Live-kuvaa löytyy muuten Youtubestakin, Mila kun toimii vähän huonosti.
Barðarbunga Volcano Livestream - YouTube
Barðarbunga Volcano Livestream - YouTube
Live-kuvaa löytyy muuten Youtubestakin, Mila kun toimii vähän huonosti.
Barðarbunga Volcano Livestream - YouTube
Thanks. Mila toimii vähän huonosti, mutta kuva on pirun hyvä silloin kun toimii.
Ilmeisesti aiemmin kuvissa näkyneet mustat pilvet olivat jonkinlainen tomu/hiekkapilvi, joita alueella ilmeisesti riittää. Purkaus on edelleen jäätikön alla käynnissä, mutta siitäkin ollaan kai kahta eri mieltä...
Tässä vaikuttaisi olevan aika asiantuntevaa kommentointia paikan päältä:
Bárðarbunga: I Hate It When Ragnarök Falls On A Saturday
Tämän mukaan suurempi purkaus olisi melkoisen todennäköinen.
Kannattaa huomioida, että juuri koillisen suunnalla Bardarbungasta sijaitsee Askja-tulivuori.Nyt tosiaan se aktiivisuus on siirtynyt käytännössä jäätikön alta pois pohjoisempaan/koillisempaan, joten jökulshlaup ei toteutuisi purkauksessakaan välttämättä. Ja Islannin seismologit ovat yhtä mieltä lopulta - eilen ei ollut purkausta, vaikka aluksi niin sanottiin. Maankuoren liikkeet reippaita ja maanjäristyksiä riittää alueella, mutta that's it tällä hetkellä.
Nyt tosiaan se aktiivisuus on siirtynyt käytännössä jäätikön alta pois pohjoisempaan/koillisempaan, joten jökulshlaup ei toteutuisi purkauksessakaan välttämättä.
Kannattaa huomioida, että juuri koillisen suunnalla Bardarbungasta sijaitsee Askja-tulivuori.
Harald Sigurdsson volcanologist says the risk of ignition from Bárðarbunga reach into the volcanic caldera system and can then ignited the highly explosive. He still believes most likely to end the current wave of magma intrusions that never reach the surface.
"It is possible that this operation can now come into the magma chamber of cardboard and it is a huge problem. Magma chamber under the caldera may contain acidic magma, ie rhyolite magma, as occurred in the eruption 1875. It was one of the larger explosive eruptions that have occurred in Iceland. And we know that when magma comes apart into the magma chamber of acidic magma, as in 1875, there will be explosive, "says Harold.
Google-kääntäjä
The seismological results are interpreted as faulting on an outward dipping cone-shaped ring fault beneath the Bardarbunga caldera. The association in time and space between the September 29, 1996, earthquake and the September 30 eruption near Bardarbunga and Grimsvötn Volcanos suggests that inflation of a shallow magma chamber, and the associated stress loading of the deeper ring fault, may be the tectonic process which generates the earthquakes.
This schematic diagram shows a possible mechanism for production of earthquakes on cone fault structures underlying the volcanic caldera. Inflation of a shallow magma chamber fed from a deeper source leads to an increase in pressure in the magma chamber, increasing stresses on rocks below the chamber. Such stress increases may lead to rupture on cone faults beneath the caldera. We note that the location of the magma source region is not well known, and may be subcrustal.
Earthquakes near Bardarbunga Volcano, Iceland
Mielenkiintoista. Ovatko Askja ja Barðarbunga samalla tavalla linkittyneet toisiinsa kuin Eyjafjallajökull-jäätikön tulivuori ja Katla?
„The 4,5 Magnitude earthquake near Askja was duly noted,“ says Magnus Tumi Gudmundsson, professor of geophysics at the University of Iceland. „Our interpretation of that event is that this is a reaction in the rock strata to the intrusion coming from the south. It causes tension, but the earthquake does not signify an impending eruption in Askja.
This is a very interesting sequence of events; big news really in a geological context, even though an eruption has´nt happened yet, and hopefully will not happen. We are looking at the active rift between the plate boundaries in the middle of the country, where much of the volcanic activity has taken place. This particular area has been relatively quiet in recent decades; an intense episode like this has probably not happened for the last hundred years, perhaps not even two hundred years.“
How much has the land spread?
„It´s difficult to say precisely. The intrusion is perhaps 2 - 3 meters wide
Seismic activity near the Askja caldera
A row of newly formed cauldrons (depressions) was spotted in the Vatnajokull glacier near the Bardarbunga volcano during a reconnaissance flight today, leading to speculation that a small eruption had begun there. Scientists estimate that 30 - 40 million cubic metres of ice have been melted.
According to a statement from the Icelandic Civil Protection Agency (CPA) early Thursday morning, three cauldrons were seen, 4 - 6 km long, 1 km wide, with a depth of 10 - 15 metres, near the southeastern rim of the Bardarbunga caldera. They are not believed to be associated with the intrusion that has been propagating to the north in recent days.
As the cauldrons are at a location on the watershed line between the northwestern and the southern part of Vatnajokull, there are indications that the meltwater has flowed to the nearby reservoir at Grimsvotn (another active volcanic site in Vatnajokull), about 20 km away.
Possible eruption near Bardarbunga
Siitähän on olemassa erittäin näpäkkää ennakkotapausta esimerkiksi vuodelta 1996, kuinka paljon sitä vettä voi tuonne etelään alueelta tulla.
Ohessa oleva pätkä on vuoden 1996 Vatnajökull:n jäätikköjokitulvasta, mutta se ei tosin ole aivan niin kuvaava kuin voisi olla. Seurasin tapausta tuolloin TV:stä ja siitä näytettiin tuolloin paljon parempaakin kuvaa, mutta jostain syystä en nyt parempaa pätkää tapauksesta löytänyt. Oheinenkin on saksankielinen.
Gletscherlauf - YouTube
Yleissivistyksen kannalta tähän yhteyteen on sopiva mainita, että Islannissa oli hetken aikaa virtaaman perusteella maailman toiseksi suurin joki vuonna 1996. Tuolloinhan siis Vatnajökull:in alla oleva tulivuori purkautui sulattaen samalla valtavat määrät jäätä, arviolta 3 kuutiokilometriä. Tulivuoren purkaus aiheutti myös Vatnajökull:in alla olevan Grimsvötn -järven valumisen tyhjiin. Järveä pidelleen jääpadon murtuessa syntui tulva, jonka virtaamaksi laskettiin jopa 45 000 kuutiota sekunnissa. Mainittakoon, että tulva-aikaan Amazonin virtaama on yli 200 000 kuutiota sekunnissa.
Within 24 hours, lava flowing from the Holuhraun fissure will enter the one of the branches of Jokulsa a Fjollum glacial river, if the advancement rate remains the same, says volcanologist Thorvaldur Thordarson. Volcanic activity in Holuhraun has not diminished since yesterday.
"If the lava flow remains steady, we should see the lava entering the riverbed sometime in the afternoon tomorrow," he says. "I do not expect much explosive activity, but we should however see some violent magna/water interaction when the lava meets the glacial runoff."
Holuhraun lava heading for glacial river
About 250 million cubic meters of magma have flowed out of the chamber, belived to be under the Bardarbunga caldera, leading to a 15 meter subsidence of the caldera itself.
"This much subsidence has never before been measured in Iceland," says geophysicist Magnus Tumi Gudmundsson, a professor at University of Iceland´s Institute of Earth Sciences in an interview. "We believe that the strong earthquakes in Bardarbunga are signs of this subsidence. We see no signs of eruptions or geothermal activity in the caldera itself, but this subsidence does however not decrease the likelyhood that something could happen in Bardarbunga," says Gudmundsson. "One theory is that the bottom of the caldera kind of floats on the magma below, and helps to push it out towards the dike intrusion, which is feeding the eruption in Holuhraun."
15 meter subsidence in Bardarbunga caldera
Three scenarios are considered most likely:
- The eruption on Holuhraun declines gradually and subsidence of the Bardarbunga caldera stops
- Large-scale subsidence of the caldera occurs, prolonging or strengthening the eruption on Holuhraun. In this situation, it is likely that the eruptive fissure would lengthen southwards under Dyngjujokull, resulting in a jokulhlaup and an ash-producing eruption. It is also possible that eruptive fissures could develop in another location under the glacier.
- Large-scale subsidence of the caldera occurs, causing an eruption at the edge of the caldera. Such an eruption would melt large quantities of ice, leading to a major jokulhlaup, accompanied by ash fall.