[ACTUEEL] Vulkanen IJsland #18: Verhoogde activiteit bij Bardarbunga

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Op donderdag 21 augustus 2014 12:41 schreef DemonRage het volgende:
Het gerommel lijkt nu op te houden:
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Op donderdag 21 augustus 2014 12:50 schreef Pagan het volgende:

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Op donderdag 21 augustus 2014 13:06 schreef lipjes het volgende:

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Ik heb toch echt een ander beeld
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Op donderdag 21 augustus 2014 12:41 schreef DemonRage het volgende:
Het gerommel lijkt nu op te houden:
[ afbeelding ]

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Op donderdag 21 augustus 2014 13:06 schreef lipjes het volgende:

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Ik heb toch echt een ander beeld
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gislio twitterde op donderdag 21-08-2014 om 16:16:39 Scientists say a 25km long "dyke" is forming at a depth of 5-10km under #Bardarbunga - no signs of magma finding a route to the surface reageer retweet

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eruptionsblog twitterde op donderdag 21-08-2014 om 17:52:13 Most interesting bit: subsidence at Bardarbunga, which could mean magma draining from under the edifice to new intrusion to east. reageer retweet

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eruptionsblog twitterde op donderdag 21-08-2014 om 18:08:30 @jonfr500 @aficientifico Well, IMO thinks its lateral movement of magma out from the caldera to the focus of seismicity. reageer retweet

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subglacial twitterde op donderdag 21-08-2014 om 18:41:26 #Bárðarbunga A calming thought. Volcanoes are complex natural systems, and during periods of unrest scientists get a good handle on what 1/3 reageer retweet

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subglacial twitterde op donderdag 21-08-2014 om 18:43:24 #Bárðarbunga 2/3 activity lies within the 'normal' range. This usually varies from eruption to eruption - even at the same volcano. reageer retweet

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eruptionsblog twitterde op donderdag 21-08-2014 om 18:48:17 Those last two RT are important. Until a volcano becomes active, we dont have a baseline to what the range of unrest might be. (1/2) reageer retweet

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eruptionsblog twitterde op donderdag 21-08-2014 om 18:48:48 Without that baseline, it can sometimes be hard to tell if a seismic swarm might just be an intrusion or event precursory to an eruption. reageer retweet

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eruptionsblog twitterde op donderdag 21-08-2014 om 18:49:25 And most importantly, whether the precursory events are short term (eruption in days/weeks) to longer term (years? decades?). reageer retweet

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subglacial twitterde op donderdag 21-08-2014 om 18:50:00 #Bárðarbunga. Given the absence of escalation, today's summit EQs and 'slight subsidence' etc. are best regarded as 'normal'. For now. reageer retweet

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Op donderdag 21 augustus 2014 19:46 schreef DemonRage het volgende:
http://www.jonfr.com/volcano/?p=4744

Nou wordt er gesproken van een inzakking van de caldera, wat misschien een voorbode is van een caldera-instorting.

Wikipedia: Caldera voor meer info over wat het inhoudt.

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eruptionsblog twitterde op donderdag 21-08-2014 om 18:08:30 @jonfr500 @aficientifico Well, IMO thinks its lateral movement of magma out from the caldera to the focus of seismicity. reageer retweet

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Op donderdag 21 augustus 2014 19:46 schreef DemonRage het volgende:
http://www.jonfr.com/volcano/?p=4744

Nou wordt er gesproken van een inzakking van de caldera, wat misschien een voorbode is van een caldera-instorting.

Wikipedia: Caldera voor meer info over wat het inhoudt.

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Op donderdag 21 augustus 2014 13:29 schreef DemonRage het volgende:

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Hmmm. Dan waren ze vast meetgegevens aan het herzien ofzo.

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Op vrijdag 22 augustus 2014 00:17 schreef bedachtzaam het volgende:
3D, seismische activiteit en een webcam.

http://baering.github.io/

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gislio twitterde op vrijdag 22-08-2014 om 12:42:01 @subglacial Looking at http://t.co/Z6OaJxoxxR - can one interpret that activity has been going down since the large quake? reageer retweet

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subglacial twitterde op vrijdag 22-08-2014 om 12:46:00 @gislio I've been watching this carefully and there does appear to be a reduction in the magnitude of subsequent EQs since the reported M4.7 reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 12:47:46 @subglacial If magma was moving to the surface, what would be expect to see on these graphs? reageer retweet

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subglacial twitterde op vrijdag 22-08-2014 om 12:48:33 @gislio However, in 6-10 hours we will have a clearer picture of whether this is is just a temporary decline or not. Unpredictability rules! reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 12:49:53 @subglacial Exactly :-) reageer retweet

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subglacial twitterde op vrijdag 22-08-2014 om 12:50:14 @gislio You'd have to click the 'table' tab and look at the EQ depths. Ideally extract the data and construct a time vs EQ depth plot. reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 12:53:24 @subglacial Been doing that - but thought one might see a change in these graphs as well that could depict more magma movement to surface reageer retweet

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subglacial twitterde op vrijdag 22-08-2014 om 12:54:57 If current event ends soon it'll be volcanic speed dating. The longer it lasts the better we get to know #Bárðarbunga's volcanic personality reageer retweet

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subglacial twitterde op vrijdag 22-08-2014 om 12:58:11 @gislio We don't have access to the fuller datasets and better software that the #Icelandic experts have. So I'd wait for them to report :-) reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 12:59:37 @subglacial Would be nice if Iceland was fully signed up for #opendata in all of its government entities…then others could analyze :-) reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 13:00:32 @subglacial @seismo_steve Which is exactly the reason they should make all data openly available - so they could share the load of work... reageer retweet

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subglacial twitterde op vrijdag 22-08-2014 om 13:01:51 @gislio I actually feel quite priviledged and grateful that #Iceland already shares so much of its tectonic and volcanic data so freely. reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 13:03:28 @subglacial Yes they have improved greatly over the past few years. I know they were very reluctant to make data open avail back in 2010... reageer retweet

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subglacial twitterde op vrijdag 22-08-2014 om 13:04:53 @gislio Fair point. But context and experience are vital in interpreting complex data sets. #Icelanders already do this exceptionally well. reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 13:05:23 @subglacial They get so much data “to play with” so no wonder they get good at it :-) reageer retweet

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subglacial twitterde op vrijdag 22-08-2014 om 13:08:13 @gislio A problem in 2010 was that data+statements were being 'modified' by less-knowlegeable 'experts' which resulted in more confusion. reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 13:09:16 @subglacial Always an issue - but the more experts like you that get access to the data - the more voice of reason we get :-) reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 13:09:34 @subglacial Which is why I rely on experts like you and IMO to analyze the data :-) reageer retweet

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subglacial twitterde op vrijdag 22-08-2014 om 13:12:03 @gislio IMO and their co-workers are THE experts. Their reports have to be factually based. I am however free to provide wider context :-) reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 13:13:20 @subglacial Problem in small countries is that we can only afford to have a small number of experts on gov payroll…1/2 reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 13:13:53 @subglacial Open data enables us to extend that capacity to smart collaborators around the world which can help out during times of need 2/2 reageer retweet

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gislio twitterde op vrijdag 22-08-2014 om 14:30:16 Humor: Reason there is no eruption yet - we are waiting for @jtimberlake to play in #Iceland - http://t.co/9VZHNTziCh and keep him there reageer retweet

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subglacial twitterde op vrijdag 22-08-2014 om 14:46:37 #Bárðarbunga. Nice map with geological formaltions on it sourced from #ISOR in #Iceland. http://t.co/s7Uz9WMAzw. http://t.co/nCmV7cXW29 reageer retweet

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Bárðarbunga update August 22 13:12 UTC
Still on top of every Vedur page : Intense earthquake swarm continues at Barðarbunga. Presently there are no signs of magma moving to the surface. This message hasnt changed since many days
- we are noticing a decrease in the number of earthquakes the last 12 hours. Still a massive number of course
- 3 M+3 earthquakes today below the Bardarbunga volcano location BUT at a depth of respectively 8.1, 9.2 and 9 km which means in human terms far away from a possible eruption. These stronger earthquakes are meaning that the pressure of the magma continues but cannot find a way up. Less earthquakes means also usually stronger earthquakes.
- The dyke North East area of the glacier where earthquakes are currently very shallow (a lot of weak quakes at a depth of 1 km) is currently having a decrease in number of earthquakes
- Visir Iceland reports the view of a number of specialists. Every belief finds his truth
Kristín Vogfjörð, Director of Research at the Icelandic Met Office believes that based on her interpretations of the GPS data, the pressure is receding and the likelihood of eruption is minimising.
Meanwhile, Ingi Þorleifur Bjarnason, a research scholar with the Insitute of Earth Sciences at the University of Iceland interprets the data differently, believing that the pressure is increasing and that the volcano is rising in preparation for eruption.
Magnús Tumi Guðmundsson, geophysicist and professor at the University of Iceland has said that really, it could go either way.
There is definitely a chance that this will end with an eruption, the likelihood of that has not changed, said Magnús Tumi. You could say that the longer this [eruption delay] goes on the chances of an eruption will go up. But I believe that there is no more a chance that an eruption will happen than it wont. Nobody really knows.
ER believes Kristin is right (based on the current data)

Bárðarbunga update August 22 13:12 UTC
A report from RUV Iceland who quotes a lot of information from the Icelandic Met Service
A 25 kilometer long dyke intrusion has formed, north and east of the Bardarbunga caldera. Intense seismic activity continues there. Strong earthquakes have been detected in the caldera itself, but they are associated with decompression of the magma chamber beneath the caldera.
According to the Icelandic Met office there are no signs that seismicity is decreasing. A 25 kilometer long dyke has formed in the crust under the Dyngjujokull outlet glacier at 5 10 km. depth. Magma is thought to continue to move along the dyke, possibly branching out at the NE end of the dyke.
Several strong earthquakes have been detected in the Bardarbunga itself; the last one, magnitude 3,5, at around 11 GMT this morning, These events are thought to reflect an adjustment of the caldera rim, related to decompression in the caldera since the beginning of the unrest six days ago.
Land displacement measurement with GPS around the volcano show up to 14 centimeter drift since the unrest began, on August 16. Annual drift in Iceland, due to crustal plate movements, is about 2 cm.
A new GPS station in Kverkfjöll is now running and sending data. Similar seismic instruments were installed by Kverkfjöll yesterday, as well as close to the GPS station at Hamarinn, which was set up two days ago. In addition, two seismic stations set up in Dyngjujökull yesterday are collecting data on site. This work is done in collaboration between IMO, the Institute of Earth Sciences and collaborators in the European FutureVolc research project. (Icelandic Met Office).
The evacuation order for the area north of Vatnajokull is still in effect. The area north of Route 1 (including Dettifoss, Hljodaklettar, Asbyrgi) is still open to the general public.
This story, by the Icelandic National Broadcasting Service (RUV), was updated on 22 August 2014, at13.45 GMT.
ER : below in red the number and Magnitude in earthquakes since the last 4 hours. The image shows a decrease both in number and Magnitude of the earthquakes.