iceland Bárðarbunga and Askja - Volcanic Activity

[Rustynailer]

I can see them on the drum plots clear enough but for some reason they are not registered on the IMO site so not sure of their location.

The system is busy with other calculations, but they are there alright, they will appear on the main chart today, when someone is allowed to spend the time fixing it, I suspect...

[swebby]

Hmmm

 

Whilst it looks like a fantastic job being a scientist watching a volcanic eruption I would not fancy this one bit

 

https://twitter.com/gislio/status/508921188895428608

 

Even without the worry of volcanic and seismic activity, a 15m drop in glacier height would surely mean crevasses etc.  I know they will undoubtedly be well trained mountaineers  but the idea of jumping out of a helicopter on to a potentially unstable ice field does not appeal.

[Rustynailer]

Hmmm

 

Whilst it looks like a fantastic job being a scientist watching a volcanic eruption I would not fancy this one bit

 

https://twitter.com/gislio/status/508921188895428608

 

Even without the worry of volcanic and seismic activity, a 15m drop in glacier height would surely mean crevasses etc.  I know they will undoubtedly be well trained mountaineers  but the idea of jumping out of a helicopter on to a potentially unstable ice field does not appeal.

If the caldera fails the gps could give a few hours warning possibly.

In the likes of a VE4 through to 6, this will save lives and allow the demolition of embankments saving bridges and other infrastructure from the dreaded glacial flood water.

Obviously if there is a phreatic explosion before collapse, the GPS equipment will just become ejecta...

 

I think the GPS helicopter bit is rather like Thunderbirds, I hope they get away with it, mind I am sure it would take more than a helicopter to set the collapse off, a mag 6 would be needed most likely...maybe.

 

Another Mag4+ at around 11:40 Iceland time. Something at Katla too, but only ice quake or a small EQ I think, about 11:40 IT aswell.

Edited September 8, 2014 by Rustynailer

[karyo]

Ok, IMO has now upgraded one of the earlier earthquakes :-)

[Rustynailer]

Ok, IMO has now upgraded one of the earlier earthquakes :-)

08.09.2014 07:20:04 64,618 -17,396 4,7 km 4,7 99,0 6,8 km ASA af Bárðarbungu

Two on the drumplot    The quake I mentioned "about 11:40" is there but only small as it is somewhere else, I can not find it...

[karyo]

08.09.2014

07:20:04

64,618

-17,396

4,7 km

4,7

99,0

6,8 km ASA af Bárðarbungu

Two on the drumplot   K46.JPG The quake I mentioned "about 11:40" is there but only small as it is somewhere else, I can not find it...

that's better, I was feeling disappointed this morning.

[Rustynailer]

that's better, I was feeling disappointed this morning.

Well perhaps in that case, you may be interested to know that the quake I could not find was likely in the ice above Bada, It looked like a 4+ but it will not be possible to get an accurate figure I think.

 

It is at 11:38 here  Note not accurate yet it has not even been auto corrected to 90%

[karyo]

Well perhaps in that case, you may be interested to know that the quake I could not find was likely in the ice above Bada, It looked like a 4+ but it will not be possible to get an accurate figure I think.

 

It is at 11:38 here K47.JPG Note not accurate yet it has not even been auto corrected to 90%

Thanks for the info, hopefully this will show in the IMO site soon.

 

Karyo

[BrickFielder]

  Anyone picked up on the following two earthquakes in Iceland

 

08.09.2014 05:52:09 Depth 0.0 km Magnitude 1.8    Location 6.2 km ENE of Goðabunga
08.09.2014 05:51:19 Depth 0.0 km Magnitude 2.4    Location 6.6 km ENE of Goðabunga
 

That looks like very shallow earthquakes near to Katla ?

 

The sinking of the caldera under Bárðarbunga looks a bit more complicated than a straight sinking of the caldera (Something I think y Jón Frímann could be hinting at).

 

This does not look like a uniform sinking of the caldera, but suggests to me some elasticity in the caldera floor. That could be due to some form of faulting or perhaps even extra heating from below. Either way I would be surprised if some ice melt is not on its way downwards from the caldera to the magma chamber.

 

I am also looking at the GPS plots for GFUM AND GSIG which I think are near to the volcanoes Grímsvötn and Kverkfjöll.

 

These could be rising due to the fissure intrusion, but could also perhaps suggest some sort of deep seated magma refilling below the whole area. Looking at the VONC GPS plots it is not evident that Bárðarbunga is dropping or at least the closely surrounding area to the caldera.

 

It looks to me like GPS is telling a story.

 

Looking at DYNC and GSIG you can see the fissure opening up as the two areas are pulled apart.

Looking at VONC HAFS and GFUM you can see them all moving toward Bárðarbunga which suggest to me a inflation of the magma chamber at Bárðarbunga before the eruption.

 

As the eruption happens you notice that the VONC GPS goes the opposite way which suggests to me deflation of the Bárðarbunga magma chamber.

 

Todays GPS looks to me like the fissure has stopped opening up and there is either a slight rebound or a slight inflation of Bárðarbunga.

 

Earthquakes at Bárðarbunga today suggest shallow micro quakes in the caldera floor with the occasional deeper strong earthquake. It definately looks like something is going on with the caldera floor to me along with either deeper ring faulting or the feeding dykes into Bárðarbunga.

 

There are some unexplained anomalies which I dont understand like the Grímsvötn lake begining to fill, is this melt from around Bárðarbunga or seperate heating. The cratering along the fissure does this mean there might have been an under ground glacial melt cavern along the fissure with that glacial cavern having now colapsed. What were the crater pits in the glacier near to Bárðarbunga and does this imply the magma was close to the surface, would this also imply the extrusion from the magma chamber was fairly high up in the magma chamber (this might imply the chamber is depressurizing but not emptying and could be shut off with a caldera lowering). Why did the extrusion not follow the Bárðarbunga fault system initially, it could be an existing anomaly like a cavern or that plate boundaries have twisted so fault lines are at a slightly different angle (possibly due to the earlier kafla eruptions).

 

It makes me think something is brewing or our understanding is limited in what is going on.

 

(Charts are from the Icelandic Meteorological Office or from University of Iceland

http://en.vedur.is/

http://www.earthice.hi.is/ )

Edited September 9, 2014 by BrickFielder

[NorthNorfolkWeather]

As the eruption happens you notice that the VONC GPS goes the opposite way which suggests to me deflation of the Bárðarbunga magma chamber.

bbgpseqmap08092014.png

 

Todays GPS looks to me like the fissure has stopped opening up and there is either a slight rebound or a slight inflation of Bárðarbunga.

 

Earthquakes at Bárðarbunga today suggest shallow micro quakes in the caldera floor with the occasional deeper strong earthquake. It definately looks like something is going on with the caldera floor to me along with either deeper ring faulting or the feeding dykes into Bárðarbunga.

 

There are some unexplained anomalies which I dont understand like the Grímsvötn lake begining to fill, is this melt from around Bárðarbunga or seperate heating. The cratering along the fissure does this mean there might have been an under ground glacial melt cavern along the fissure with that glacial cavern having now colapsed. What were the crater pits in the glacier near to Bárðarbunga and does this imply the magma was close to the surface, would this also imply the extrusion from the magma chamber was fairly high up in the magma chamber (this might imply the chamber is depressurizing but not emptying and could be shut off with a caldera lowering). Why did the extrusion not follow the Bárðarbunga fault system initially, it could be an existing anomaly like a cavern or that plate boundaries have twisted so fault lines are at a slightly different angle (possibly due to the earlier kafla eruptions).

 

It makes me think something is brewing or our understanding is limited in what is going on.

Hi BF,

 

have a look at   https://forum.netweather.tv/topic/81229-b%C3%A1r%C3%B0arbunga-and-askja-volcanic-activity/page-40#entry3034703 a couple of pages ago, found it on Twitter

Edited September 8, 2014 by NorthNorfolkWeather

[BrickFielder]

Think the caldera deformation may have taken one of two methods. Firstly a slip on the ring faults to the North of the caldera.

 

For this to happen I would expect the deformation to be consistent from east to west and I am not sure it looks that way. The seond is for some form of elasticity or faulting in the caldera floor.

 

 

Cold rock would not normally deform by 15 meters over about 8km without cracking which could suggest the caldera floor is becoming more pliable below the surface. Either way I see opportunities for any melt water to slip into cracks. The problem is that under 800 meters of ice there should be that much melt water and the top of the caldera floor with ice on top cannot be warmed that much. Too me it feels much more like multiple faulting in the caldera floor induced by slippage on the ring fault to the north of the caldera.  I am thinking the caldera floor has been weakened by recent activity.

 

I am of course most likely wrong.

[swebby]

Hi BF - good post.

 

I've seen posts on volcano café that express opinions that may be in answer to a couple of points you raised.

 

The filling of the grimsvotn subglacial lake - This I think has been attributed to the very first eruption back in august, 23rd, the one suspected to have occurred over the start of the dike intrusion next to the calderas edge.  The drainage basin for any sub glacial melting in this area is meant to be south towards grimsvotn rather than north towards the edge of the dynjujokull glacier.

 

Shallow quakes @ katla - If not ice quakes then there is also meant to be some hydrothermal activity at katla and/or an unstable old lava intrusion that regularly results in shallow EQ activity. 

 

In both cases the above are snippets of info I've seen posted elsewhere so I would not swear they are the gospel truth of the situation but they may however fill in some of the blanks you were wondering about?

[BrickFielder]

Jón Frímann  opinion on the shallow quakes near katla.

 

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

 

Those cauldrons are created by hydrothermal areas in Katla volcano caldera. They empty them self on regularly during the year. There is no risk of eruption in Katla volcano at the moment.

 

[john pike]

The lava from the eruption at Holuhraun is flowing at a rate of approximately 100 meters per hour. It is estimated that 100 million cubic meters (3.5 billion cubic feet) of lava have flowed from the fissure since the eruption began, now covering 18.6 square km (12 square miles), an area larger than Hafnarfjörðyour, a town outside Reykjavík.

Volcanologist Þorvaldur Þórðarson told ruv.is that judging by the productivity of the volcanic fissure in Holuhraun, he doubts that the lava, which has traveled 14.5 km (9 miles) so far, can travel much further than 20 km.

http://icelandreview.com/news/2014/09/08/new-lava-covers-area-larger-hafnarfjordur

[KyleHenry]

Magnitude 4.4

Region ICELAND

Date time 2014-09-08 14:48:00.2 UTC

Location 64.78 N ; 17.44 W

Depth 2 km

Distances

226 km E of Reykjavík, Iceland / pop: 113,906 / local time: 14:48:00.2 2014-09-08

105 km S of Akureyri / pop: 16,563 / local time: 14:48:00.0 2014-09-08

Depth of EQ if confirmed a big interest

[KyleHenry]

IMO raises it to 4.9 magnitude depth @ 10km

http://en.vedur.is/earthquakes-and-volcanism/earthquakes/vatnajokull/#view=map

Pattern of large EQ's circling the Bardarbunga caldera continues.

In reply to Brickfielder. A formation of a new Caldera in the making between Bardarbunga and Askja. Out with the old in with the new?

Edited September 8, 2014 by KyleHenry

[john pike]

http://www.livefromiceland.is/webcams/bardarbunga-2/

 

on for now and can see too

[Gael_Force]

Comparison radar of the caldera - today first and 5th second.

 

[Rustynailer]

Large couple of EQ's ...

Edited September 8, 2014 by Rustynailer

[john pike]

a surveillance flight over the Bardarbunga volcano this morning revealed continuing subsidence of the 850 metre thick glacial ice which covers the caldera beneath. Strong seismic activity is still detected around the caldera; the last one, a magnitude 5.0 earthquake occurred at 14.47 GMT.

Following a surveillance flight last Friday over the Bardarbunga caldera, when measurements revealed up to 15 meter subsididence in the center of the caldera, another flight was organized this morning.

The results show that the downward movement continues; since Friday the subsidence has increased by 2.5 - 3.0 metres, or 80-90 centimeters per day. "The events in Bardarbunga can only be described as a slow caldera collapse," says statement on the University of Iceland´s Institute of Earth Sciences´ website. The subsidence is the largest one measured in an Icelandic volcano.

These events are belived to occur in relation to the magma flow out of a chamber, thought to be situated beneath the caldera in Bardarbunga, as magma has been flowing to the north, feeding the effusive eruption in Holuhraun which started last week. 

According to a status report issued Saturday, by the Icelandic Civil Protection Agency´s Scientific Advisory Board, the initial measurements from Friday showed dramatic changes on the surface of the glacier above the caldera,  corresponding to a volume change of 0.25 cubic kilometres, or 250 million cubic meters.

 

bjornm@ruv.is

Below, the preliminary result of todays surveillance flight, titled: Bardarbunga - subsidence of glacial surface (University of Iceland/Institute of Earth Sciences. 

 

http://www.ruv.is/frett/continuing-subsidence-in-bardarbunga

[Rustynailer]

The two large quakes just were under the glacier near the fissure... This could well be a dramatic evening folks, JP that caldera File is alarming but expected...

 

Even the fissure at H looks a bit darker.  

 

A link of the camera's, sometimes they keep the feed longer than we can...http://volcams.malinpebbles.com/pubweb/Iceland.htm  it has the borehole strain of Hekla too, very usaful, if that fails then   

 

Edited September 8, 2014 by lorenzo
Fixing hyperlink

[Buckster]

yes I too have a feeling we are on the brink of something rather interesting

[john pike]

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

 

a new vent opening ????? would help if it was dark

 

hi rusty

 

things looking ominous now but have a feeling a few more days maybe to go

 

i am guessing though on that

[lorenzo]

Has anyone got the links for the plume tracking either the IMO one or the NOAA Hy-split air trajectories.?

[Rustynailer]

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

 

a new vent opening ????? would help if it was dark

 

hi rusty

 

things looking ominous now but have a feeling a few more days maybe to go

 

i am guessing though on that

Yes the main event could well take days, the volcano is so big and complex, the build up proper may well have started, if it has a gradual increase in activity is bound to be easily noticeable for us here , we have so many lovely tools to sit here and watch with.

First thing that will happen I think, most likely is an exciting fissure break out under the glacier away from Bada, it is bound to look great, afterall this is Iceland  , lets hope the weather lets us see some of the action...