The Ongoing Saga: Awaiting Iceland’s Next Volcanic Eruption
The 2021 Fagradalsfjall volcanic eruption in Iceland.
There’s been lots of talk about the seismic activity right now in Iceland, so it feels appropriate to reminisce about my experience with the Fagradalsfjall eruption back in 2021.
In June of 2021, I flew to Iceland for the fourth time with the goal of witnessing the Fagradalsfjall volcanic eruption. There were so many challenges - strict covid testing, quarantine shenanigans, and bad weather forecasts. To top it off, the magma spilling out from the ongoing eruption had covered the hiking trail I wanted to take to see the volcano just days before I arrived in Iceland.
But we could figure it out, right? We didn't fly across the Atlantic Ocean to not reach our goal. I planned an alternative hiking route, trusting my geography skills and my gut that we would get a view of the volcano. And then we went off - my best friend and I tightened our boots and set out to hike up a steep, ashy ridge in extreme winds.
When we reached the top of the steep ridge, fingers and noses numb from the cold, we shielded ourselves from the wind behind a grouping of big basalt rocks. When we saw the eruption in front of us, we were both in awe -- we were watching magma from deep in the Earth bubble and spill out of the rim of a volcano. We were watching Earth create new land!
We each cracked open an Einstok beer, clinked 'em together in cheers (or skál, as they say in Iceland), and watched the eruption for as long as we could handle.
Me (hi!) with the 2021 eruption in the background.
Now, let's flash foward to today.
You may have seen on the news that there has been signficiant seismic activity happening in Iceland over the last few days. The latest seismic activity has been happening beneath the town of Grindavik, which is not far from Keflavik international airport, and is just south of the famous Blue Lagoon. You pass through this region as you go east to Iceland's capital of Reykjavik after arriving at the airport. The town of Grindavik sits on top of what geologists call the Reykjanes geothermal field.
Geothermal activity on the Reykjanes Peninsula is what allowed for the eruption at Fagradalsfjall that I saw back in 2021. The same mechanisms will be responsible for a possible eruption near Grindavik if it does happen. How fascinating is it that we might get two big eruptions in the last 2 years?
A map showing the pattern of recent earthquakes as well as the magma intrusion that cuts through the town of Grindavik. Earthquake data from the Icelandic Met Office.
So what's happening?
Grindavik sits right along the tectonic plate boundary of the North American plate and the Eurasian plate. As a result, earthquakes are very common in this area - but not like we've seen over the past few weeks.
Tens of thousands of earthquakes have been shaking the area of Grindavik since October 24, 2023. Scientists refer to these episodes of earthquakes as a seismic swarm, or a series of small earthquakes occuring in the same place over a period of time.
These earthquakes are happening along a magma intrusion. Magma intrusions form when molten rock beneath the ground begins to creep toward the surface of Earth's crust. Scientists say that as of today, this magma has an average depth of 800m beneath the ground. This might seem deep into the Earth, but on November 3rd, this magma was reported to have an average depth of 4km beneath the surface. That means, slowly but surely, it has been working its way upward.
As a result, the Icelandic Meteorological Office, which has been closely monitoring the situation, said on November 11th that "the likelihood of a volcanic eurption occuring in the near future is deemed considerable."
As of November 14, high levels of sulphur dioxide were detected within the town of Grindavik. The presence of sulphur dioxide, a gas released by magma, is usually a sign that molten rock has gotten close enough to the surface of Earth’s crust to release these toxic fumes into the atmosphere.
The town of Grindavik has been evacuated as a precaution, and the Blue Lagoon will remain closed until November 30th. All of the streets in Grindavik are closed, and for good reason: the earthquake activity caused streets to collapse. But don't be alarmed if you see photos of gasses escaping from the cracked roads while scrolling on social media -- those are just ruptured hot water pipes.
Tourists are also not permitted in the Grindavik area. There is even have a total drone ban in effect. While people like myself would love the fly over there and see what's Mother Nature has goin' on, the Icelandic government has remained dedicated to putting safety first.
A ruptured road in Grindavik. Image from The New York Times.
What will happen if a new volcanic eruption begins?
As of right now, it’s impossible to predict what is going to happen. All scientists know is that an eruption is likely, as magma continues to push toward the surface of Earth’s crust.
If the eruption occurs on land, it will most likely be an effusive eruption as opposed to an explosive one. The magma beneath this part of Iceland is known to have a low viscosity, meaning that it is very runny and flows easily. It is the type of magma that has already created the flatter, rocky lava fields that exist in Iceland today. It can move quickly and cover large areas, but will not explode violently out of the ground.
The best case scenario is that the eruption occurs north east of Grindavik, away from peoples’ homes. This would create a scenario similar to the 2021 Fagradalsfjall eruption, where the magma spilling out onto the Earth will flow onto existing lava fields. Hopefully, the eruption will occur downhill of the Blue Lagoon and the nearby Svartsengi geothermal power station, leaving those structures unscathed. In the meantime, the authorities in Iceland are preparing to construct a berm that will divert the flow of lava away from the power station.
An unfortunate scenario would be if the eruption were to begin beneath the ocean, which is possible but not likely. When magma erupts underwater, it is very rapidly cooled, causing shards of rock, ash, and steam to burst out from the sea. However, if this were to happen, it would be “locally explosive”, according to geology professor Shawn Willsey. Most likely, the larger Grindavik area would be affected, but not the whole of the country.
Contrary to what some news sources say, air traffic to Europe is most likely not at risk like it was during the 2010 eruption of Eyjafjallajokull. The 2010 Eyjafjallajokull eruption was subglacial, and magma was rapidly cooled beneath a glacier, causing shards of ash to explode into the sky. The ash was carried eastward toward mainland Europe and posed a threat to airplane engines. But again - this is not likely to happen with the new eruption near Grindavik. If you have an upcoming trip to Iceland planned, there’s probably no need to cancel.
And now we wait...
The situation in Iceland has remained unchanged for a few days as of November 15th, 2023. Small earthquakes have been occurring by the hundreds along the magma intrustion each day. Funny enough, the severity of these earthquakes has been decreasing, which is actually a sign that an eruption is more imminent than ever. The magma has now reached high enough into the surface of Earth's crust where it is no longer triggering seismic events kilometers beneath the ground.
With residents, pets, and livestock evacuated from Grindavik, all there is left for those in Iceland to do is monitor the situation and wait for the eventual eruption to begin. With fingers crossed, we can all hope for the least destructive result possible.
