Irpsit August 25, 2014 at 19:35
I will repost my scenario guess-estimates:
60% of changes that magma stalls in this intrusion and then 3 things can happen: either does not erupt (20%), or erupts there (40%). If it erupts it can either form a fissure (25%) or a single-spot eruption (15%). I still think we will see the intrusion eventually stalling before reaching Askja.
30% of changes that it travels further north and then either, erupts at Askja (20%), or a slight change that it does not trigger an eruption there and continues northwards and loses pressure and the intrusion eventually dies down (10%).
10% of change that the intrusion travels slightly east into Herdubreid system and might trigger an eruption there (5%) or not (5%). But I think it is more likely if it continues northwards and it reaches Askja rather than Herdubreid.
Thus 65% changes of eruption (40% of where it currently, 20% at Askja, 5% at Herdubreid).
35% of not erupting (20% it dies down at current place, 10% it dies down around Askja further north, or 5% dies down around Herdubreid region).
So I changed my 12 guessestimated options for what is going to happen, to a few more:
More likely dike does not reach Askja. It might erupt now and or it might not.
1) localized single-spot medium sized eruption, outside the glacier, near to where it is now
2) medium sized fissure just stays that way, lenght 5 to 10km, along the line to where it is now
3) no eruption yet. Dike stays emplaced, waiting for mantle decompression or new magma arrival
4) medium sized fissure evolves towards a shield volcano
Second most likely scenario after that, is that dike reaches Askja but it can erupt or not.
5) dike reaches Askja and only causes a small eruption at Askja caldera, and nothing else
6) dike continues past Askja and stays emplaced, no eruption whatsoever, for the moment
Third and still not very likely scenario (unless we see serious mantle decompression) is a large rifting eruption, or a caldera event (if many more M5 quakes occur there)
6) large sized rifting fissure, between Askja and Bardarbunga
7) large sized rifting fissure reaching Askja, with concomitant explosive eruption there
8) large sized rifting fissure draining Bardarbunga caldera, with explosive eruption there
There are a few of unprobably scenarioes but I listed them anyways:
9) dike emplaced does not erupt but draining causes a significant explosive eruption at Bardarbunga
10) dikes stops. only a small eruption within Bardarbunga caldera
11) dike reaches Herdubreid and triggers an eruption there
12) large scale rifting eruption with eruptions at both calderas
13) Hekla does a surprise and erupts before all of this
Second, I will repost an excellent article on Askja and that we could be onto a repeat of the Holuhraun, as Peter Cobbold suggested. Circa 1862 or 1874. A Bardarbunga dike intrusion into Askja fissure swarm, but magma belonged to Bardarbunga.
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link to www.repository.cam.ac.uk (secure)]
This is the scenario that could have happened in the entire region, according to the paper and other data
Year 1862-1864: for these two years an eruption happened in part of the Veidivotn fissure AND Dyngjujokull at the same time! Both came from Bardarbunga central volcano.
Year 1873: a large eruption of Grimsvotn, similar to 2011
Year 1874: an eruption starts at Askja caldera and possibly a fissure extending southwards of Askja into Vatnajokull glacier, belonging either to Askja or to Bardarbunga. Reports of two 20km apart ash plumes are still unlocated.
Year 1875: a large fissure forms near Myvatn, formed by a very long dike north of Askja, and then Askja also goes caldera at same time.
Yer 1902/1910: possible eruptions again in Dyngjujokull, Bardarbunga central volcano and Loki-Fogrufjoll., just slightly north of Laki.
This makes me think that this decade we might see rifting, minor or larger, occuring not only where we see the current dike, but also at other regions of Iceland, especially around Vatnajokull. I would say Herdubreid, near Hamarinn, north of Tungnafellsjokull, southwest of Grimsvotn, or even outside of Katla caldera. Most these places have seen deep quakes in the past, just like Kistufell and Mt Unknown.