iceland Bárðarbunga and Askja - Volcanic Activity

[john pike]

M 4.6 - ICELAND - 2014-10-20 01:00:26 UTC

 

http://www.emsc-csem.org/Earthquake/earthquake.php?id=404956

 

graph shows either 1 long quake

 

or 2 quick quakes together

 

the 01.00 quake on the met office site shows  it 9.0 km ENE of Kistufell

 

that would be a big quake for there

 

have to wait to see what the update shows tomorrow now

 

Edited October 20, 2014 by john pike

[john pike]

[jonboy]

Monday

20.10.2014 08:54:37 64.686 -17.462 4.2 km 5.0 99.0 6.0 km NNE of Bárðarbunga

Monday

20.10.2014 01:00:23 64.612 -17.431 8.3 km 4.8 99.0 5.6 km SE of Bárðarbunga

Monday

20.10.2014 00:38:21 64.619 -17.398 9.3 km 4.2 99.0 6.6 km ESE of Bárðarbunga

On going drop and bounce back ongoing on the vertical displacement graph

http://en.vedur.is/earthquakes-and-volcanism/gps-measurements/bardarbunga/caldera/

Could be another large one on its way

[john pike]

??????????

 

Edited October 20, 2014 by john pike

[john pike]

 

looking like another largish quake incoming

[BrickFielder]

 The facts

It is now the largest eruption in Iceland since the eruption in Laki (Skaftáreldar) in 1783 – 1784 eruption. The eruption at Holuhraun continues as does the subsidence at Bárðarbunga caldera.The lava field (60 square kilometers) continues to grow. The subsidence of the caldera is 35 m and continues at the rate of 30-40 cm/day, mainly in the NE part. The volume of the subsidence is 0.75 square kilometers. Seismic activity in Bárðarbunga continues but with less large earthquakes.

Over the weekend there appears to have been a period of earthquake activity on the south western part of the caldera rim although that appears to have stopped.There also appears to have been some activity just outside the caldera rim to the north east including a 5.2 magnitude earthquake on Sunday  at 03:22 at a depth of 0.1km. Deeper earthquakes at around 5.5 to 7.5 km deep seem to be a trigger for more subsidence although these seem to have reduced somewhat (subsidence rate does not appear to have slowed much though). The scientists dont seem to be able to keep up with verifying the number of smaller earthquakes, which might well reflect that they cannot keep up with the work load over a long period or that they have more important analysis to do.

The speculation bit.

There has been some speculation that the uneven subsidence of the caldera over short time periods (Hours) may be due to an interaction with melted water and lava causing little steam explosions or even that there has been a minor eruption in the caldera. I remain to be convinced off either scenario. It appears to me that the subsidence is a little more uneven over night which could be the effect of melted water re-freezing in newly developed cracks.

 

 

Chart is from the Icelandic Met Office web site here

 

http://en.vedur.is/earthquakes-and-volcanism/gps-measurements/bardarbunga/caldera

 

 

As to why we are seeing earthquakes outside the caldera wall at shallow depths then I think the northern part of the caldera wall is starting to become unstable (could slump inwards if the ice does not hold it up) (starting because I think you need another couple of months of subsidence before it really becomes a problem).

 

From the Icelandic Met Office Website

 

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

 

There is no news on the caldron development near the caldera but there did appear to be some earthquakes over the weekend between Bárðarbunga caldera Tungafellsjökull. The eruption covering has expanded but does not appear to impacted the river that much at the moment with the icelandic met officeshowing a new map of the coverage obtained with a fly over by the coast guard (perhaps we might get to see some updated radar images once they are processed or some news on the caldrons).

http://en.vedur.is/media/jar/myndsafn/full/Yfirlitskort_20141019.jpg

 Over the last week there has been a little swarm of activity at Tungafellsjökull volcano which is just to the north west of Bárðarbunga and there has been speculation that it is at risk of eruption. The Authorities in Iceland dont seem to be that keen on an eruption happening based on the new risk and danger areas mapped out.

http://en.vedur.is/hydrology/articles/nr/2963

 That reluctance to see the potential at Tungafellsjökull volcano might be due to the fact that the volcano has not been active in thousands of years. This I think means that magma within its chamber might well have partially solidified. I also have a suspicion that the rifting event may have increased compression in Tungafellsjökull volcano. This does not mean the swarm is not extremely concerning, just that I suspect the scientist are taking a number of factors into account which we might not know about.

    (Blue lines are meant to represent crustal movement around the fissure)


An unconfirmed twitter report from the university of iceland field team suggests that there has been more degassing at the Holuraun vent site compared to previous weeks. I cannot locate a sensible explanation for this, but my guess would be that the magma being erupted has had less chance to degas elsewhere in the plumbing. I think degassing occurs when pressure on magma drops which would suggest it no longer passes through a lower pressure zone on its way to the surface. This could mean the feed for the vent is now mainly from a deep source or that the pressure in Bárðarbungas magma chamber is no longer low enough for degassing to happen there. This is all speculation off course on a unconfirmed report.

The Icelandic Red Cross had an emergency exercise opening 48 emergency shelters on Sunday the 19th. In addition there are reports of a meeting in Reykjavík  over the weekend for the volcanic hazards group. This seems to have unnerved a few people in the blogosphere that they know more than they are telling, but I suspect a period of relative calm is being used to pool knowledge, ideas and check preparedness.

Other discussions in the blogosphere have contemplated whether the volume of lava erupted is equal to the volume of lava displaced by subsidence at the caldera. The subsidence volume appears to be 0.75 square kilometers and the erupted volume aproximately 0.5 - 0.8 square kilometers. This could be coincidence since it sort of implies there has been very little new magma into the system, yet at least some change in pressure or flow must have set off initial events. It sort of suggests to me the eruption should continue as lava at the surface should have less volume than magma compressed in a magma chamber. It concerns me that too much might be read into the match in volumes.

 

GPS movements seem slight and to reflect the current wind direction.  Tremor charts seem to show increased activity yet most of that will be due to weather conditions, but a light pick up in the 0.5 to 1 hz range might suggest a slight uptick at the eruption sight.

[jonboy]

Monday

20.10.2014 13:58:57 64.672 -17.419 3.8 km 3.0 99.0 6.2 km NE of Bárðarbunga

Monday

20.10.2014 13:31:06 64.659 -17.376 0.2 km 4.7 99.0 7.5 km ENE of Bárðarbunga

Monday

20.10.2014 13:30:17 64.666 -17.399 3.2 km 4.1 99.0 6.8 km ENE of Bárðarbunga

Monday

20.10.2014 13:27:57 64.671 -17.450 3.2 km 4.6 99.0 5.0 km NE of Bárðarbunga

[swebby]

??????????

 

 

Hi JP - I think this coincides with the very shallow 4.7M EQ.  Maybe some kind of pressure ridge in the ice cap reorganising itself after that quake? 

 

Although if you were to tie this in to the tremor charts all being on the rise and that not being down to weather, then maybe something is happening in the caldera.

[The PIT]

Looks like the subsidence in caldera is coming to an end. Next question how long will this go on for?

[Gael_Force]

Afternoon Bungabuddies

 

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

 

@ MIA,the Mila cams are 20 km away from the fisure eruption and 60 km from Bardabunga,so i don't think there will be any subsidence there

 

this is a snapshot @ the fisure site from the Vaðöldu webcam pointing West,

 

m141019164022050.jpg

 

this looks closer to the fisure than the Mila cams and further down the hill too,i have been trying to find a live feed but no success

 

only @ this site with updated stills every minute.

 

http://icelanderuptions.com/

 

Hi Allseasons-si, that webcam is one on this page below - only live with Iceland isp (I think) - these are ten minute captures.

 

http://vefmyndavelar.mogt.is/

 

Huge uptick in some of the infrasound wave stations after the triple earthquakes this afternoon: then again, maybe just the storm arriving.

 

[Gael_Force]

??????????

 

 

A very large spike on the VON graph just before then - something out of the norm but does it lead to any change overall?

 

Edited October 20, 2014 by Gael_Force

[john pike]

Monday

20.10.2014 17:58:00 64.688 -17.450 7.6 km 3.4 99.0 6.5 km NE of Bárðarbunga Monday

20.10.2014 15:58:58 64.671 -17.460 4.7 km 3.3 99.0 4.7 km NE of Bárðarbunga

20.10.2014 13:58:57 64.672 -17.419 3.8 km 3.0 99.0 6.2 km NE of Bárðarbunga Monday

20.10.2014 13:31:06 64.659 -17.376 0.2 km 4.7 99.0 7.5 km ENE of Bárðarbunga Monday

20.10.2014 13:30:17 64.666 -17.399 3.2 km 4.1 99.0 6.8 km ENE of Bárðarbunga Monday

20.10.2014 13:27:57 64.671 -17.450 3.2 km 4.6 99.0 5.0 km NE of Bárðarbunga Monday

20.10.2014 13:20:42 64.680 -17.424 10.1 km 3.0 99.0 6.6 km NE of Bárðarbunga Monday

20.10.2014 08:54:37 64.686 -17.462 4.2 km 5.0 99.0 6.0 km NNE of Bárðarbunga Monday

20.10.2014 07:55:16 64.672 -17.466 8.9 km 3.9 99.0 4.6 km NE of Bárðarbunga Monday

20.10.2014 06:51:04 64.672 -17.479 7.8 km 3.7 99.0 4.2 km NNE of Bárðarbunga Monday

20.10.2014 05:21:22 64.683 -17.464 8.9 km 4.5 99.0 5.6 km NNE of Bárðarbunga Monday

20.10.2014 04:29:03 64.681 -17.422 7.9 km 3.6 99.0 6.7 km NE of Bárðarbunga Monday

20.10.2014 01:00:23 64.612 -17.431 8.3 km 4.8 99.0 5.6 km SE of Bárðarbunga Monday

20.10.2014 00:38:21 64.619 -17.398 9.3 km 4.2 99.0 6.6 km ESE of Bárðarbunga

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

 

all the plus 3 quakes today

 

the uplift earlier on the gps was an odd one

 

what could cause the reading to lift 2 mtres then drop back down again

 

could a shallow quake lift the ice above it 2 m (unlikely)

 

possibly the power of the quake was that strong it flipped it upwards (not sure)

 

weather?????  again a few inches would be likely but not 2m

 

possible magma chamber full and it took the quake to free it through dike (possible)

 

all ifs and buts this

 

meeting of scientists today

 

http://en.vedur.is/media/jar/Factsheet_Bardarbunga_20141020.pdf

 

still no change...

 

its a shame no cameras tonight

 

 

http://services.swpc.noaa.gov/images/aurora-forecast-northern-hemisphere.png

 

probably would have seen some lights from the sky too

Edited October 20, 2014 by john pike

[john pike]

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

 

maybe we will see it

[john pike]

 

looks like another bigish quake there

[Allseasons-Si]

??????????

 

Evening John

 

that is some spike there,i maybe wrong but that looks like a presure explosion,but three meters is a lot to shift fourty billion tons of ice + the caldera(don't know the weight)

 

three more +3's in

 

Monday

20.10.2014 21:09:21 64.686 -17.481 8.7 km 3.8 99.0 5.5 km NNE of Bárðarbunga

Monday

20.10.2014 20:52:34 64.680 -17.506 7.3 km 3.2 99.0 4.5 km NNE of Bárðarbunga

Monday

20.10.2014 20:50:48 64.677 -17.443 3.3 km 3.4 99.0 5.8 km NE of Bárðarbunga

 

curtainly busy today

 

it's nice to see some checked quakes coming in

 

no vis on the cams though,beggers can't be choosers

 

poss 4+ EQ coming

 

Monday

20.10.2014 22:18:23 64.670 -17.426 1.1 km 2.2 90.1 5.9 km NE of Bárðarbunga

 

Edit:make that 2

 

http://baering.github.io/

 

a 4.5 here,it could be a 5

 

http://www.emsc-csem.org/Earthquake/earthquake.php?id=405071

Edited October 20, 2014 by Allseasons-si

[john pike]

hi allseasons

 

 

this activity is rising quite a bit now

 

how much can bara take??

 

no idea but i feel somethings brewing

 

 

its plain where most of the quakes are now

 

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

 

17 fairly large quakes today and barring 1

 

they have all been deep which means the feed is probably increasing

 

shame no cams but can still get an idea from the quakes whats going on

[Allseasons-Si]

hi allseasons

 

 

this activity is rising quite a bit now

 

how much can bara take??

 

no idea but i feel somethings brewing

 

 

its plain where most of the quakes are now

 

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

 

17 fairly large quakes today and barring 1

 

they have all been deep which means the feed is probably increasing

 

shame no cams but can still get an idea from the quakes whats going on

Yes John

 

same @ dyn and von with the upticks there and grm's too,just looking at that map earlier on IMO and a fair few of them EQ's are not on the caldera rim,i am not sure what that is about,still a novice here

 

ok,Barda is angry now,he! he!

 

http://baering.github.io/

 

Monday

20.10.2014 23:04:48 64.681 -17.434 6.0 km 3.8 99.0 6.3 km NE of Bárðarbunga

Monday

20.10.2014 22:49:22 64.671 -17.471 6.6 km 3.9 99.0 4.3 km NE of Bárðarbunga

Monday

20.10.2014 22:18:23 64.671 -17.444 3.8 km 4.6 99.0 5.3 km NE of Bárðarbunga

Edited October 20, 2014 by Allseasons-si

[john pike]

hi allseasons

 

http://en.wikipedia.org/wiki/Earthquake

 

probably easier to let you read the link

 

its interesting

 

hope that helps

 

john

[john pike]

one more showing of what the quakes today over 3 look like

 

Monday
20.10.2014 23:04:48 64.681 -17.434 6.0 km 3.8 99.0 6.3 km NE of Bárðarbunga Monday
20.10.2014 22:49:22 64.671 -17.471 6.6 km 3.9 99.0 4.3 km NE of Bárðarbunga Monday
20.10.2014 22:18:23 64.671 -17.444 3.8 km 4.6 99.0 5.3 km NE of Bárðarbunga Monday
20.10.2014 21:09:21 64.686 -17.481 8.7 km 3.8 99.0 5.5 km NNE of Bárðarbunga Monday
20.10.2014 20:52:34 64.680 -17.506 7.3 km 3.2 99.0 4.5 km NNE of Bárðarbunga Monday
20.10.2014 20:50:48 64.677 -17.443 3.3 km 3.4 99.0 5.8 km NE of Bárðarbunga Monday
20.10.2014 17:58:00 64.688 -17.450 7.6 km 3.4 99.0 6.5 km NE of Bárðarbunga Monday
20.10.2014 15:58:58 64.671 -17.460 4.7 km 3.3 99.0 4.7 km NE of Bárðarbunga Monday
20.10.2014 13:58:57 64.672 -17.419 3.8 km 3.0 99.0 6.2 km NE of Bárðarbunga Monday
20.10.2014 13:31:06 64.659 -17.376 0.2 km 4.7 99.0 7.5 km ENE of Bárðarbunga Monday
20.10.2014 13:30:17 64.666 -17.399 3.2 km 4.1 99.0 6.8 km ENE of Bárðarbunga Monday
20.10.2014 13:27:57 64.671 -17.450 3.2 km 4.6 99.0 5.0 km NE of Bárðarbunga Monday
20.10.2014 13:20:42 64.680 -17.424 10.1 km 3.0 99.0 6.6 km NE of Bárðarbunga Monday
20.10.2014 08:54:37 64.686 -17.462 4.2 km 5.0 99.0 6.0 km NNE of Bárðarbunga Monday
20.10.2014 07:55:16 64.672 -17.466 8.9 km 3.9 99.0 4.6 km NE of Bárðarbunga Monday
20.10.2014 06:51:04 64.672 -17.479 7.8 km 3.7 99.0 4.2 km NNE of Bárðarbunga Monday
20.10.2014 05:21:22 64.683 -17.464 8.9 km 4.5 99.0 5.6 km NNE of Bárðarbunga

Monday
20.10.2014 01:00:23 64.612 -17.431 8.3 km 4.8 99.0 5.6 km SE of Bárðarbunga Monday
20.10.2014 00:38:21 64.619 -17.398 9.3 km 4.2 99.0 6.6 km ESE of Bárðarbunga

 

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

 

all north or north east except the bottom 2

Edited October 20, 2014 by john pike

[Allseasons-Si]

Thanks for the wiki John,a long read but well informative

 

lets se what Barda brings tomorrow

 

goodnight mate.

[john pike]

nite mate

 

that looks like a big quake there

[Allseasons-Si]

nite mate

 

that looks like a big quake there

Are you trying to keep me awake lol

 

catch u tomorrow.

Edited October 21, 2014 by Allseasons-si

[john pike]

ha ha sorry mate

 

going myself now

 

looks like it might keep lively

 

goodnight mate

 

[jonboy]

Tuesday

21.10.2014 08:36:35 64.694 -17.442 15.6 km 5.3 99.0 7.3 km NE of Bárðarbunga

Tuesday

21.10.2014 08:34:47 64.673 -17.458 6.7 km 4.7 99.0 5.0 km NE of Bárðarbunga

The 5.3 is deep at 15.6km wonder what is moving down below!!

[swebby]

Hmmm, I do agree about the 15.6Km depth being noteworthy. 

 

Not sure we have had something of that magnitude at that depth below the caldera.  May simply be a release of stress on a fault as the magma chamber empties but I imagine it could equally be the start of a new rifting episode?