…and why geologists are shitting themselves right now!
In the middle of the night on Saturday, August 16, an intense swarm of seismic activity began in the area of Bárðarbunga—one of many central volcanoes nobody can pronounce—under Europe’s largest glacier, Vatnajökull. Since that day, my co-workers and I at the Icelandic Meteorological Office (aka the IMO) have been working day and night to monitor the activity, holding daily meetings with the Civil Protection services, and trying to figure out the possible outcomes of these events, which might just be the start of something a lot bigger.
When the activity began, it was incredible how we could follow the path of the magma in real-time, simply by observing the earthquakes as they moved away from Bárðarbunga. Over the span of about ten days, a 40 kilometre long magma dyke (scientist speak for “huge underground tunnel of melted rock”) had formed, spanning northeast from a centrally located volcano called Kverkfjöll to, you guessed it, another volcano, called Askja.
At just past midnight on August 29, weak signs of increased tremors were detected by some of the IMO’s seismic stations and lava was spotted on the webcams overlooking the area. This was the beginning of a small effusive eruption (a non-explosive outpour of lava) in Holuhraun, a 200-year-old lava field about five kilometres away from the glacial edge. That night I was woken by a phone call from my boss to tell me that an eruption had begun, but as nobody was in danger and I wasn’t immediately required at the office I went back to sleep knowing that the IMO could probably use some well-rested scientists come morning. It turned out that eruption only lasted about four hours, though, so I’d slept through the whole thing. Andskotans!!
Two days later, though, another effusive eruption started at a similar place but on a much grander scale, and that’s the one that is still going on today. The lava from this eruption now spans an area of more than 19 square kilometres—for scale, that’s larger than Vestmannaeyjar (17 square kilometres) and could cover most of central Reykjavík (pictured).
How’s it different from Eyjafjallajökull?
What’s going through most people’s mind right now is “”Why can’t we go see the eruption? People were allowed to see the Eyjafjallajökull* eruption, so why not this one?”” The media has been calling it another beautiful tourist eruption,” and they’re kind of right, despite the fact that an awful lot of bad gases are being emitted. Indeed, it’s a beautiful non-explosive eruption with no ash fall.
However, the Civil Protection Authority’s main reason for closing the area to anyone except scientists (and the press because they threatened the Civil Protection with a lawsuit…) is the high risk of things quickly becoming much worse. This is an area with a high risk of floods, and if another eruption were to happen under the glacier, there could be an explosive event with a lot of ash fall and catastrophic floods coming straight towards any place from where you might get a decent view of the eruption.
The good news is that it’s safe to fly over the area at the moment, so this eruption isn’t going to stop air traffic for now (sorry, happy travellers who were hoping not to have to leave the country), and people are even hiring charter flights to go and see it. I was lucky enough to go on one of the Coast Guard’s research flights over the area and got a great view of the eruption, so if you can afford it, go for it (but please don’t try to charter the Coast Guard’s plane, because we need it).
What’s going to happen next?
Well, nobody really knows. There are several different ways that this event could unfold, but things are so complex that no outcome is a certainty. We’ve never seen an eruption exactly like this one before.
Some of the most likely possibilities are:
- The magma flow could stop, meaning that there would be no more eruptions in the area for now.
- The magma could reach the surface at different locations outside the glacier, causing more effusive eruptivity similar to the eruption we are seeing now.
- The Bárðarbunga central volcano could erupt, which would produce a flood in Jökulsá á Fjöllum and explosive ash-producing activity similar to Eyjafjallajökull in 2010. This possibility is becoming more real to us scientists since the Bárðarbunga caldera has sunk over 18.5 meters, an amount never before measured in Iceland. This could make the caldera far more vulnerable to eruptive activity.
- The magma could surface elsewhere under Vatnajökull, causing similar effects to the previously mentioned possibility. We’ve seen signs of there having been small events of this type under the glacier by observing recently formed depressions in the ice, but these events have been so small that they’ve not been able to reach through the ice or cause any noticeable flooding.
- There’s also a chance that this could turn into something that lasts for years, which is known as a “rifting episode” (a spreading of the Earth due to magma inflow). The last rifting episode we had was the Krafla fires that started in 1975 and didn’t stop until 1984. These events were composed of increased seismic activity and eruptions from magma tunnels similar to what we’re seeing now.
We’re monitoring the area extremely closely and since the onset of the activity we’ve added a lot of new measuring equipment in order to help further examine the risks and possible outcomes. These events have been a firecracker under our butts to push us into finishing our work as quickly as possible so that we can make better models for better predicting the future. So, now that I’ve used my only day off work since this all started to write this article, I’m either going for some sleep or some red wine before I go back to keeping watch on Iceland with the rest of the IMO. Sjáumst and stay safe!!
* It was actually Fimmvörðuháls that was the pretty tourist eruption. Eyjafjallajökull was the one that ruined everybody’s holidays, but they are usually synonymous in most people’s minds.
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