Holuhraun Has Stopped Erupting, But Is It Still Dangerous?

The Holuhraun eruption finally ended on February 27 of this year after six months, leaving behind a lava field that is 85 km2 and reaches a hefty volume of 1.4 km3. Now that the eruption has ended, people might be wondering about what consequences the eruption has had on Iceland, or even further afield. Did it affect the ecosystem in any way, and has the pollution ceased along with the eruption? Can tourists finally stop Golden Circle-jerking and go explore the new lava field? Don’t despair; Grapevine’s in-house geophysicist is here to answer your questions….

No ash, just gas

As Iceland is a highly volcanically active country, we, the Icelandic geoscientists, are always preparing for the next eruption. However, this last eruption caught us off guard, as we had been expecting an eruption similar to recent ones such as Eyjafjallajökull in 2010 and Grímsvötn in 2011, where we had flash floods and airspace-disrupting ash plumes. Instead, what we got was a white gaseous plume containing high concentrations of gas and almost no ash at all. Due to our expectations for what the next eruption would look like, a lot of work had been put into models for predicting where volcanic ash would go. Fortunately though, with a few tweaks, it was possible to make use of some of the preparatory work and create a gas forecast model that could predict where potentially dangerous levels of gas were to be expected in the next 48 hours (pictured).

“So for once we can be thankful for the horrible spring we’ve had this year, as the pollution has been released at a slower rate than expected.”

For six months, 20,000-60,000 tons of sulfur dioxide (not to be confused with carbon dioxide, the pollutant most infamous for its association with the burning of fossil fuels and climate change) were emitted from the eruption site every single day. Compared to the 14,000 tons that the entire European Union releases per day, this was a massive amount of gas. Sulfur dioxide can cause breathing problems, and prolonged or highly concentrated exposure to the gas can cause respiratory illnesses and may even be fatal. The gas plume managed to reach most of Iceland and, at times, pollution levels in Akureyri and Höfn went over the legal safety limit. Despite this, no known serious health problems were reported due to the eruption (but sales of asthma medications went up!).

Even though all this gas sounds pretty bad, the pollution from Holuhraun was still nothing compared to Laki in 1783-1784, an eruption that ended up affecting the entire northern hemisphere and causing crop failure and famine in most of Europe. The smaller global effect from Holuhraun was mostly due to the low intensity and height of the plume, which caused the pollution to mostly stay in the vicinity of the eruption itself. High gas concentrations were briefly detected outside of Iceland, in countries in mainland Europe such as France, England, Sweden and Austria, but pollution levels there peaked in September and have barely been seen since. It’s highly unlikely that more pollution from the eruption will be detected now, after its end.

The season matters

Sulfur dioxide can form sulfuric acid, a chemical that has negative impacts on plant life and as such could damage Iceland’s ecosystem. Because of the time of year, a lot of the pollutants (including the sulfur dioxide) were bound in the snow rather than being released straight into the environment. As a result of this, a large sudden melt of snow would release all of these pollutants at once, with greater effects than if they had been released more gradually. So for once we can be thankful for the horrible spring we’ve had this year, as the pollution has been released at a slower rate than expected. Additionally, most of the pollution has probably already cleared at the lower altitudes of Iceland, though some could still remain at higher altitudes, such as up on the glaciers.

Another fortunate bit of season-related luck is that the timing of the eruption didn’t coincide with the growing period of plants, and there weren’t a lot of birds around either. So, animal and plant life was spared. Had the eruption happened during summer, the consequences could have been a lot worse.

But can we go see it and is it safe now?

During the first scientific field trip to the lava site after the eruption ended in late February, life-threatening gas levels were still being measured above the lava field. The area has been slowly degassing ever since and levels of pollution should be much lower at this point. The aviation colour code for Bárðarbunga has been changed back to green, meaning that “volcanic activity is considered to have ceased, and the volcano has reverted to its normal, non-eruptive state.” The current risk of an eruption happening in Bárðarbunga has become very slim, as earthquakes in the area have gone down in number and ground measurements don’t suggest that any new magma is being added to the Bárðarbunga volcanic system.

The area has finally become relatively safe from eruption hazards, but that also means that people planning to go there will have a lot less to see. There are no big, glowing and bubbling lava lakes anymore, nor rivers and waterfalls with smoke coming out of them. At the time of the eruption, the risks of flash floods in the area were simply too high for it to be safe for people other than scientists in the field for civic defensive purposes, as Iceland has a no-tolerance policy for avoidable deaths from natural disasters.

However, there is a new and massive black rock field spreading over 85 km2. The large exclusion zone around the eruption site has decreased to mainly just the lava field itself (pictured) so for those interested, it is possible to get a view of the new lava field by driving a super jeep or snowmobile to the area and doing a bit of hiking. There’s still a lot of snow in the highlands and it’s a generally dangerous and barren place to be in, so if people are planning on going there they need to bring someone with experience of the area. When travelling, caution must be taken, and always make sure someone knows where you will be travelling, what paths you are planning to take and how long you plan on being gone, as Iceland’s a beautiful but dangerous place.