Update, February 28, 2015, 4:42 p.m. Pacific: It’s a wrap!
Update, February 24, 2015, 11:52 a.m. Pacific: Wow! Not a single update in almost a month. This wasn’t laziness – the Bardarbunga eruption has been waning in intensity. However, according to volcanologist Ármann Höskuldsson, per the Iceland Review, the bulk of the magma remains underground – only about 1% has been erupted (or 2 cubic kilometers, over an area of more than 80 square kilometers). It could still be erupted through the Bardarbunga caldera (as we saw in last Sunday’s Thrihnukagigur video, some Icelandic eruptions happen through fissures rather than the main system under the crater. Dr. Höskuldsson also said something about divergences, but although I ran the linked article through a machine translator, I really don’t understand what that’s about.
January 29, 2015: Aviation code: Orange. We’re starting month six today. Wow! Can you imagine the disruption it would have caused if the eruption of Eyjafjallajökull, that Icelandic volcano that shut down North Atlantic air traffic in 2010, had lasted as long as this one at Bardarbunga?
It’s really amazing that the Bardarbunga eruption has gone on this long. Here is what the scientists had to say about it on January 27th (emphasis added):
27.01.2015, 11:00 UTC – Conclusions of the Scientific Advisory Board of the Icelandic Civil Protection:
Attending: Scientists from Icelandic Met Office and the Institute of Earth Sciences University of Iceland along with representatives from the Icelandic Civil Protection, the Environmental Agency of Iceland and the Directorate of Health.
The volcanic eruption in Holuhraun continues. Visible intensity of the eruption was low on last Wednesday while various observations were done at the eruption site. Comprehensive cross-section measurements from air (on 30. December and 21. January) show however that the lava field has thickened substantially during these three weeks and that the volume of the lava field is now little less than 1.4 km3. The flow of magma, during this period, was just under 100 m3 per second. The intensity of the eruption is there for slowly decreasing but hopefully it will be possible to measure the volume of the lava field again later this week, which will give new numbers on the flow of magma.
- Seismic activity in Bardarbunga continues to be strong. Eight earthquakes between M4.0-4.9 have been detected since the last meeting of the Advisory Board on Friday. The strongest one was measured M4.9 on Saturday, 24. January at 07:25. About 40 earthquakes between magnitudes M3.0-3.9 were detected over the period. In total around 150 earthquakes have been detected around the caldera since last Friday. No earthquake over M5,0 has been detected in Bardarbunga since 8. January.
- Around 50 earthquakes were detected in the dyke during the same period. Most of them were under M1.0 but the strongest one was M1.6 on 24. January.
- GPS measurements near northern Vatnajokull glacier show continuing slow deflation towards Bardarbunga…
…The volcanic eruption has now been going on for little less then five months, the lava flow is still great in Holuhraun and the rate of the subsidence of the Bardarbunga caldera is still significant. Three scenarios are considered most likely:
- The eruption in Holuhraun continues until the subsidence of the Bardarbunga caldera stops. The eruption can still go on for many months.
- The volcanic fissure may 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. If such an eruption would be prolonged it could eventually produce a lava flow.
- Volcanic eruption in the Bardarbunga caldera. Such an eruption would melt large quantities of ice, leading to a major jokulhlaup, accompanied by ash fall.
Other scenarios cannot be excluded.
Per an overflight (PDF) on January 21st, “Observations from the previous surveillance flight held on 10 JAN had already indicated that the intensity of the eruption had decreased since early DEC 2014. Observations made on 21 JAN not only confirm this, but also indicate that the intensity of the eruption has decreased (markedly) further.”
Nonetheless, it’s still impressive:
By the way, this eruption reportedly has an unusual large amount of gas for the amount of magma involved, but it is nowhere near the amount that Bardarbunga’s neighbor Laki unleashed on Iceland and world back in the 18th century.