After rumbling at us all week with unconfirmed subglacial eruptions and tormenting volcanologists to debate will it or won't it erupt, Bárðarbunga belched forth a fountain of lava. The eruption was both gentle and short-lived with no ash, boding well for air travel.
Bárðarbunga started erupting just after midnight local time with a gentle, burbling fissure eruption. Webcam screenshot
Bárðarbunga starting erupting just after midnight local time on Holuhraun north of Dyngjujökull. Initial sleepy assessments were that it was a 300 to 400 meter long fissure eruption; that estimate was soon downgraded to 100 meters with low lava fountains. It fizzled out by 4am, but fissure eruptions can wax and wane repeatedly so it might not be finished yet. If the eruptions stay like this polite burble, the volcano will not produce ash clouds and poses minimal threat to air travel.
Flyover at 10:41 and 10:44 am on the morning following the eruption. Image credit: Icelandic Coast Guard
The best-placed webcam to watch the eruption live is here, although no promises it'll actually be erupting when you look. If you're feeling impatient (or get unlucky in your timing and have nothing to see), here's the first hour of the rather underwhelming eruption sped up to just 36 seconds. You can see more photographs and video of the continuing steam clouds marking the fissure here.
— BBC Weather (@bbcweather) August 29, 2014
The Coast Guard flew science teams out to the site after sunrise, confirming the characteristics of the eruption and monitoring it for any changes. The eruption was along an old fissure, with approximately 600 meters active during the peak of the eruption. Within four hours, all the lava had drained from the fissure, stopping the eruption. By the time of the flyover, only steam was emerging in white puffs, with no substantial ash. The science team concluded the most likely outcomes going forward are:
- The migration of magma could stop, resulting in a gradual reduction in seismic activity and no further eruptions.
- The dike could reach the Earth's surface north of Dyngjujökull causing another eruption, possibly on a new fissure. Such an eruption could include lava flow and (or) explosive activity.
- The intrusion reaches the surface and an eruption occurs again where either the fissure is partly or entirely beneath Dyngjujökull. This would most likely produce a flood in Jökulsá á Fjöllum and perhaps explosive, ash-producing activity.
Although unlikely, a major caldera eruption cannot be ruled out.
After teasing scientists all week with the potential for an eruption, Bárðarbunga finally stepped up with an active eruption just as soon as I got to Dragon Con. I don't know what the inanimate, geologic equivalent of crossing its legs is, but I'm suspicious the volcano has been deliberately holding off erupting for the least convenient moment. To read more on Bárðarbunga's eruption from a geoscientist who can push updates as the observations come in, check out Erik Klemetti's Eruptions Blog.
Special appreciation to science blogger Jón Frímann who noticed the eruption on webcam and brought it to our collective attentions. Check out fieldwork photos from the Met Office here, an extensive history of the volcano here,