iceland Bárðarbunga and Askja - Volcanic Activity

[john pike]

Sunday

21.09.2014 23:08:43 64.658 -17.350 0.9 km 3.5 99.0 8.7 km ENE of Bárðarbunga Sunday

21.09.2014 23:19:27 64.668 -17.474 0.5 km 2.4 99.0 4.0 km NE of Bárðarbunga

v shallow

 

im off to bed

 

 

i have a feeling its about to pick up again

[Allseasons-Si]

Sunday

21.09.2014 23:08:43 64.658 -17.350 0.9 km 3.5 99.0 8.7 km ENE of Bárðarbunga Sunday

21.09.2014 23:19:27 64.668 -17.474 0.5 km 2.4 99.0 4.0 km NE of Bárðarbunga

v shallow

 

im off to bed

 

 

i have a feeling its about to pick up again

 

 

I will keep a lazy eye on it John for the next hour then i am done

 

oh!,here we go again,seems like gps(gulps per second) has had more than me this evening lol

 

[NorthNorfolkWeather]

Just the 3 overnight that are over M3.

 

Date Time Latitude Longitude Depth Magnitude Quality Location Monday
22.09.2014 05:28:28 64.677 -17.473 4.9 km 3.5 99.0 4.9 km NNE of Bárðarbunga Monday
22.09.2014 03:13:57 64.683 -17.495 8.7 km 3.7 99.0 5.0 km NNE of Bárðarbunga Monday
22.09.2014 00:19:07 64.683 -17.488 8.9 km 3.6 99.0 5.1 km NNE of Bárðarbunga

 

 

Look how close the earlier two are, looks like about 100m between them horizontally and 200m vertically.

Edited September 22, 2014 by NorthNorfolkWeather

[BrickFielder]

  Looks like we had two ice quakes on Saturday.

 

20.09.2014    15:35:14  Depth 0.0 km strength 0.7     5.1 km ENE of Bárðarbunga

20.09.2014    14:07:33  Depth 0.0 km strength 1.3     3.8 km SE of Bárðarbunga

 

Both are slightly away from the caldera rim.

 

Also some very shallow quakes Saturday evening

 

20.09.2014    19:32:41 Depth 0.1 km strength 1.3    6.9 km ESE of Bárðarbunga

20.09.2014    19:26:34 Depth 0.1 km strength 1.5    4.1 km NNE of Bárðarbunga

 

This could be ice quakes or reverse faulting.

 

There was also quite a large earthquake which was very shallow on Saturday

 

20.09.2014    17:05:47 Depth 0.1km strength 4.4    3.6 km SSE of Bárðarbunga

 

That definately looks like reverse faulting as it is not on the rim.

 

Sundays 5.5 magnitude earthquake which caused the drop was down at a depth of 8.9 km and probably on a ring fault (7.1km ESE). This suggests that the ring faults might be quite vertical (more likely to slip) or that an upper magma chamber floor could be collapsing into a lower chamber.

 

 

Today sees a quite deep earthquake

 

22.09.2014    03:39:00 Depth 11.6 km strength 1.4    4.5 km ESE of Bárðarbunga

 

That looks more central than on the caldera edge.

 

I am also seeing more evidence of once earthquake triggering another.

 

22.09.2014    03:13:57    Depth 8.7 km strength 3.7   5.0 km NNE of Bárðarbunga

22.09.2014    03:16:33    Depth 9.1 km strength 1.4   5.0 km NNE of Bárðarbunga

 

Interesting that the sequence was downwards rather than upwards.

 

Earthquake map for Vatnajökull seems to show activity migrating more towards the ice.

 

GPS Map seems to show GFUM SIL moving towards the eruption site (could be ice on the antenna again) which might suggest a new fissure could open up towards the ice. Over stations dont show much movement at all.

 

Vertical Bardabunga chart seems to suggest periods of calm after bigger earthquakes which cause a drop. The readings look a bit more spiky recently which may be due to weather but also seems to happen just beore anoher eathquake and drop. Even the 180 minute smoothed line looks a little jolty (again could be the weather).

 

Tremor charts suggest to me show a slightly elevated amount of eruption over the last 24 hours.

 

I think it might be an idea to keep wathcing the vertical displacement Bárðarbunga to see if it steepens as I am looking at a pattern of slight weakening of the caldera floor, earthquakes triggering others (possibly more widespread slipping on ring faults rather than isolated slips), some possible ice quakes which might alter the caldera floor loading.  As ever this is all quess work so go read the experts views at the IMO or university of iceland and dont take anything I say to seriously.

[SteveB]

Another 3.4 & 4.7 quake

[john pike]

Geophysicist: Sub-Glacial Eruption Less Likely By Eygló Svala Arnarsdóttir September 22, 2014 09:19

Bárðarbunga, which lies under the northwestern part of Vatnajökull glacier. Photo: Páll Stefánsson.

Professor of geophysics Magnús Tumi Guðmundsson told ruv.is this morning that as long as the Bárðarbunga caldera is not sinking faster than it has until now and the eruption in Holuhraun remains stable, the probability of a sub-glacial eruption will decrease.

However, if the caldera starts dropping faster, or the eruption in Holuhraun subsides, then the magma will likely find another way to the surface, he reasoned.

Volcanologist Ãrmann Höskuldsson told eyjan.is yesterday that he believes the current activity will lead to a sub-glacial eruption because there is much more magma underground than is currently being emitted at Holuhraun.

The caldera subsidence also indicates a sub-glacial eruption, although it is impossible to predict when it would start, he added.

According to Magnús Tumi, it is unusual that an eruption remains stable for such a long time. The Holuhraun eruption has now lasted three weeks and one has to go all the way back to the 1963-1967 eruption which created Surtsey island to find a comparable eruption.

The new lava in Holuhraun now covers 37 square km (16 square miles) and would cover most of Iceland’s capital, as seen on this map.

 

http://icelandreview.com/news/2014/09/22/geophysicist-sub-glacial-eruption-less-likely

 

make what you will of this

 

that to me says just watch and see what happens

 

http://icelandreview.com/news/2014/09/21/someone-there-watching

 

also not sure this has been posted

 

interesting pic from nasa

Edited September 22, 2014 by john pike

[john pike]

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

 

mila cams are back up again

 

it looks like there has been some more quakes but not showing yet

Edited September 22, 2014 by john pike

[john pike]

 

none????

 

for a couple of hours

 

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

[Dorsetbred]

 

none????

 

for a couple of hours

 

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

OK John care to explain what that's about? Going quiet!

[john pike]

hi dorset

 

theres a chance these are not updated yet

 

leave it for another hour to see what happens

[jy]

Whilst not  really understanding the technical terminology ect, I must say that this has been a really compelling forum to visit.Although its been ebbing and flowing,no pun intended between safe and not so safe,the implications would be far reaching no doubt should something unexpectably bad transpire.

To those of you that have posted regularly and with knowledge too a big thank you,very interesting forum indeed.

[john pike]

http://www.globalchange.umich.edu/globalchange1/current/lectures/nat_hazards/nat_hazards.html

 

worth a read

 

the gap may be due to reporting

 

or the magma has had no blockage for that time

 

there is a third option but will leave that one for now

[john pike]

hi bjay

 

thanks

 

i am watching that waiting for more funnels

 

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

[john pike]

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

 

[The PIT]

Aaah some tremors now recorded again. Looks like a slight volcanic rest.

[john pike]

http://earthice.hi.is/bardarbunga_2014#Publications

 

that has a lot of info there

[john pike]

 

now lets see if this picks up and shows a quake

 

has spiked up again

[If Wishes made Weather]

Strangely, the last quake showing on JonFr's geophone plot about half an hour ago - which I would put at a large 3 or small 4, has not been picked up on the CSEM site?  Also no site of it yet on 3d Bulge?

[john pike]

hi tim

 

its there but not there

 

http://hraun.vedur.is/ja/drumplot/von.png

 

[If Wishes made Weather]

Hello John - something about this quiet period and this missing quake is somewhat unquieting.  The GPS thing is falling off a clifff again, but that does't really mean much.  My thoughts would be that perhaps a warmer, or (more?) acidic magma is moving that is causing less friction?

[john pike]

hi tim

 

what you say is very possible

 

i also think the reports are slow coming in for whatever reason

 

hopefully we will get the updates soon

 

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

 

cam 2 looks impressive tonight

[john pike]

Updated information 22 September 2014 19:40 - from geoscientist on duty

Around 60 earthquakes larger than magnitude 1 have been detected since midnight, 24 of them are localized in Bárðarbunga. The largest was at 9:50 this morning at the southeastern end of the caldera, magnitude 4.8. The second largest was at 13:36 in the northern part of the caldera; magnitude was 4.7. Six more earthquakes magnitude 3.3-3.8 have ocurred in the caldera today. Microearthquake activity is still ongoing under northern part of Dyngjujökull as well as some microearthquakes that were detected close to Askja and Herðubreið.

 

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

[If Wishes made Weather]

Yes John - really impressive.  Imagine the chaos if this broke out in the UK.  

 

Generally on this 'eq quiet' period, I dont for a minute buy the idea that it might have stopped - at least as far as Baroarbunga is concerned as I think a slow down, when it comes, will be gradual, just as the uptick over the past few days in the frequency of larger quakes has been gradual.

[john pike]

hi tim

 

if we look at these

 

http://hraun.vedur.is/ja/oroi/allarsort.html

 

nothing there says things are dropping off as you say

 

http://earthquake.usgs.gov/earthquakes/map/

 

what i noticed earlier though is after the iceland quake ( the 4.6 one)

 

there has been an uptake of plus 5 quakes showing

 

plus a  mini swarm on the virgin islands

 

i had noticed the plus 5 quakes since this iceland eruption started have been very minimal

 

maybe a release of pressure of some sort on the plates??

 

thats only an observation mind

[john pike]

 

and that has now jumped again