iceland Bárðarbunga and Askja - Volcanic Activity

[Sussex Jules]

I think about 25m jogs but that was earlier has dipped a bit this evening

[john pike]

During 10-16 September, IMO maintained Aviation Colour Code Orange due to continued activity at Bárdarbunga’s Holuhraun eruptive fissure. Lava flows continued to advance at a consistent rate toward the E and W, and by 13 September, the lava field measured 24.5 km2. The main flow had entered the river bed of Jökulsá á Fjöllum and continued to follow its course; steam rose from the river where the lava was in contact but no explosive activity occurred. Persistent subsidence was detected from the Bárðarbunga caldera; approximately 23 m of total subsidence was measured during a survey on 14 September.

 

http://volcano.si.edu/volcano.cfm?vn=373030

 

add about 2m since the 14th = about 25+- 1

[john pike]

http://hraun.vedur.is/ja/Bardarb/BARC/

 

dropping again

 

im off to bed

 

goodnight all

[john pike]

18 September 2014 - gas emission rates

Measurements of SO₂ emission rates with permanently installed scanning DOAS instruments preliminarily indicate 200-600 kg/s SO₂ over the last week of the eruption.

Relating SO₂ to other gases measured by FTIR preliminarily indicates 250-700 kg/s CO₂, 2-6 kg/s HCl, 3-8 kg/s HF, and <1 kg/s CO.

These emission rates may be underdetections due to measurement conditions. Experiments will be made this week to help us constrain the measurement bias and uncertainty, and these emission rates will likely change. These values are not to be used for further research as they are preliminary and all rights to the data belong to the scientists who are acquiring and interpreting the data.

The participating institutions include: Icelandic Meteorological Office, Chalmers University of Technology, Istituto Nazionale di Geofisica e Vulcanologia, Düsseldorf University of Applied Sciences, University of Palermo, University of Cambridge, and British Geological Survey.

 

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

 

i found that interesting

 

now i am gone

 

nite

[NorthNorfolkWeather]

Much quieter since midnight, Nothing over M2.

 

Seems to have a cycle of agitation, a big quake then quiet until the next run.

 

I think that JP's concerns about the North East flank are well founded, but, as Jon FR has said on numerous occasions, we are in unexplored (or at least previously unmeasured) territory.  Even from here it could just settle down and go back to sleep, but with the number of quakes over M4 in the caldera, this has to be the least likely scenario to happen.  Much more likely is an eruption in the caldera, if that happens we need to look at the lava type to determine to overall effect, basaltic flood lava will produce a lot of gas, but not much in the way of explosive activity, rheolite on the other hand may produce a lot of explosive activity and ash.

[karyo]

Much quieter since midnight, Nothing over M2.

 

Seems to have a cycle of agitation, a big quake then quiet until the next run.

 

I think that JP's concerns about the North East flank are well founded, but, as Jon FR has said on numerous occasions, we are in unexplored (or at least previously unmeasured) territory.  Even from here it could just settle down and go back to sleep, but with the number of quakes over M4 in the caldera, this has to be the least likely scenario to happen.  Much more likely is an eruption in the caldera, if that happens we need to look at the lava type to determine to overall effect, basaltic flood lava will produce a lot of gas, but not much in the way of explosive activity, rheolite on the other hand may produce a lot of explosive activity and ash.

That's how it tends to look first thing in the morning because there are no (or not enough) staff at IMO overnight to measure the earthquakes. The IMO has now updated and there was a 3.8 at about 2am and a 3.2 a couple of hours ago.

 

Let's see what today brings.

[karyo]

M4.6 in the last hour!!!

 

Karyo

[NorthNorfolkWeather]

This looks quite a bit further north than most

 

Friday
19.09.2014 04:52:31 64.736 -17.509 8.0 km 3.2 99.0 10.6 km N of Bárðarbunga

 

 

Still in the 6-8km depth area

Edited September 19, 2014 by NorthNorfolkWeather

[karyo]

Three quakes over M3 since 6am!

[BrickFielder]

 Following on from yesterdays musings I thought I would explain a premise that perhaps subsidence at Bárðarbunga preceded the eruption or more specifically a little injection of magma could cause subsidence which caused the eruption.

 

A potential model of the magma chamber.

 

 

A little injection of magma lubricates a solidified block of magma in the chamber and it begins to slip down.

 

The solidified block acts as a plunger on the magma forcing it out along a wider ring fault into a fissure.

 

The solidified block slips further trying to pull down the caldera roof. Water seeps into the area above the solidified magma causing little steam eruptions which bump the caldera floor. The caldera floor begins to slip on its ring faults and reverse faulting cracks open up.

 

Or on the other hand the magma chamber could be more like an hourglass shape as explained in the following paper.

 

http://rses.anu.edu.au/~hrvoje/Tkalcic_etal_BSSA2009.pdf

 

 

 

[swebby]

Afternoon - has anyone got links to working drum plots?  The ones I have effectively stopped early hours yesterday, not sure if it is bad links or that the data is not being put online from source?

 

Tremor plots looking quiet, bar the start of a possible increase on askja.

[swebby]

Update out from the IMO - http://en.vedur.is/media/jar/Factsheet_Bardarbunga_20140919.pdf

 

Interested about the analysis of lava indicating a source depth >10km and the plot of EQ's over the past month.  <10km for the caldera and initial intrusion but now > 10km for the fissure/dike.

 

I suppose the caldera piston hypothesis fits this but I do wonder if the fissure is being fed directly, either from below or from a source below the caldera.  If the lava was sourced directly from the magma chamber I would have thought it would have characteristics of shallow and/or evolved magma?

[BrickFielder]

Pick up in tremor at skrokkalda(skr)

 

http://hraun.vedur.is/ja/oroi/skr.gif

 

Looks like possible magma movement  with nearest volcanoes Harmarinn or Tungnafellsjökull.

 

Not showing up clearly on the vonaskard SIL so possibly more likely Harmarinn.

 

Could also be SIL mal function or weather ?

[swebby]

Winds are meant to light today so weather should not be a big issue with them at the mo.

[karyo]

4.3 in the last hour but no drop in the GPS.

[karyo]

At long last the fog has cleared! The fissure is still going but the main difference is the increased amount of steam coming from the river.

[If Wishes made Weather]

It looks like quite a lot of the tremor plots have been rising a bit this afternoon, and another 4+ as Kayro notices (although 3dBulge are not showing it on their system).  That seems to be 48hrs of these 3+ quakes at regular intervals in the caldera. Clearly something has changed a bit.

[Rustynailer]

Everything I can get in 5 mins break...Hope it helps with visualizing events...

 

Detail.... 

 

L8r's.

 

Carls theory is good but a weakness has been identified, the hydraulic pressure is directed under the glacier, allowing the hovercraft effect on a very large down hill facing cracked glacial chunk....

 

 

Skiing in the snow,  is a Northern Soul record , that may not go down too well  for some....

 

NE quad flank collapse, still my preferred option, nothing changed.

Edited September 19, 2014 by Rustynailer

[john pike]

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

 

can see now :)

[karyo]

Another M3.5 in the last hour.

 

http://en.vedur.is/earthquakes-and-volcanism/earthquakes/

[john pike]

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

 

that looks quite lively now

 

and also a new fissure opening near the station???

[Rustynailer]

Another M3.5 in the last hour.

 

http://en.vedur.is/earthquakes-and-volcanism/earthquakes/

There appears a change in the reaction Vs:- lava/water the lava is glowing up at the point of maximum interaction, lava composition,  chemical changes. perhaps. its only a thought.

 

Worthy of the National gallery, stuff....   

Edited September 19, 2014 by Rustynailer

[Allseasons-Si]

Nice to see the eruption again after so much dross,she looks beautifull tonight(need a capture)lol

 

also,looks like there is someone down there,i envy them,someone in the air too.

 

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

Edited September 19, 2014 by Allseasons-si

[john pike]

 

and up this goes again

[john pike]

Friday

19.09.2014 21:05:30 64.614 -17.449 0.1 km 2.0 99.0 4.7 km SE of Bárðarbunga

 

interesting depth

 

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