The Ultimate Guide to Volcanoes in Iceland

Volcanoes in Iceland sometimes erupt in dramatic fashion, causing the world to sit up and take notice. Have you ever wondered what it might be like to visit some of them? Geologically, Iceland’s a young country and one of the most tectonically active places on earth. Volcanic eruptions happen from time to time, but even in the absence of lava flows and towering ash clouds, they are well worth seeing. Here’s what you need to know with our ultimate guide to volcanoes in Iceland. 

How many active volcanoes are there in Iceland?

You’d think it would be easy to count how many active volcanoes in Iceland there are. In fact, that’s a surprisingly tricky question to answer, so let’s start by defining what we mean. A volcano is a type of mountain that has a magma chamber beneath it. During an eruption, lava, ash, rocks and gas may be ejected through a crater, vent or fissure in the earth’s crust. 

Volcanoes can be classed as active, dormant and extinct. Put simply, that means they’re doing something, sleeping or dead. However, there’s no agreed definition of an active volcano. To be described as such, experts state that a volcano must have erupted relatively recently (the precise time period is the part that varies) and be capable of doing so again. In contrast, a dormant volcano has been slumbering for many years and is expected to remain that way for the foreseeable future.

The issue of connectivity also hinders the count. Volcanic systems may be linked underground out of sight, making it difficult to work out where one ends and another begins. So how many are we talking about? According to the Catalogue of Icelandic Volcanoes, one of the country’s most reliable sources, there are 33 active volcanoes in Iceland.

What kinds of volcanoes are there in Iceland?

The most common type of volcano in Iceland is the stratovolcano; these are cone-shaped in appearance and usually have a crater in the top. Katla and Hekla would be famous examples of stratovolcanoes in Iceland. But some of Iceland’s volcanoes don’t look like this at all. Instead, they are what’s called shield volcanoes. Much flatter, they tend to have less explosive eruptions that are often characterised by slow flowing lava. Fagradalsfjall on the Reykjanes peninsula is probably the best known example, as since the 2021 eruption it has been evolving into this type of volcano. 

Another thing to note is that because glaciers cover many volcanoes, Iceland experiences something known as jökulhlaups. These outburst floods can be triggered by geothermal heat from the volcano. They have the potential to cause serious damage to property as well as force local people and livestock to evacuate until the threat has passed. 

Why are there so many active volcanoes in Iceland?

Iceland sits above what’s known as a hotspot. Scientists also refer to it as a magma plume. This means that magma can be found very close to the surface, forming land and generally making its presence felt in the form of eruptions. Volcanoes in Iceland loosely following the line of the Mid-Atlantic Ridge where the North American tectonic plate is pulling apart from the Eurasian. This is the cleft in the landscape that you’d be standing above when you cross the Bridge between Continents on the Reykjanes Peninsula or visit at Thingvellir National Park as part of a Golden Circle tour. A few volcanoes are also found along the Snæfellsnes and Öraefajökull Volcanic Belts.

Where do you find volcanoes in Iceland? 

Typically, the volcanoes in Iceland form a southwest to northwest cluster along the Mid-Atlantic Ridge. You can visit many of them although some remain out of sight, hidden beneath glaciers so you can’t actually see their rocky flanks or craters. These are some of the most significant: 

Fagradalsfjall 

Fagradalsfjall, on the Reykjanes peninsula, had been dormant for many centuries before rousing itself in 2021. For around six months, lava flowed almost constantly from its crater, drawing a crowd of open-mouthed visitors. After a brief quiet spell, the action kicked off again in August 2022 for a second, short-lived eruption. 

Bárðarbunga

Iceland’s most active volcano is actually Bárðarbunga, which has experienced more than 20 verified eruptions in the last 11 centuries. Its most significant eruption took place around 8600 years ago. However, it’s been making its mark ever since and last erupted between August 2014 and February 2015, an event that caused the collapse of its crater..

Eyjafjallajökull

Eyjafjallajökull hit the headlines in 2010 after this hitherto unremarkable volcano sent a huge ash cloud into the sky. Though there was little danger on the ground – residents were evacuated safely – it had a noticeable effect on farming. The ash cloud also impacted the busy North America to Europe flight corridor meaning that air traffic was grounded for six days. It made headlines across the world to the horror of news anchors, who had to try to pronounce its name.  

Katla

Katla is concealed beneath the Mýrdalsjökull glacier, a sleeping giant that if awaken could create a massive explosion. The resultant ash cloud would potentially dwarf that seen above Eyjafjallajökull more than a decade ago. In the past, eruptions of Eyjafjallajökull have been followed soon after – usually within months – by a bigger event on Katla. This time, however, geologists only identified a small sub-glacial eruption, so watch this space. 

Hekla

This stratovolcano is located in the south of Iceland. It’s a large volcano that erupts relatively frequently, causing early settlers to dub it the “Gateway to Hell”. Around 10% of the tephra found in Iceland came from one of Hekla’s eruptions. Incidentally, this volcano is not a symmetrical cone. Instead, some liken its shape to an upturned boat. It has at least two significant craters. 

Are there warning signs that precede an eruption?

It’s possible for a volcano to erupt with little or no warning. In practice, however there are a number of indicators that vulcanologists monitor so that they can take the necessary steps to keep members of the public and their property safe if things kick off. They record any changes to the shape of the ground, levels of gas emissions and seismic activity. 

It’s of interest to find out whether an earthquake swarm has occurred. Many tremors, if taken on their own, would be considered fairly insignificant, measuring less than 3 or 4 on the Richter scale. However, as part of the bigger picture even these small quakes could be of greater concern. 

For example, over the course of a month prior to the eruption of Fagradalsfjall volcano in 2021, more than 53000 earthquakes were recorded. But plate tectonics is a relatively new science and experts are learning all the time. Even a significant change in activity doesn’t always result in a full-on volcanic eruption.

Planning your visit to an Icelandic volcano

Many people understandably question whether it is completely safe to visit an Icelandic volcano. The answer is no, of course: volcanoes are dangerous and unpredictable. Sometimes the most closely monitored volcanoes can do unexpected things and even professional vulcanologists can be caught unawares. 

But life is about balance – pretty much everything we do has some kind of risk involved. We could be knocked over by a passing car, yet we still cross the road. Planes sometimes crash but we board them quite happily for non-essential reasons like taking a holiday. And so it is with volcanoes: a visit will never be totally without risk. We should do our homework, use common sense and heed the warnings we’re given by the authorities before coming to our own decision about whether we should go or not at any given time.

Follow those steps and a visit to at least one of these volcanoes in Iceland is usually a risk that’s worth taking. And if you’re lucky enough to experience an eruption, it will be one of the most unforgettable and undeniably awesome things you’ll ever witness in your life. 

Visit the Volcano Exhibit in Reykjavík: Forces of Nature

In Reykjavik’s own Perlan, you can experience the power of volcanoes and earthquakes. Including a full show of the recent eruptions of Geldingadalir. So if your not able to visit an active volcano, Perlan's interactive museum is the way to go!