Volcanic eruption in Iceland! It finally happened!

On Friday, the 19th of March 2021, a volcanic eruption began in the Reykjanes Peninsula, just a short drive from Reykjavík city. It’s the first time in almost 800 years we’ve had an eruption in this area. You’ve likely seen it in the news. Now get the inside scoop from Doctor Holly Spice for her second guest blog post on this active part of Iceland. Don’t worry, we’ll tag in at the end to discuss what this means for tourism in Iceland too and answer some of your frequently asked questions.

PLEASE NOTE: The volcano stopped erupting in September 2021, leaving behind a massive cooled lava field and smoking crater. Despite the lack of activity it’s still worthy of a moderate hike. 

Doctor Holly Spice is a guide for Hidden Iceland and currently holds a PhD studying the geochemistry of Icelandic basaltic lavas. She first wrote about this volcanic site prior to the eruption. You can see her detailed thoughts on the imminent eruption here

Guest writer: Dr. Holly Spice

It was first noticed on webcams and by locals to the Grindavík area as an orange glow that lit up the night sky. Over 50,000 earthquakes over a 3-week period preceded the eruption, regularly shaking Reykjavík and other nearby towns. The eruption began just as the earthquake activity seemed to be significantly decreasing, taking scientists and locals by surprise. One specialist had even been on the news earlier in the day reporting that an eruption was becoming less likely. Mother nature strikes again.

The Gerlingadalur Volcano by Dr. Holly Spice. Hidden Iceland (1)

Volcanic Eruption in Iceland: The lead up

Over the past 3 weeks, locals and volcano enthusiasts around the world have been following the seismic activity, which was caused by the intrusion of a dyke, a 1-2m wide, 7km long vertical intrusion of magma into the crust.

The biggest question on everyone’s minds: will the magma make it to the surface?

That question was answered when the eruption began in Geldingadalur valley in the Fagradalsfjall hills, at 20:45 local time. This was the area that had seen the most intense earthquake activity as the dyke was intruded. The last time this particular area of Reykjanes had an eruption was over 6,000 years ago, and prior to the onset of the earthquakes 3 weeks previously, almost nobody would have considered it likely that this area would be the site of Iceland’s next eruption. 

The Gerlingadalur Volcano by Dr. Holly Spice. Hidden Iceland (12).

Initial Observations of the Volcanic Eruption

On Saturday morning after some preliminary scientific flights over the area, it was confirmed that a fissure of around 200m in length had opened and that an effusive eruption of lava was taking place. This was the first volcanic eruption in Iceland since the Holuhraun eruption in 2014 / 15.

In this type of eruption, fluid basaltic lava is steadily erupted by fissures and/or craters and then flows away from the eruption site to form a lava field. Volcanic ash seen in the other explosive main type of Icelandic eruption is not present, however the emission of toxic gases can pose a hazard around the eruption site.

The Gerlingadalur Volcano by Dr. Holly Spice. Hidden Iceland (13).

A Visit To A Live Volcanic Eruption

By Sunday, it became clear that the authorities were not going to prevent the public from visiting the eruption site, so I decided to make the trip to Geldingadalur to see my first ever volcanic eruption in Iceland. In fact, it was my first volcanic eruption ever. As a geologist whose speciality is in the chemistry of basaltic Icelandic lava, this was a dream come true for me. Something I have been long anticipating, and of course, talking about on my tours. Seeing it with my own eyes wildly exceeded even my own very high expectations, and it is a day I will never forget for the rest of my life. 10/10 would go again. 

On the walk to the volcano, you suddenly come over the rise of a hill and are greeted with a magnificent site, a crater throwing glowing hot lava into the air! I could not imagine a more perfect version of a volcano. If you asked a small child to draw a picture of one, they would draw exactly this.

The Gerlingadalur Volcano by Dr. Holly Spice. Hidden Iceland (2).

How Does It Compare to Other Volcanic Eruptions in Iceland

The eruption at Geldingadalur is tiny compared to those produced by other Icelandic volcanoes. However it is precisely this that makes it so special and unique for those that visit it. It is possible to get so close to the crater that you can almost touch it (not recommended!). You can easily walk around the whole lava field in a few hours and view the eruption from all angles. The heat keeps you nice and warm, even in the Icelandic winter. It is extremely rare to be able to get so close to mother nature’s greatest and most fundamental process. It is truly a once-in-a-many-lifetimes experience.

Being so close, I was able to witness with my own eyes for the first time, many things I had studied in theory about eruption processes, but had never seen for myself. It brought many things I had learned at university to life.

When the lava is first erupted from the crater, it is fluid and glows orange. It then very rapidly cools in the air to form a hard brittle crust on the surface. This crust insulates the lava underneath and allows it to remain molten and continue to flow. Lava fields can cover huge distances in this way.

The Gerlingadalur Volcano by Dr. Holly Spice. Hidden Iceland (4).

Lava types of this Volcanic Eruption

Both types of basaltic lava flow are present in the lava field. These are pahoehoe and a’a lava. Pahoehoe lava has a smooth or ropey surface and is formed by slow effusion of fluid lava. A thin skin forms almost immediately on the surface which is wrinkled and bunched into a ropey texture as the molten lava continues to flow underneath. The flow is slow enough that it does not break up the crust. Pahoehoe lava flows tend to be thin (up to a few 10s of centimeters) and consist of many overlapping thin lava flows. 

A’a lava is formed where the effusion and flow rates of lava are higher. The brittle lava crust becomes fragmented and broken as lava flows beneath, resulting in a rubbly, rough appearance. As the lava front advances, the blocks are rolled along and tumble off the steep front of the lava flow and are then buried as the lava advances further. This produces a thick (up to 10 meters) lava flow, with a rubbly top and bottom. The rubbly top allows the interior of the flow to remain molten and continue to advance.

Crater Dynamics

Another interesting process to observe is the change and growth of the craters. When the volcanic eruption began on Friday night, there were 6 small craters on the line of the fissure all erupting lava. By Sunday, three of these craters had gone extinct and one large crater had taken over as the main source of lava. Two smaller craters also remained active. 

One week later, one of the small craters has grown so much that it is almost the same size as the main crater. It is likely that the two craters will merge to form one large crater. The craters grow continually as the lava that is thrown into the air lands on the sides of the crater and cools, adding to the pile. Sometimes the side of the crater partially collapses allowing lava to suddenly rush out, however it quickly builds back up again.   

Lava by Night

Not being satisfied with just one viewing of the volcano, I headed back on Tuesday evening to see it at night. If possible, this was perhaps an even more magnificent sight. The glowing lava field really comes alive in the dark and you see the lava channels in much more detail. I definitely recommend visiting in the dark if you get the chance. I could have stayed there all night watching the show. Unfortunately the area was evacuated due to dangerous levels of volcanic gas accumulating around the site as the wind dropped. On the drive home, the northern lights came out and I managed to capture them over the glow of the eruption in the distance. The Land of Ice and Fire at her finest.

A Long Lived Volcanic Eruption in Iceland?

There are several aspects of this volcanic eruption in Iceland that are cause for special attention. Firstly, the chemistry of the lava is very primitive, which means it is close in composition to the mantle that melted to form it. The lava comes straight from the mantle (the gooey, hot interior of the Earth that underlies the crust), from a depth of 15-20 km and is not stored in the crust in a magma chamber on the way to the surface.

Lava on Reykjanes is usually fairly primitive, however such primitive compositions as this have not been observed in Iceland for around 7,000 years. Lavas with similar compositions are found in shield volcanoes that were erupted soon after the glacial ice-sheets retreated. Shield volcanoes are low-angled volcanoes that resemble a Viking shield and can be active for many many years. 

In addition to the chemistry, the eruption rate of the lava has been remarkably steady since it began. Both of these observations have led specialists to suggest that this could be an eruption that lasts for many months or even many years. Perhaps then you don’t need to worry that you are missing out! If we are lucky, the eruption will continue after COVID-19 restrictions are lifted and international visitors will get a chance to see the eruption for themselves.

However, before you get too excited, I would like to caution that the eruption is barely a few weeks old, and scientists are far from being sure about this. The eruption could also die out within the coming days. Volcanoes are notorious for being continuously surprising and hard to predict. The only thing we can do is cross our fingers and wait to see how the situation plays out.

What does this mean for tourism in Iceland?

Hidden Iceland tagging in to answer some of your frequently asked questions (updated 12th February 2022)? 

Did this volcanic eruption stop airlines from flying like in the 2010 eruption?

As Holly mentioned, this is a rather small effusive volcanic eruption in Iceland, with very little ash. So, despite the fact that it is less than 30 minutes drive to the Keflavik International Airport, flight schedules were not altered at all. Therefore, in lieu of another eruption in the area, we thankfully didn’t have endure widespread flight cancellations like in the Eyjafjallajökull eruption in 2010.

Is it safe to go that close to the volcano? 

This was a truly unique volcanic eruption in Iceland. It was small and mainly lava (effusive). That means that with a great deal of monitoring and protection from the Icelandic authorities we were able to visit the volcano site while it was erupting. This didn’t mean it was safe though. Volcanic eruptions are unpredictable and can change at any moment so even with these safeguards in place there were plenty of days during that time that we chose not to go (or were forced not to go in some cases) due to increased gas levels and dangerous activity.

Despite the lack of activity these days. There is still an inherent danger. Lava still hides under the cooled crust in the lava field and crater. This means steam, cracks and heat can emanate out without visible cues. The lava field can still be dangerous. There’s no question about that, so always go with a guide if you can.

The biggest concern, at present, is the level of toxic gases. The danger of lava can be obvious and observable. A build up of gas cannot. Most of these gases cannot be detected by smell and can build up quickly, especially in a valley area like at Geldingadalur. Thankfully, the gas levels have diminished since the eruption stopped but they are by no means gone. We keep a gas monitor on us at all times, just in case.

So how do I know if it’s safe to visit that day?

A good source to check is Safetravel.is or many of the local news stations like RUV.is. Looking at the weather and notably the wind speed and direction, can give you a good indication of whether the gas will be settling in the valley, blowing towards you or being sifted away in the opposite direction. Who would have ever thought we’d be hoping for a windy day in Iceland. Thankfully, these are quite frequent in this part of Iceland.

Also, upon arrival at the trail the local authorities will quickly turn you away if the conditions have changed for the worse.

How do I get to the volcanic eruption site?

There are multiple car parks on the south side of the peninsula, around 10 minutes east of the town of Grindavik. There, you can park your car at the newly created parking lots and start the hike.

Once you have parked your car, there is a map that can be used to view the different hiking trails, though all are well marked out. You’ll also likely see many other tourists flowing back and forth on the path too on a clear day. In fact, if you are following a path and you don’t see anyone else around maybe this is a sign that you have either went the wrong way or the area is closed.

In the early days of the eruption, people were forging their own routes in all directions. Some would take anything from 5 to 12 hours over rough terrain. However, now that the eruption has ended (for now), there are easier hiking paths. Some taking as little as 15 minutes to get to the cooled lava field. Others around 1 and a half hours. It is relatively flat except for one relatively steep hill that requires full mobility of ankles and knees, akin to a stair case.

What should I bring with me?

Sadly, Search and Rescue and the police service have had to be used on numerous occasions since the eruption began (even after the eruptions stopped). This had little to do with the lava flow or gases, but rather people trying to visit the volcano unprepared. Reports of people showing up in jeans and trainers in the middle of an Icelandic winter has become common place. Others simply underestimated the difficulty and distance.

Our advice, is to consider this a full day outing regardless of how long you expect it to last. That means you should bring waterproofs, multiple layers, hats and gloves, plenty of water, snacks and lunch, fully charged headtorch, battery pack and facemask (to prevent spread of COVID-19). Even bringing blister plasters and a small first aid kit with an emergency blanket to keep you warm could be the difference between a fun hike and a painful trek.

Also alert the authorities of your travel plans, especially if you are going during the night. You can do this on Safetravel.

Will Hidden Iceland be running tours to the volcano?

Since we first opened our doors, we have always been excited by the Reykjanes peninsula and running tours there. So now, all we’ve done is add in the viewpoint of the volcano alongside the Lava Tunnel and other Reykjanes sights. Check out our tour here.

However, if there’s no availability you can get in touch with us at info@hiddeniceland.is or submit a private tour form and we can arrange something specific for you. Planning a private trip to the volcano is something that we will take care and caution in planning. Only once we have confirmation from the Icelandic Authorities on any given day will we go ahead with the visit.

We are well versed in wilderness terrain, glaciers, ice caves, weather exposure and hold a comprehensive safety management plan. Not to mention, proud holders of the Vakinn Quality and Environmental Certificate. Now our safety management plan must include volcanic eruptions too. Assessing and mitigating risk is our top priority for any trip but with careful planning we believe we can visit the volcano safely, under direction of the Icelandic Authorities. However, please bear in mind that there will always be risk, like many of our tours, when entering an unknown wilderness terrain.


If you are suitably inspired to visit this active part of the country then you can book Hidden Iceland’s small group tour of Reykjanes, Volcano and the Lava Tunnel. Or if you prefer a private tour so that you can include a trip to the volcano itself then you can simply get in touch and we’ll plan something special together. Oh, and make sure to ask for Holly as your guide!

See you there!

Dr. Holly Spice. Our Hidden Iceland glacier guide. About Us.

Hi, I’m Holly, geologist and glacier guide at Hidden Iceland. I have a PhD during which I studied the geochemistry of Icelandic basaltic lavas. When on tour, I love to teach people about volcanoes and geology! I am also a passionate climber and outdoor enthusiast.

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