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Astrum Space

Iceland's 1000-Year Lava Cycle Is Back | Captains Speaking

03 Feb 2026

Transcription

Chapter 1: What geological events are currently affecting Iceland?

1.01 - 31.291 James Stewart

Iceland is on fire. With earthquake swarms, volcanic eruptions, and lava fountains spewing hundreds of meters into the air, this tiny country is experiencing volcanic activity on a staggering scale. It isn't the first time and it certainly won't be the last. This is the awakening of a thousand year cycle. A rhythm that last transformed the landscape when Vikings walked these shores.

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32.012 - 55.589 James Stewart

And this is no blip on the radar. It's a geological marathon. The activity we're seeing today could last for two to 400 years. But this time will be different. This isn't the Viking era. Today, Iceland is a modern nation of geologists and engineers who aren't going to take this lava invasion lying down.

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56.51 - 77.815 James Stewart

As the ground tears apart beneath their feet, they're attempting the impossible, to out-engineer a continent pulling itself in two. So, can a modern society survive for centuries of fiery chaos? We're going to find out. I'm James Stewart and you're watching Astrum Earth.

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78.376 - 107.42 James Stewart

Join me as we explore the youngest land on the planet, delving into the ancient cycles responsible for carving out this mythical anomaly of fire and ice, geological patterns that have left Iceland facing the ultimate test, survival. Iceland is unique. Not only is fermented shark considered a delicacy, but geologically there's nowhere quite like it.

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108.602 - 130.877 James Stewart

It sits astride the Mid-Atlantic Ridge, a divergent boundary where the North American and Eurasian plates pull apart at a rate of around two centimetres a year. That's roughly, by the way, the same speed your fingernails grow. As the plates separate, magma rises to fill the gaps, cools into basalt and forms new crust.

131.438 - 134.903 James Stewart

And I know what you're thinking, there's nothing particularly unusual about that.

Chapter 2: What is the significance of Iceland's 1000-year lava cycle?

135.704 - 161.589 James Stewart

But over millions of years, this process has built the longest mountain range on Earth, running down the centre of the Atlantic Ocean. Almost all 16,000 kilometres lies two to three kilometres beneath the waves. That is, until you reach Iceland. Here, land pokes its head above the surface. Why? Well, Iceland isn't just on a tectonic plate boundary.

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162.691 - 179.751 James Stewart

Here, the Mid-Atlantic Ridge intersects another geological phenomenon, a mantle hotspot. These are best known for creating island chains such as Hawaii, the Galapagos and the Canary Islands, all of which I might add lie in the middle of tectonic plates, not at the edge.

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180.733 - 203.817 James Stewart

The hotspot under Iceland instead creates the geological equivalent of a pressure cooker left on high for millions of years, turning an already active boundary into something far more volatile. producing a third of all the lava that's erupted onto Earth's surface in the last 500 years, which is not bad for a country smaller than England.

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204.438 - 214.753 James Stewart

Now, mantle hotspots are somewhat of an enigma, which is sort of a nice way of saying that scientists don't exactly know what causes them. Actually, let me know in the comments below if you'd like to see a video on that another time.

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215.274 - 234.542 James Stewart

But for now, what we need to know is that they are driven by columns of unusually hot, buoyant rock rising from deep within the Earth and pushing up through the mantle, and that they can last for tens of millions of years. Now, the important thing to note here is that these hot spots can raise mantle temperatures by as much as 200 degrees Celsius.

235.123 - 259.356 James Stewart

And in doing so, the drop in pressure causes hot, solid rock to melt into magma. The result is an unusually thick crust, up to 40 kilometres compared to typically 7 kilometres, and enough buoyancy to lift the ridge out of the ocean. Et voila, an island, or in this case, an Iceland. This is the only inhabited mid-ocean ridge on Earth.

260.057 - 283.876 James Stewart

In fact, visit Thinkvitlia National Park and you can literally stand in the separation zone between two continents. But it's what's inside that ridge that's problematic. We often talk about tectonics in the past tense, but in this case the problem is present, very present. Iceland is a mere teenager in geological terms.

284.396 - 307.557 James Stewart

The oldest rocks found in the west fjords and the eastern fjords are just 16 to 18 million years old, which is basically yesterday compared to continental Europe's half-billion-year-old crusts. And if you thought that was impressive, well, wait for this. When you move south, the land gets even younger still. It is only 3 to 7 million years old in places like the Reykjanes Peninsula.

307.957 - 331.223 James Stewart

And remember that name, it's somewhere we're going to come back to. Now, just off the south coast is the youngest land on the planet. In the 1960s, the island of Surtsey erupted into existence from beneath the sea. The island is a pristine natural laboratory, allowing scientists a rare chance to study an island from birth, really.

Chapter 3: How does Iceland's unique geology contribute to volcanic activity?

610.054 - 624.515 Unknown

A surreal glowing curtain of lava, 180 metres long, founted into the air before flowing into a sheltered valley. It was the first eruption on the Reykjanes Peninsula in eight centuries.

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624.995 - 653.569 James Stewart

I said I'd come back to this place, and it went on for nearly six months before suddenly stopping. But that was not a return to dormancy. That was just the start. Further eruptions followed in 2022, and again in 2023. Then the activity began to migrate, shifting a few kilometres southwest to Svart Sengi, along the Sundsnuknigal crater row. It was closing in fast.

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655.152 - 677.189 James Stewart

On the 10th of November 2023, the decision was taken to evacuate the town of Grintovik, home to 3,700 people. The telltale seismic swarm showed that a major magma intrusion was propagating beneath the town. Days after the evacuation, fissures opened, destroying homes and damaging infrastructure.

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678.351 - 707.707 James Stewart

It was described as Iceland's most severe natural disaster in 51 years, and Grindavik remains largely uninhabited today. For geologists, this was the final confirmation needed that a long, quiet volcanic system had awoken. The starting pistol for a centuries-long eruptive cycle. But how do they know this is only the beginning? By bringing Viking sagas into the satellite age.

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708.328 - 728.866 James Stewart

This, my friends, has happened before. When you think of what Icelanders have to deal with on a daily basis, i.e. actual lava, it makes me realise I've got it pretty easy here in my very boring village in the UK. And I've got a bit complacent over the years, truth be told. I mean, there's literally a pub and a pond here. That's it.

729.227 - 748.457 James Stewart

My biggest worry right now is why did I throw my Pokemon cards away in 1998? And all that nonchalantness has given strangers a free ticket into my house without me realising. It's kind of crazy when you think about it. We do everything we can to protect our families physically, don't we? We buy life insurance, we lock the doors at night, we install security cameras.

748.477 - 768.914 James Stewart

I mean, I've got about seven of the things here. I'm an Alfred away from a Bruce Wayne-style surveillance operation. But the biggest vulnerability might be the digital map leading to the mother load inside the house, my data. That's why I'm using Delete Me. It's proactively removes my home address, phone number and family details from the internet.

769.415 - 792.263 James Stewart

So don't wait for a scare to happen, be proactive. Remove the digital breadcrumbs that lead the bad guys to your front door. why not treat yourself to a digital detox this year and join Delete.me. You can get 20% off with my link, joindelete.me.com slash astromearth and use code astromearth at checkout. Thanks to Delete.me for sponsoring this video.

792.283 - 819.872 James Stewart

The link is in the description if you want your digital life a bit more private as we head back to the video. The Norse Vikings first settled in Iceland in 874 AD, and lucky for us in this instance, were impeccable record keepers. Their annals and sagas describe fire coming out of the sea and darkness during daytime in the Reykjanes area between 1210 and 1240.

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