Volcano Watch 2014

a reply to: Doodle19815

It's the sun I think. If there is an eruption going on, it's still melting its way through the glacier right now.

a reply to: ketsuko

That is what they were wondering. It wasn't because of the webcams, it was something going on with media reporting an eruption is under way. I guess the glacier had sunk down over the caldera from what I was gathering from the chat.

Is a wait and see moment.

*still waiting*

I guess a lot of things are going over twitter.
I don't do twitter though so have no idea.

a reply to: Darkblade71

on twitter -

Iceland Magazine ‏@IcelandMag 41m
Breaking news! The ice cap above the #Bárðarbunga volcanic system is opening up. Is this an eruption?

Don't need an account to read the updates at this link - twitter.com...árðarbunga

Take the space out between // and the T in twitter to get to the link -
https:// twitter.com/hashtag/bárðarbunga

Love this pic -

An eruption is considered to have begun
A sigkatla (depression in an ice sheet caused by the volcanic melting of the ice underneath it) has formed southeast of Bárðarbungaa and it is considered that an eruption has begin or had happened. This is according to the Met Office. The scientific committee of the public protection services is now having a meeting with the scientists of the Met Office and the Earth Sciences center of the University of Iceland.

m.dailykos.com... ook

a reply to: Doodle19815

Awesome!

Thank you!

From the twitter link you gave me.

The 10-15 m deep cauldrons, 1 km wide, south of the #Bárðarbunga caldera

a reply to: Darkblade71
Is that crack in glacial ice or is it rock with snow on it?

a reply to: BGTM90

I think it is in the glacier.

I was just looking at this site:
m.dailykos.com...

A sigkatla (depression in an ice sheet caused by the volcanic melting of the ice underneath it) has formed southeast of Bárðarbungaa and it is considered that an eruption has begin or had happened.

This is according to the Met Office. The scientific committee of the public protection services is now having a meeting with the scientists of the Met Office and the Earth Sciences center of the University of Iceland. The public protection department of the state police says in an announcement which was sent out now at 11:00 that they still haven't been able to confirm that an eruption has begun, or had begun, in the northwestern side of Vatnajökull.

Two sigkatlar have formed south of Bárðarbunga's caldera, which is not possible to explain in any way other than that magma has melted the glacier, according to information from the Met Office. TF-SIF, a coast guard airplane, flew over Vatnajökull today and saw the sign of two sigkatlar. The coordination center has been activated and scientists are meeting now about the situation,. They saw land subsidence in a crevice which leads to Askja.

I think that is one of the two depressions in the ice sheet in the picture.

Meanwhile, the dike keeps advancing toward Askja, and it's looking bad:

Eruption likely in Askja if the dike reaches there
There is a great likelihood that the dike under Vatnajökull will enter Askja, says Icelandic geology professor in London. If it enters the magma chamber than there will likely be an eruption. Ágúst Guðmundsson, professor of the geosciences department of Royal Holloway College, has among others researched dikes and volcanic activity in Vatnajökull.

"The probability is now that, and I stress as the situation is at present, that there's a big probability that this dike will enter Askja. And given the size of the dike, i it enters the small magma chamber of Askja then there's a large likelihood that it will be at least breakage and probably an eruption." He says that the dike under the glacier has gotten very long, 42 to 43 kilomters, and that the magma which has gone into the dike is at least one to two cubic kilometers (Ed: stop, take a breath...). He was interviewed in Fréttablaðið this morning.

"It's also good to note that most dikes in the world, whether in volcanic systems or outside them, never reach the surface. That is to say in most possible eruptions, eruptions that are thusly in the pipeline they never erupt."

edit on 27-8-2014 by Darkblade71 because: (no reason given)

a reply to: Darkblade71

I thought maybe that was the mentioned crevice, but I honestly don't know for sure.

a reply to: Doodle19815

I am not sure either.

Where ever it is, is sure is a big crack!

a reply to: Darkblade71

Is there any evidence of elevated melt outflow from the glacier? Could the depressions just be from subsidence from caldera collapse or some other feature no longer supported by magma?

a reply to: BGTM90

I honestly don't know. I am getting a crash course in volcanism here.

According to wiki:

A rift zone is a feature of some volcanoes, especially the shield volcanoes of Hawaii, in which a linear series of fissures in the volcanic edifice allows lava to be erupted from the volcano's flank instead of from its summit

en.wikipedia.org...

I know they are calling them rifts, so it would be caused by magma movement away from the volcano.
Kind of makes me think of a gopher tunnel in a cartoon.

From what else I have been reading and catching through comments, a lot of people are concerned about where the water melting from the glacier is going.

What happens in a phreatomagmatic eruption is usually the erupting magma is directly introduced into a body of water — possibly a crater lake, meltwater from snow or ice, seawater — and the very large contrast in heat (sometimes upwards of 1100°C between water and basalt) causes an explosion of both the water and magma. This is called fragmentation, and ash can be produced during these explosions, meaning what could have been a lava flow becomes an explosive eruption. The 2010 eruption at Eyjafjallajökull in Iceland was initially a phreatomagmatic eruption when the explosive phase started — the erupting magma came into contact with the melting icecap on the volcano and gave it extra explosive oomph — and helping Eyjafjallajökull go from being an eruption that only Icelanders and enthusiasts would note to one that brought Europe to a halt

www.wired.com...

But your guess is as good as mine if not better about what is going on. Everything I have read as far as what is going on is that no one really knows at this point, however, tomorrow should be interesting because there was a lot of talk about things changing really quick around there as far as the glacier goes.

M4.5 - 119km S of Akureyri, Iceland 2014-08-27 23:53:46 UTC

Location

64.624°N 17.663°W depth=8.4km (5.2mi)
Nearby Cities

119km (74mi) S of Akureyri, Iceland
211km (131mi) ENE of Reykjavik, Iceland
212km (132mi) ENE of Kopavogur, Iceland
215km (134mi) ENE of Hafnarfjordur, Iceland
617km (383mi) WNW of Torshavn, Faroe Islands

earthquake.usgs.gov...

*rumble*

a reply to: BGTM90

They're saying there isn't yet, but it could take a while for any increased melt flow to show up out from under the glacier depending on which direction it goes.

The beginning of the article states that the authorities have called an urgent meeting.
And then goes on to say this at the end:

MBL reports there is still no confirmation that an eruption is in progress.

The Civil Protection Science Board “is meeting now to consult on the issue.” The news comes on the heels of earlier reports from RÚV of a 4.5 magnitude earthquake near Askja, stating, “Models of the intrusion, based on GPS measurements of land deformation and earthquake resolutions, indicate that about 20 million m³ of magma have entered the intrusion over the last 24 hours; 3-400 million m³ since the beginning of the episode, on Aug. 16.

The intrusion also seems to have caused considerable stress in the bedrock over a large area, including the vicinity of Askja.”

An annoucement on whether or not an eruption is in progress is still pending.

grapevine.is...

Sounds like they will be saying SOMETHING pretty soon.

Read though the last couple pages of the thread and I didm't see this posted so Ill post it. This is regarding the dyke intrusion:

It is hard to compare this intrusion to any other that we have instrumental data on. The main reason is that we have not seen one like this from a mantleplume volcano, nor have we seen something like this from a rift volcano.

It has a little bit of semblance from the Krafla Fires rifting episode. But I think that comparison is just too simple. First of all that was a much thinner intrusion that never reached this deep, so it was never even close to get down to the mantle. And the most obvious thing is that it kept to its own fissure swarm.

This intrusion has now been inside 3 different fissure swarms, and has the potential for more magma output when it breaks to the surface. In a way it is much closer to how the Skaftár Fires (Lakí) looked, but that eruption also seems to have stayed within its own fissure swarm.

Image by Margaret E. Hartley/Thor Thordarson. Upper part shows a closed propagating dyke. The lower shows a rift open down to the mantle. The upper version draws its magma from a central volcano, the lower from the mantle. Upper alternative would give a smaller eruption than the lower.

two possible solutions for the shape. One is a bottom closed intrusion with no mantle contact, and the second is a full Skaftár Fires version with a wedge shaped obloid intrusion open down to the mantle.

I currently think we have the first option, but that it is really close to the mantle and that it sooner or later will turn into option two. If I am right this will most likely lead to an increased risk for a flood basalt event.

The rift is now 45 km long and roughly 17.5 km high. Calculating the width is though a bit more interesting. If we take the east and west dilation between the Dyngjuháls (DYNC) and Kverkfjöll (Gengissig, GSIG) is by now 44.5cm. To get the correct values we have to take to recognize that the GPS-station are a bit far from the rift so the value is larger. Now, if we compare with the apparent dilation on further out stations we can roughly calculate that the true value is around 135cm. That would make the current volume of intruded magma into 1.05km3.

volcanocafe.wordpress.com...

One thing that is confusing to me is they are saying that the fissure and cauldrons are to the south east of Barda. Isn't the dyke intrusion and Askja to the north?

This is getting more interesting by the day. Unless, you live in Iceland, then I'm pretty sure this episode is more nerve- wracking than interesting...

I've been following along here and at volcano cafe, but I have a few questions/thoughts.

I made a put together one of my no-talent graphics to help illustrate. Bear with me.

First, this is a recent image from the IMO site showing all of the reviewed earthquakes.


And here is my map with the larger quakes around Bardarbunga and Askja (green stars), the dike/dyke (orange squiggle), the "cauldrons"/depressions in the ice (pink circles), and the crack in the old lava field (purple curve* it should be a bit to the NE, off the glacier--I messed that up).
The locations I drew in should be close, but definitely not GPS accurate.


As you can make out, all of the largest quakes have been near Bardarbunga. And what do the pros always say? The little quakes aren't really worth watching. Magnitude 1 and 2 quakes are just centimeter scale adjustments.

Now with this line of depressions in the 650+ meter deep ice, it really does look as if those high mag 4 & low mag 5 quakes initiated an eruption at Bardarbunga, days ago. Maybe a small ooze of basalt magma out of the SE flank of the beast?
I imagine it could take days to cause surface sags in such a deep ice cap, even with 700° -1300°C magma at the base.
Basalt isn't nearly as gas-rich or explosive as more evolved magmas, such as rhyolite, so it could just run out, like at Kilauea.

Of course, there is also this whole dike racing toward Askja--I've no clue what to expect going forward there.

Does anyone know if all of the SIL network seismos are mounted in rock? Are some in ice?
Most all of the signals have looked tectonic to my amatuer eyes. I haven't noticed any that look like ice-quakes, similar to what we saw at Rainier during Winter 2012/13.
Link to Icelandic drumplots

One of the last blurbs from a geophysist in Iceland was that they may have had the earthquake depths calculated too deep under the dyke. This was said in relation to the expanding crack found at the north end of the glacier, in an old lava field. I'll find the link. Would make a fissure eruption much more likely if the earthquakes were actually kms closer to the surface.

I've been following this situation loosely, and what concerns me is WHERE is all the glacier melt water going, if there are depressions forming in the ice (from magma melting the ice below it)? I mean that water has to go somewhere?

It leads me to believe that it may be turning to steam from below, but since we don't seem to be seeing steam coming from any of the cracks in the pictures, it may have not found an outlet yet. After all, that ice is some 700 feet thick or more!

And that is potentially a wicked brew. All that steam trapped below the rest of the thick ice is building up some serious pressure- unless they find where the water has gone... Yes, this could go boom. Big boom.

m.dailykos.com...
I don't get that glacier crack, the map is a bit vague as to where it is, but from my observation this is the spot where the quakes started at, right back on the 16th. The swarm of quakes has moved 45km north east since, it just doesn't make sense.

right click, "view image" for larger versions

a reply to: TrueAmerican

The big mystery is where the water might flow. A huge flood in Jökulsá á Fjöllum glacial river has been feared, but there is no indication that the water level has increased there. Another possibility is that the water has flooded into Grímsvötn, glacial lakes, but then the icecap by the lakes should have risen. Measurements are not available on that yet.

Should melt water have flowed into Grímsvötn it would be collected there before a flood would start to the southwest of Vatnajökull glacier. This happened in the river Gjálp in 1996 when a bridge was swept away, hence closing the Iceland Ring Road.

Víðir Reynisson, director of the Civil Protection Department, told RÚV that the calderas are located further to the south than expected. Hence, it is difficult to predict where a possible flood would occur, to the north or south of Vatnajökull.

icelandreview.com...

www.livefromiceland.is...

Webcam link. It is a beautiful clear picture right now.