So, farewell then, the Holuhraun eruption; the flow of lava turned off to end with a whimper not a bang. Yes, the eruption which began in Iceland’s Bárðarbunga volcanic complex in August 2014 is finally over. But it’s left its mark.
At Decoded Science we’ve been keeping abreast of the declining seismic and eruptive activity in Iceland by following the regular briefings issued by Iceland’s Scientific Advisory Board.
But like everything else these days, or so it seems, the news broke on Twitter, with volcanologist John Stevenson tweeting on 27 February: “#Bardarbunga eruption over? Iceland coastguard film crater with no glowing lava visible.”
And on Saturday, 28 February, the news was officially confirmed in a bulletin from Iceland’s Department of Civil Protection and Emergency Management, announcing that: “The volcanic eruption in Holuhraun, which began on August 31st 2014, has come to an end.”
The Bárðarbunga Eruption of 2014-15
Bárðarbunga, taking place as it did in the eye of the media (with a live appearance on Good Morning America, for heaven’s sake), should probably be measured in more than just numbers; and in any case the final statistics by which it will be known (its area, its erupted volume, its gases) aren’t yet published.
What we can say for certain is that the eruption lasted 181 days. We can say that it generated huge amounts of news coverage. We know that by January it had produced enough lava to cover over 32 square miles (an area larger than Manhattan) and an estimated volume of over a cubic kilometre (data reported by NASA).
Oh, and it changed its name three times in the course of its short life. First it was an eruption of Bárðarbunga; then it acquired the name Holuhraun; and at the time of its demise the media were beginning to refer to it as Nornahraun, or ‘Witch’s Lava.’
The Grand Scheme of Things
Although the 2014-15 eruption produced enough material to qualify as a flood basalt rather than just a lava flow (it’s a matter of scale) it isn’t by any means the largest such eruption in Iceland — large areas of which are made up of precisely such lava fields. It is, however, that largest since the notorious Laki eruption of 1783-4.
The Laki eruption dwarfed Bárðarbunga/Holuhraun/Nornahraun, lasting for around eight months and erupting a vast quantity of material. The British Geological Survey sums it up: “The eruption produced approximately 15 km3 of lava that flowed to cover an area of approximately 565 km2, and produced about 0.4 km3 of tephra (rock fragments and particles)… [It] emitted about 122 megatons of sulphur dioxide into the atmosphere.”
The 2014-15 event generated enough emissions to cause health concerns but Laki’s sulphur dioxide emissions proved fatal both within Iceland and elsewhere, generating enough sulphate aerosols to cool the climate, cause famine across Europe and even, it’s argued, help trigger the French Revolution.
What Next For Holuhraun?
Who knows? The complex may erupt again, in the near future, either from the same vents or from elsewhere; or it may not (volcanoes are unpredictable things).
If Bárðarbunga doesn’t erupt again, it will erode over time to a mossy green lava field typical of much of Iceland’s rift area, eventually becoming part of the country’s typical, lava-hewn scenery.
It’s almost a shame to see the eruption at Holuhraun come to an end. In its way it was an exemplary, user-friendly example of Nature at its best — extraordinary displays of power; tremendous photographs of fire and ice as winter closed in and the snow fell; a major contribution to scientific learning; and no-one injured. It may be a while before we see its like again.