eruptions. The new eruption (visible to the left of the image) is only about 1 km from the northern edge of the glacier, and another smaller one is beginning to develop even closer to the glacier. When it reaches the glacier, there will be explosions of steam to go along with the smoke and lava fountains. Best estimate is sometime tomorrow.

 

[mixin]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

15 meter subsidence in Bardarbunga caldera

We see no signs of eruptions or geothermal activity in the caldera itself, but this subsidence does however not decrease the likelyhood that something could happen in Bardarbunga," says Gudmundsson. "One theory is that the bottom of the caldera kind of floats on the magma below, and helps to push it out towards the dike intrusion, which is feeding the eruption in Holuhraun."

"We have not measured an event like this before in Iceland," says Gudmunsson. "We probably have to go back to the formation of the ?skjuvatn caldera in Askja, in 1875, when a large explosive eruption occurred there. That event was of course much larger, with subsidence of about 300 meters, but the current one in Bardarbunga is ongoing, and very significant."

full article: http://www.ruv.is/frett/15-meter-subsidence-in-bardarbunga-caldera

Current screen cap:

 

[mixin]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

From RUV:

"Gravely concerned" about Bardarbunga

Increased subsidence in the caldera of Bardarbunga volcano is a cause for grave concern, due to possible large eruption and glacial flood, says Vidir Reynisson, director of the Civil Protection Agency in Iceland. The subsidence is thought to increase the likelyhood of an eruption in Bardarbunga.

An ongoing lava eruption, which started on August 31, is located on a fissure at Holuhraun, an ice-free lava field north of Bardarbunga. Magma has been propagating from underneath the volcano, towards the eruption, causing subsidence and strong earthquakes in the floor of the Bardarbunga caldera.

The subsidence observed since last week is now up to about 20 metres, says Magnus Tumi Gudmundsson, professor of geophysics at the University of Iceland?s Institute of Earth Sciences.

He notes three possible scenarios regarding Bardarbunga. Firstly that the seismic activity, and the Holuhraun eruption, dies down slowly. A second scenario would see the subsidence continue, as well as the Holuhraun eruption, or even another eruption starting nearby.

"But the third scenario is that the subsidence in the floor of the caldera causes an eruption within Bardarbunga. Such an eruption could melt a large volume of glacial ice, and could end up as a powerful explosive eruption, with ashfall," says Dr. Gudmundsson. "The meltwater would perhaps not be released immediately, due to the contour of the caldera, but eventually it would come out as a powerful flood. Obviously, we are worried about this possibility."

This scenario is regarded as very serious, not least because of the potential for a flood, which could cause extensive damage, says the director of the Civil Protection Agency in Iceland, Vidir Reynisson. "We are gravely concerned about this scenario. If we study the history of the Bardarbunga volcano, we see large and powerful eruptions in or near the caldera; we are bound to take this very seriously, especially after the subsidence was observed."

Tomorrow, Reynisson and his colleagues at the Civil Protection Agency will brief the Prime Minister of Iceland, Sigmundur David Gunnlaugsson, on the situation at Bardarbunga. Today, Reynisson met with the National Power Company, (Landsvirkjun), to discuss the potential consequences of a major flood from Bardarbunga threatening hydropower plants to the west of Vatnajokull glacier, which covers the volcano.

"As soon as the subsidence started in Bardarbunga, the National Power Company acted to minimize the risk of damage due to a potential flood," says Reynisson. "Should an eruption occur in Bardarbunga, it would obviously be of vital importance to pinpoint the location of the eruption inside the caldera, so we could predict the direction of a possible flood. Our reaction would then depend on that information." The caldera itself covers about 80 square kilometres, and lies under a 700-800 metre thick ice cap.

bjornm@ruv.is

This story, by the Icelandic National Broadcasting Service (RUV), was updated on 9 September 2014, at 22.00 GMT.

http://www.ruv.is/frett/gravely-concerned-about-bardarbunga

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Jon Frimann does some further explaining:

Update on the activity in B?r?arbunga volcano

* Earthquake activity continues in B?r?arbunga volcano. The largest earthquake since midnight had the magnitude of 5,2 according to Icelandic Met Office.
* Earthquake activity continues in the dyke south of the eruption area. This suggest that the dyke is still expanding in the crust.
* Minor eruptions have taken place south of the main eruption in Holuhraun. Most of this are like the minor eruption that started south of the main eruption, but in glacier free area. Other minor eruptions that have taken place are under the glacier. They have formed small cauldron in the process without making a glacier flood.
* Cauldron in the glacier have been spotted at 2 km inside the glacier (I think this distance is correct. If it is not. I will correct it), 6 km from the edge of the glacier and 10 km from the edge of the glacier. This cauldron are directly above the dyke and as mentioned above are the results of minor eruption taking place under the glacier. One of this cauldron was discovered on Friday. I don?t remember if it was included in the news that day.
* There are no signs of the eruption in Holuhraun is about to end. The lava field is now creating a dam as it goes over the J?kuls? ? Fj?llum glacier river path. This has created minor explosions in the past few hours and in process throwing up minor volcano ash at the same time.
* There is still a lot of gas in the lava coming from the eruption. Making it extremely dangerous to go close to eruption and the lava field. This gas is in so high consternation that geologist working in the field are often at great risk.
* Smell of sulphur (SO2) has now been found in parts of Norway according to the news (in Icelandic, Norwegian, map in the news from Norway). It is far from being on dangerous levels in Norway due to distance travelled.
* The lava field continues to create its own local weather. Small tornadoes can be spotted on the M?la web-camera. There is also a lot of local cloud formations taking place. Sometimes limiting the view to the erupting area.
* There is high risk of new eruption fissures opening up without warning.
* Eruption activity in the main crater now happens in pulses according to latest news. It drops for a while and then goes high up. I think there is a reason for this behaviour.
* It appears that the erupting crater are being closed slowly by there own erupting material. That might explain the pulsing behaviour that is now being observed from it. This also means there is enough pressure in the dyke to continue the eruption for a good while longer (in my view).
* Inflow of magma and outflow of magma appears to be in balance for the time being. That balance might change without warning if something changes in B?r?arbunga volcano.

http://www.jonfr.com/volcano/

 

[mixin]

Re: Iceland - Bar?arbunga: A small lava-eruption has been detected under the Dyngjuj?kull glacier - Airspace reopened - Aug. 29, 2014

Jon Frimann posted his update today; we all hope it doesn't go this way.

The collapse of Bárðarbunga volcano

The collapse of Bárðarbunga volcano has already started. The caldera collapse in Bárðarbunga volcano started on 16-August-2014 and has been going on since then. Here is what I am expecting from the caldera collapse once it reaches its peak.

* There are going to be earthquakes in the range of 5,5 and up to 6,7. Maybe larger if the crust can handle it.
* Glacier flood are going to go south-west and north (Húsavík area) and possibly in other directions. I am expecting damage to hydrothermal plants in the pathway of the floods. How much damage there is going to be depends on the magnitude of the flood and the path it takes.
* I am expecting long periods of no power in parts of Iceland once the flood has passed. I am also expecting lack of communications in large areas of Iceland. This is why Rúv has been telling people to get long-wave radios for the past few days. Usage of mobile network is also going to be unreliable in large parts of Iceland once the collapse starts full force in Bárðarbunga volcano. Due to damage that glacier floods are going to create.
* I am expecting an ash cloud that might go up to 20 km or higher up in the atmosphere. It is however impossible to know for sure what happens until this starts.
* It is difficult to know fore sure how much drop is going to take place, but it can be up to many hundreds of meters.
* I fear that north slope of Bárðarbunga might collapse forward once this starts. Earthquakes in the area give clues about weakness forming there.
* Bárðarbunga volcano is 2009 meters high above the ocean. This means there is a lot of material that is going to blow outwards once the collapse starts full force. This is might be one of largest eruptions in Iceland since it got populated more than one thousands years ago. I am hoping that the picture that I am drawing up is not as bad the reality once this starts. I am also hoping that no loss of life is going to happen. I am hoping for the best in this case, but the clues that I am getting are no good at all.
http://www.jonfr.com/volcano/

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Twitter:
Univ. of Iceland ‏@uni_iceland 5h
For those asking, data from the new GPS monitor in #Bardarbunga is available here http://brunnur.vedur.is/pub/vatnavakt/bardarbunga/

I think this is measuring the subsidence at Bardarbunga. Here's a screen cap; it's updated periodically



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This is a neat link; it's a map of cameras placed around Iceland. Each one has 3+ views and are updated periodically.

http://vegasja.vegagerdin.is/vefmyndavelar/?xmin=572131&ymax=573390&xmax=790261&ymin=418410

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RUV's latest update:

The caldera in Bardarbunga volcano could subside by hundreds of meters, say two of Iceland´s top geophysicists. The caldera has in recent days sunk by at least 20 meters, increasing the likelihood of an eruption there.
...

Gudmundsson and Einarsson point to three possible scenarios regarding Bardarbunga. (see pictures at the link below). Firstly, that the subsidence will stop and the Holuhraun eruption slowly fades out.

Secondly, the subsidence could continue, along with the eruption in Holuhraun. Another eruption could start, possibly under the Dyngjujokull glacier. In this scenario, the eruption(s) could last for a longer time, with lava volume possibly measured in cubic kilometres. Should a subglacial eruption occur, explosive action and glacial floods should be expected. "The possibilty of the fissure propagating towards the southwest (of Bardarbunga), opening either subglacially or outside the margin of the glacier, can not be excluded."

The third scenario is an eruption within the Bardarbunga caldera. In this case, say Gudmundsson and Einarsson, the magma would find a way up through the rock column beneath the caldera, leading to an eruption inside Bardarbunga. "Such an eruption could melt large volumes of ice, causing a powerful glacial flood. Another possibility is that the water would not immediately escape the caldera, because of the previous subsidence. That meltwater would later produce a large flood. When the eruption would reach through the glacial ice above, explosive eruption with ashfall would be expected."
http://www.ruv.is/frett/subsidence-by-hundreds-of-meters-possible

Gloomy:



http://www.livefromiceland.is/webcams/bardarbunga/