iceland Bárðarbunga and Askja - Volcanic Activity

[john pike]

hi as

 

only what i have read so wouldnt bet my house on it

 

although the mo reports seem to say alls the same

 

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

[john pike]

http://en.vedur.is/weather/forecasts/areas/

 

viewing may be tricky before saturday if these are correct :-(

[karyo]

Barda has gone quiet again! So far, it doesn't look like a repeat of last night .

[frogesque]

Is she regrouping - a calm before the storm or simply bored with it all and gone back to sleep?

[john pike]

 

this looks to be heading up again

 

to me quiet is not golden with this

 

going to bed now

 

now watch a big quake hit soon

 

nite all

[john pike]

Wednesday

17.09.2014 22:28:29 64.621 -17.459 7.1 km 3.2 99.0 3.9 km ESE of Bárðarbunga

 

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

[john pike]

Wednesday
17.09.2014 22:52:08 64.683 -17.464 6.9 km 4.1 99.0 5.6 km NNE of Bárðarbunga

 

 

nite all

Edited September 17, 2014 by john pike

[The PIT]

No quakes up 5 after last one a four but it#s still trembling away. Nothing on cams once again.

[NorthNorfolkWeather]

Nothing large since just before midnight, cameras still not working.  What's happening  --  no idea

 

 

Reminds me of that Kitkat ad from a few years back.

 

 

 

 

Been updated now with a 4.5 just after 03:00

Edited September 18, 2014 by NorthNorfolkWeather

[karyo]

 

 

 

 

Been updated now with a 4.5 just after 03:00

Indeed! And also a 3.5 at about 6am

[NorthNorfolkWeather]

And now there's this one

 

Date Time Latitude Longitude Depth Magnitude Quality Location Thursday
18.09.2014 06:05:17 64.669 -17.389 0.3 km 3.4 99.0

7.3 km ENE of Bárðarbunga

 

 

Note the depth only 0.3km  --  shallowest I've noticed here.  Possibly ice fracturing and falling either into water or a void?

[Freddie123]

Larger earthquakes so far today:

 

18.09.2014 10:46:36 64.670 -17.409 8.8 km 3.8 99.0 6.5 km ENE of Bárðarbunga

18.09.2014 06:05:17 64.669 -17.389 0.3 km 3.4 99.0 7.3 km ENE of Bárðarbunga

18.09.2014 03:17:08 64.673 -17.406 6.4 km 4.5 99.0 6.8 km ENE of Bárðarbunga

Edited September 18, 2014 by Freddie123

[karyo]

There was a M5.1 in the caldera in the last hour accompanied by a drop in the GPS!

Karyo

[Allseasons-Si]

There was a M5.1 in the caldera in the last hour accompanied by a drop in the GPS!

Karyo

You bet me to it lol

 

@1.8km too

 

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

 

that's some drop.

Edited September 18, 2014 by Allseasons-si

[karyo]

You bet me to it lol

 

@1.8km too

 

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

 

that's some drop.

Jon Frimann said earlier that today's seismicity in the caldera is worrying and he will update us later.

[Yarmy]

I suppose Askja should be dropped from the thread title now. 

 

(Now watch as the intrusion heads straight for her).

[BrickFielder]

  Plenty of Earthquakes at Bárðarbunga caldera today and another meter drop acording to the GPS with a smattering to the north west of the caldera which seems new.  One or two earthquakes under the eruption site as well but not as proflici earthquakes wise as earlier in the month.

 

Latest notes from the meeting of the Scientific Advisory Board took a slightly different tone today.

 

 

Seismic activity

....  Seismic activity has been rather intensive. ....

..... magma movement under Bardarbunga is changing .....

http://en.vedur.is/media/jar/Factsheet_Bardarbunga_20140918.pdf

 

The options are now.

Eruption declines or large scale subsidence of the caldera occurs with or without a major eruption.

 

This suggests to me a deep level of concern about the caldera collapse.

 

Ok so thats the update over and now I will go off into my own wacky little world of theories (madness).

 

I have been wondering whether the Bárðarbunga magma chamber may have similarities to the Skaergaard intrusion based on the gravity anomalies (higher densities under Bárðarbunga which may be linked to gabbro). I thinking that there may be hardened magma along the walls celining and through part of the magma chamber. The Skaergaard intrusion is thought to have developed under Greenland when the mantle plume currently under Iceland was under Greenland. It is also thought that a narrow sill fed the magma chamber from the top.

  Reading the following paper though I would really have to question this idea. The paper also poses a number of other questions. For example for the mixing of old and new magma which is suggested there has to be a quick (possibly less than a year) an significant injection of new magma into the magma chamber for the magmas to mix properply.

http://petrology.oxfordjournals.org/content/early/2012/09/27/petrology.egs061.full

 

 

 

Somewhere I read that at spreading plates magma chambers should be like upturned boat hulls in shape. Equally depending on the rate of spread the magma chambers should be more pear shaped.

 

Or combing the two  (you would expect earthquakes away from the caldera if this was true)

 

Now we know there is some sort of magnetic anomaly in Bárðarbunga suggesting dense rock or solidifed magma so perhaps the top of the magma chamber looks like this.

 

 

Which makes me wonder whether the caldera sits on base rock or solidifed magma and if there was a layer of solidifed magma in the chamber what was above it, upto the magma chamber ceiling.

 

As ever I am probably talking rubbish, but one explantion for earthquakes being all the way down to 10km (providing the magma chamber is not down below 10km) is that solidifed magma in the chamber is breaking up some how. Perhaps even subsidence and rifting preceeds eruptions?

 

Perhaps I better leave it to the experts to muse on these things.

 

Oh here is a very easy to read document about the atlantic plates covering iceland as well.

 

http://www.southampton.ac.uk/~jtc/fierydeep.html

Edited September 18, 2014 by BrickFielder

[john pike]

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

 

about half a metre drop today and certainly after the 5.3 quake

 

 

 

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

 

still looks as we were

 

shame no cams yet

[If Wishes made Weather]

It looks like we may be in for a big night with multiple shocks in the Bárðarbunga caldera since this morning.  I'm not sure Brickfielder that your thoughts are musings are so mad.  There is clearly something around the 6 to 8 km depth that is causing the unquiet there and although I wouldn't know what it is, it would appear that it isnt particularly fluid as I would have thought that a sort of uniform fluidity in the magma would a) show few or no quakes owing to less friction, and b) such quakes as occur would be more randomly spread?

[karyo]

Bardarbunga is indeed looking agitated this evening! A lot of activity in the caldera.

[john pike]

Holuhraun Lava Could Fill All Buildings in Iceland By Eygló Svala Arnarsdóttir September 18, 2014 13:58

The lava in Holuhraun. Photo: Bernard Meric.

Volcanologist Ãrmann Höskuldsson estimates that 200-250 million cubic meters (7.1-8.8 billion cubic feet) of lava have been emitted by the Holuhraun eruption. For comparison, according to the National Registry, the combined space of all buildings in Iceland is 148 million cubic meters.  

The size of the lava flow is now estimated to be 25-30 square km (9.7-11.6 square miles), which makes it one of the largest eruptions in Iceland since the 19th century.

The lava flow from Kröflueldar, a series of eruptions in Krafla from 1975 to 1984 was 60 square km and the estimated volume of the lava was 250 million cubic meters. But square kilometers only tell half the story, visir.is reports.

Geophysicist Ari Trausti Guðmundsson explained that the volume of the new lava field is, on one hand, based on carefully calculated square meters, and then the estimated thickness of the lava. The cubic volume is when those two numbers are multiplied together.

“For comparison I can name that the Heimaey eruption in 1973 reaches 200 million cubic meters. It’s very thick but it’s only 3.4 square km,†said Ari Trausti.

 

http://icelandreview.com/news/2014/09/18/holuhraun-lava-could-fill-all-buildings-iceland

[john pike]

Updated information 18 September 2014 18:50 - from geoscientist on duty

Nearly 150 earthquakes have been recorded since midnight. About 45 of them occurred in Bárðarbunga, the largest a magnitude 5.3 at the northern rim of Bárðarbunga caldera at 14:22. The GPS station on Bárðarbunga showed a drop of 15 - 20 cm at the time of the earthquake. Two earthquakes occurred with magnitudes between 4 and 5 and four of magnitudes between 3 and 4. Over 50 earthquakes were recorded along the northern part of the dyke, all within magnitude 2. About 30  earthquakes were recorded by Herðubreið and Herðubreiðartögl, all with magnitudes below 2

 

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

[Rustynailer]

First time I have seen the fissure today   So it has not stopped yet, the danger for Bada is when the fissure stops I think.

The back pressure , like EJ in 2010.

[Allseasons-Si]

@ Rusty,ooooh!!! well spotted,now i can chillax lol

 

is that from the KVERKFJÖLL cam,looks familiar(sorry for the bold,was copied&pasted)

[john pike]

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

 

can just see the flashy thing placed there

 

best time looks sat and sun before 12

 

then tues

 

http://en.vedur.is/

Edited September 18, 2014 by john pike