General Volcanic Activity Thread!

[john pike]

a bit early to say its a swarm john, but then again its just started so we never know! typically i'm just off to bed so it would start now!

hello bobbydog

sorry a bit of an early call to say a swarm

i was going to go to bed as well

typical

i will give it half an hour to see what happens.

[paul m]

Another one 23:46:3563.644-19.1431.1 km0.390.015.3 km E of Goðabunga

[john pike]

Sunday

17.07.2011 23:46:35 63.642 -19.136 0.5 km 1.4 99.0 5.6 km E of Goðabunga

upgraded to 1.4

certainly plenty of activity

[Paranoid]

Jon Frimann has a new blog post out regarding this latest set of earthquakes: http://www.jonfr.com/volcano/?p=1209

[lfcdude]

Update 1: A earthquake with the magnitude ML3.8 did happen in Katla volcano caldera at 02:02 UTC. Following this earthquake there have been many aftershocks. It is not yet clear if this means that Katla volcano is starting a eruption or not. But that should be clear in few hours if that is the case or not.

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

Edited July 18, 2011 by lfcdude

[john pike]

Magnitude ML 3.8

Region ICELAND

Date time 2011-07-18 02:02:27.2 UTC

Location 63.66 N ; 19.12 W

Depth 1 km

http://www.emsc-csem.org/Earthquake/earthquake.php?id=229435

shows as a 3.8 here as well but activity seems to have stopped for now

[bobbydog]

Magnitude ML 3.8

Region ICELAND

Date time 2011-07-18 02:02:27.2 UTC

Location 63.66 N ; 19.12 W

Depth 1 km

http://www.emsc-csem...e.php?id=229435

shows as a 3.8 here as well but activity seems to have stopped for now

hi john, well, it was a swarm! but nothing came of it. apart from the spike, the tremor graph is not showing any marked changes, however it shows the potential is still there!

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

[john pike]

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

reviewed again by the look of it and put last nights

quake back up to 3.8

Monday

18.07.2011 02:02:27 63.660 -19.116 1.1 km 3.8 90.09 7.0 km ENE of Goðabunga

[bobbydog]

nice weather over katla.....

http://www.ruv.is/katla

now would be a good time!.... boom!!!

[Paranoid]

The main focus of the activity seems to have shifted to the north-east of the caldera, during the glacial flood last week it was in the south east i think. Still some earthquakes continuing in the caldera, although they might be aftershocks from the M3.8 event.

[SteveB]

Isn't 3.8 quake fairly big for the caldera of a volcano, surely if you get that sort of magnitude quake in the caldera then somethings going on!

[Paranoid]

It's pretty sizeable yes, and it's probably associated with movement of magma beneath the surface. Katla has had larger though without an accompanying eruption (saw reference to a M4.5 in Jon Frimann's blog) What is usually more indicative of an impending eruption is harmonic tremor, so if we see a lot of that then an eruption could happen soon. Important to note though that Katla's been experiencing spikes of harmonic tremor since October last year, so i think we'd need to see something more substantial on the seismographs than occasional spikes of activity.

[bobbydog]

It's pretty sizeable yes, and it's probably associated with movement of magma beneath the surface. Katla has had larger though without an accompanying eruption (saw reference to a M4.5 in Jon Frimann's blog) What is usually more indicative of an impending eruption is harmonic tremor, so if we see a lot of that then an eruption could happen soon. Important to note though that Katla's been experiencing spikes of harmonic tremor since October last year, so i think we'd need to see something more substantial on the seismographs than occasional spikes of activity.

nothing significant at the moment but i'm watching closely :

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

[Paranoid]

The big blue spike near the 18/7 marker was probably this morning's quake. Looks like tremors are on the rise judging from the end of that graph, not sure if it's harmonic though (perhaps someone who's better acquainted with reading charts could give a yey or nay on it?)

[paul m]

Im quite a newbie to this thread so please excuse my stupidity. If Katla was to go would it be a huge eruption.

[Paranoid]

Hey Paul, it's difficult to say really. As has been said before, Katla's last eruption was over 90 years ago so we don't have knowledge (scientifically speaking) of what goes on at Katla before and during an eruption. At other volcanoes we can estimate the sort of pressure that they're under and speculate on whether it may be a large eruption or not. Based on historic records though, we know that most of Katla's eruptions that break through the ice cap are quite large (VEI 4-6), so if Katla goes into full eruption we're likely to see an eruption that's probably a few times larger than Eyjafjallajokull last year and Grimsvotn a few months ago. A very large eruption (VEI 6) could be perhaps 10-20 times larger. Alas, i'm no expert so i'm basically relaying what i've read about online, but hopefully that's answered your question at least somewhat .

Edited July 18, 2011 by Paranoid

[paul m]

Thanks paranoid. There seems to be a lot of people keeping an eye on it

[SteveB]

It's pretty sizeable yes, and it's probably associated with movement of magma beneath the surface. Katla has had larger though without an accompanying eruption (saw reference to a M4.5 in Jon Frimann's blog) What is usually more indicative of an impending eruption is harmonic tremor, so if we see a lot of that then an eruption could happen soon. Important to note though that Katla's been experiencing spikes of harmonic tremor since October last year, so i think we'd need to see something more substantial on the seismographs than occasional spikes of activity.

I didn't know Katla had a M4.5 before, there must be some serious movement under the surface.

Certainly worth keeping an eye on.

[Paranoid]

I don't know when it was, it might have been years ago for all i know, but that's just what it said on his blog and he usually seems to be quite a reliable source. I think the general point he was trying to make was that strong earthquakes aren't concrete indicators of an imminent eruption.

[john pike]

Monday

18.07.2011 19:10:47 63.642 -19.127 2.4 km 1.8 31.05 6.1 km E of Goðabunga

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

katla again

http://hisz.rsoe.hu/alertmap/site/?pageid=event_update_read&edis_id=VA-20110714-31573-ISL&uid=11116

[bobbydog]

this is mental!!

http://www.bbc.co.uk/news/science-environment-14184722

run away!!!!!!!!

[Paranoid]

New cauldrons forming on Myrdalsjokull, evidence of increased temperatures and continuing activity at Katla. More in Jon Frimann's blog, which is becoming a very useful source for this.

http://www.jonfr.com/volcano/?p=1219

[karyo]

New cauldrons forming on Myrdalsjokull, evidence of increased temperatures and continuing activity at Katla. More in Jon Frimann's blog, which is becoming a very useful source for this.

http://www.jonfr.com/volcano/?p=1219

Katla is definately keeping us interested!

Karyo

[Paranoid]

The focus for the earthquakes seem to regularly shift around in the caldera, so magma may be rising in several places. I think i saw some comment on Jon Frimann's blog about the possibility of a rift eruption, although i didn't see any scientific evidence to back that up. In my own uneducated opinion, i think Katla may still be a few months away from a major eruption. Time will tell.

[NorthNorfolkWeather]

Katla seems to be averaging just under a quake an hour at the moment, with a big spread of depth from way down at 14Km to just a few hundred metres below the surface.

From Wikipedia ( so not sure of it's veracity), it seems that the main magma chamber is about 2-3 Km down, as the peak reaches 1500 metres, this would put the main chamber just 500-1000 metres below sea level.

Doesn't seem to be much in the way of harmonic tremors at the moment, so it's still a waiting game