Image credit: Ximonic (Simo Räsänen) (Own work) [CC BY-SA 3.0]

Image credit: Ximonic (Simo Räsänen) (Own work) [CC BY-SA 3.0]

What makes Iceland so warm despite its high latitude? What powers everything from glaciers to geysers? How are the aurora connected to volcanoes? I discuss these questions and more in today’s Ask a Spaceman! A very special edition recorded in Vik, Iceland, where I gave a special talk on the forces fighting for balance underneath and above the island.

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Hosted by Paul M. Sutter, astrophysicist at The Ohio State University, Chief Scientist at COSI Science Center, and the one and only Agent to the Stars (http://www.pmsutter.com).

 

EPISODE TRANSCRIPTION (AUTO-GENERATED)

This is obviously not going to be a normal episode of Ask a Spaceman. I gave a talk while I was in Iceland with the AstroTorus and I wasn't planning on giving a talk. I was just gonna do an open ended q and a for a while. It was gonna be lots of fun and spontaneous and sparkling and bubbly and all the usual science and goodness. And it turned out we got completely snowed in where we are locked into our hotel.

All the roads were closed for two and a half days. And so I had to come up with some extra content. So the next episode of Ask a Spaceman is gonna be that q and a. This episode is gonna be a talk I made up on the spot about one hour before I gave it. And the subject of the talk is the title of the episode, Why is Iceland so Warm?

And I had this realization a couple days into the trip as we're looking at all the beautiful vistas and the aurora and if you didn't go on the trip, you really missed it. It was pretty awesome. I had an epiphany. I had one of those like, a mild a mild eureka moment where a lot of things clicked into place. That a lot of the things that I were seeing, the sights and the sounds and the the just the visual treat of that country.

So many things clicked into place surrounding a common theme and I'm gonna explore that theme in the talk. But the other important thing that I realized is that you need to go to patreon.com/pmstarter because I didn't mention it during the talk. So here is the pitch. Patreon is how you keep this show going and special thanks to Robert r, Justin g, Matthew k, Kevin o, Justin r, Chris c and Helga b for all your generous contributions at patreon.com/pmsutter. And this is Ask a Spaceman.

You can always send questions to askaspaceman@gmail.com. Go to askaspaceman.com. Use hashtag askaspaceman on Twitter and Facebook and even Instagram and you can have your questions answered this time. This is a question that I asked myself. So without further ado, here's the recording of my talk.

Now in the talk sorry, just kidding. There's gonna be a little bit more ado. In the talk, I mentioned some visuals. I had up some pictures I'm showing. If you wanna see that, I did my best to describe it as I'm talking to serve you, the podcast listener.

But if you wanna see it, go to youtube.com/paulmsetter. I put the videos up too. And there's the talk, so you can see me waving my hands around, walking around on stage, all the good stuff and the pictures which are what you're really after. Now, for real, without further ado, here's the talk. To get started, I get a lot of questions.

I got a lot of a lot of people curious, especially from kids, of of how do you how do you think as a physicist? If you're trained as a physicist, if you work as a physicist, how do you approach the world? Like, as I'm walking through the the amazing vistas that Iceland has to offer, as we're all doing it, we all have our individual thoughts and recollections and and we're noticing things. And what do I notice as a physicist? How am I thinking about what Iceland has to present to me?

So to think like a physicist, there are three easy steps that you can all follow. Step number one, to think like a physicist, is to ask simple questions. All of physics, through hundreds of years, is all motivated by asking incredibly simple questions of nature. How does this work? How heavy is that thing over there?

Why does this do that? Very simple questions. Not easy questions, but they're very simple questions. So when we're confronted with the situation, when we see something, we ask the most simplest question we can, and we start from there. And then to start building our answer, we start at the beginning.

We go to what we call first principles. What is the simplest thing you can say? What is the absolute starting assumption, the most raw observation you can make to build your answer? And you go from there. So, every physics paper starts with an introduction, going back, building the case until you get to your advancement.

Every conversation, every problem that we try to solve starts from first principles, from the beginning. So ask simple questions, start from the beginning to build your case, and then once you have your answer, once you've built your case, now that you understand a physical system, look for the connections. Because one of the most wonderful things about physics is that it's universal. The same physics that apply here on Earth apply across the universe. So if you can understand something in one situation, if you understand the fundamental forces and energies involved in one situation, you can apply it.

You can copy that solution all across the universe. Now, I'll give you some examples of that. And so my my simple question, when I'm here standing in Iceland, my very simple question that I'm gonna start from today is why is Iceland so warm? Now, that may seem ridiculous because we're locked inside from a blizzard. But if you remember, like, yesterday, it was kinda nice.

And when you flew in, it was kind of nice. And it's much, much more pleasant here in Iceland than it has any right to be. Right? Because we're, yo, here's an image. Here's a picture of Iceland in the summer.

It it don't look outside. Look at the picture. This looks glorious. But, we're here. We're just South Of The Arctic Circle.

Low Island, just South Of The Arctic Circle. Look at what else is on the Arctic Circle this far north. Northern Canada, the middle of Greenland, Northern Alaska, Northern Siberia, frozen tundra wastelands. And yet, Iceland is abundant with life, is capable of supporting large human populations, a major city, bunch of settlements, industry. Why?

Why? I mean, we're so cold. I took this picture in Reykjavik A Couple Days ago. This is high noon two days ago with the sun barely peaking above the buildings here in February. It ought to be extremely cold all the time.

We ought to not even be able to be here this far north. Why is Iceland so warm? Well, in this case, the reason we should be cold is that the sun is at a very very low angle. We're so high up in latitude that the sun doesn't shine on us very well. We're all the way up north, so we get really, really oblique angle from the sun.

So that's a little bit of sunlight spread over a lot of land and there's not a lot of heating going on. But, first principles. Where can we start? How can we begin to explain this mystery of why Iceland is so warm? Well, it's cold up here.

It ought to be incredibly cold up here. But it's warm at the Equator. Right? The sun is constantly shining directly down onto the Equator and onto the tropics. Right?

The jungles of the world are incredibly hot. So it's hot down there. Hey. And we know something. We know some physics.

We know that if you have a bunch of air and one side is hot and the other side is cold, the hot stuff is gonna move. Temperature wants to equalize. Temperatures want to even out. So in the Earth in the Earth, the heat from the Equator that's constantly warm from the sun wants to go to the poles. It wants to equalize all of Earth's weather.

All of Earth's weather is the Earth's attempt to equalize itself from the uneven heating of the sun. Some parts of the earth get hotter than others, and it's trying to equalize it all out. Now, if the earth were perfectly static, perfectly flat, not spinning at all, we would have straight line winds coming from the South into the North, from the Equator to the North and from the Equator to South. Straight. But the Earth is spinning.

Right? Right? Yeah. Yeah. Yeah.

Okay. Okay. Just checking. Just checking. We're all on the same page.

We all have the same fundamental principles coming into this problem. The Earth is spinning. So the straight lines become curved in a spinning system. Instead of straight lines coming from the Equator to the North, we get these massive what we call gyres, these massive circulation systems, these circles of water and air going around the globe. And so we have warm air coming from the Equator, coming up the coast to Cuba, the Gulf Coast, then shooting across the North Atlantic, going into Europe, and heading into Iceland, bringing warm air and warm water up to regions that would otherwise be frozen wastelands.

This is what enables Iceland to be so warm. Here's a more detailed picture you can see. We have a current coming off of Africa, goes into the Gulf, loop Gulf, loops around Florida, shoots across the Atlantic, that's the jets the Gulf Stream right there, coming up to Northern Europe in Iceland. So the coasts of Iceland are able to maintain a warmer temperature because they're getting a constant delivery of warm water and warm air all the time coming from the Equator. So it's a relatively special place.

If you put Iceland somewhere else, this exact same massive land somewhere else, it wouldn't get those benefits. That's why Greenland is so much colder than Iceland because that Gulf Stream misses it, even though it's the exact same latitude. So is in so much of the weather effects we see here are driven by this gulf current, this warm air coming from the Equator. When you when this Gulf air hits somewhere like Ireland, it gets you get a lot of rain in England, Northern Europe, and Ireland. When it comes to Iceland, it comes in the form of snow because we are farther up north.

So there's an incredible amount of snow constantly dumped onto this island. And the snow packs, layer upon layer upon layer, incredible pressure pushes down. And if there's any downward slope anywhere, that snowpack is slowly going to ooze down. A river of ice that we call a glacier. Did all of us see the Glacial Lagoon?

Yes. Yesterday? Yeah. This was a region where when these massive rivers of ice was finally meeting the sea and then fragmenting and breaking apart and melting back into the ocean. But it's all driven.

That moisture that you saw entering the ocean in that bay was generated in the Equator and carried via the Gulf Stream northwards, then dropped down onto the land mass of Iceland, probably thousands of years ago. And then over the centuries pushed down until it finally meets the the sea again and the circle is complete. So is that it? Is that the total answer to the mystery of why Iceland is so warm? Well, there's another feature of Iceland that's been pointed out to us a lot and that's the volcanoes.

Right? But volcanoes are underground. They don't care about gulf streams and precipitation and snowpack. They're just really hot on their own. It's heat coming from the Earth itself.

There's another reason why Iceland is so warm. And in fact, if you look at a map of Iceland, it is lousy with volcanoes. There's this strip of volcanoes running across the entire island and of active fields. And we know how volcanoes work. We know where the heat comes from to power a volcano.

It's not from the sun, but it's from the core of the Earth itself. The core, the interior of the Earth is incredibly hot, molten. This heat doesn't come from the sun. It comes from two sources. There's two reasons why the interior of the Earth is so hot.

One is its leftover heat from the formation of the Earth itself. Four and a half billion years ago, there was no Earth. There was just a big ball of gas and dust swirling around the young proto sun, and it collapsed. It congealed, glued itself together to become a planet. When you have a big giant cloud of gas and you squeeze it down, it heats up.

That generates heat. It became a very hot thing. And then slowly over eons, it can cool off. But it's very inefficient. It's very slow.

So there's still leftover heat from an Earth that formed four and a half billion years ago that's still cooling off, still keeping the interior hot. And there's another source of heat. That when the Earth was formed out of the protostellar disk that formed our own solar system, there was oxygen, silicon, carbon, some water, you know, all the usual stuff. There was also radioactive elements seeded, dusted throughout that young solar system, uranium, plutonium, radioactive potassium. This These radioactive elements decay.

Natural decay. When a radioactive element decays, it releases some heat. So about half of the Earth's heat, interior heat, is due to radioactive decay. So when you see a volcano, when you see a volcano erupt or you see a lava field or you see these these massive piles of rocks that are deposited all around the shore from these massive titanic explosions that is powered in part by the formation of the Earth itself four and a half billion years ago, in part from countless radioactive decay events happening within the Earth right now. That is a massive source of energy.

That is a massive source of power, and it's literally right underneath our feet. We are on the surface of the Earth. We are practically exposed to space. It's like right there. Like 60 miles, a hundred kilometers away is pure vacuum.

We're on the edge. Most of the Earth is incredibly hot. And there are places where this heat is able to come all the way up to the crust where we live, like in Iceland. And it can power things like volcanoes, where you can have a chamber of magma that keeps spewing itself out onto the surface and building ever, ever higher structures to become a volcano. It can generate hot springs and geysers.

When the ground directly underneath this is so hot that any water, any melting snow or rainwater that makes its way through the ground touches hot rocks, magma pools, and escapes as steam or boiling water comes back right back up to the surface. It's exposed. This energy of the formation of the Earth itself, this energy from the constant nuclear decay happening inside the Earth are exposed to the surface in a few rare places like here in Iceland. And it powers tectonic plates. The shifting of continents over time is all powered by this interior heat of the Earth.

And this is one of the places, Iceland is one of the places where these tectonic features, where these cracks in the crust of the Earth itself are exposed. And I like to think of plate tectonics. I know it's it's kind of hard to imagine. I I personally have a hard time imagining tectonic plates like giant pieces of continent shifting around. So instead, I like to build an analogy to help me think about it, to help me visualize this particular map.

If you saw in the Glacial Bay the other day, you saw icebergs. Right? You saw what could have been a giant featureless sheet of ice, but it was broken into pieces. And these pieces of ice were less dense than the water underneath it. So they floated.

And they were constantly grinding up against each other, bumping, rebounding. Sometimes one would slip under another one, or they would come together and crash and build a little ridge. You can see that actively in the in the bay over the course of minutes or hours. Well, take the glacial bay with its ice, its fragmented ice sitting on top of the water, and make it spherical where there's water on the inside and then a shell of ice broken into a bunch of pieces. And all these pieces of ice grind and scrape against each other and go underneath each other and build mountains.

Now, replace the liquid water with liquid rock and replace the solid water with solid rock. And it's the exact same physics operating at different time scales and different temperatures, but it's the exact same physical process. Continents riding along, grinding against each other, and splitting apart, like in the Mid Atlantic Ridge. This is a seam in the crust of the Earth where new continents are being born every single day. New material is upwelling from the interior, powered by the heat of the Earth and pushing outwards.

In this seam, this crack in the Earth runs all the way down the Atlantic and then down all the way down between South America and Africa, and it's exposed above the ocean in one spot where we are now. And there's a rift valley even in Iceland where you can see this happening, where there's this massive ridge of new material that was thrust up to the surface and then slowly being split apart as those two continents push against each other and drive the Americas and Europe farther apart from each other every day. This same heat source, the intense energies in the core of the Earth, power something else. The lights in this room. Geothermal power is probably the easiest way to generate power, you know, second only to like waterfalls.

You just drill a big hole and then it's really hot down there. You pour some water down and it comes right back out as steam and you got a lot of steam. You use that to drive a turbine, generate some electricity and then you got all this extra water that's now a little bit cooler and then you dump it like way out there. That's it. That's it.

The simplest design for a geothermal power plant. Energy basically for free. Tapping into this billion year old process of the Earth slowly losing heat over the course of billions of years, tapping just a little bit bit of it to keep the lights on. This same energy, this same energy source, our hot molten core, also powers a strong magnetic field. Earth is so unique amongst the planets in the solar system.

Mercury, incredibly tiny magnetic field, barely there. Venus, nothing. Mars, nothing. Earth, we have a pretty strong magnetic field. We have a strong magnetic field because we have a molten core.

That molten core can act as a dynamo. It can generate a magnetic field that looks a lot like a bar magnet, like a north and a south. This magnetic field acts as a literal force field around our planet. And there's one particular spot. There's something else interesting here about Iceland, where the forces of the Earth, the heat in our core left over from our formation meet the forces of the Sun.

Not just in the case of, oh, there's a volcano here and then there's also a blizzard coming down the Gulf Stream, but in the case of the aurora because the sun is constantly emitting a stream of high energy particles filling out the solar system. These high energy particles slam into our own magnetic field. Some of them get caught by our magnetic field and get trapped and are forced to follow corkscrew winding paths around the planet and get dumped into the North And South Poles. And where those high energy particles meet the atmosphere, we get the aurora. The aurora is a visible manifestation of the competing forces of our own Earth's energy, the heat left over from our formation that's able to power this giant magnetic field, and the power of the sun itself.

Now, I know some of us were out, got to see the aurora, we took some kind of okay pictures. I didn't wanna pick a winner, so instead, I I took a picture from space, from the International Space Station, which is probably gonna beat anything we can get. But this shows the beauty of these aurora, of this complex interplay between our magnetic field and the solar wind. And as a physicist, it's always fun to think about the ultimate source of these. Where is the energy coming from?

Where are the forces coming from? In one case, it's coming from nuclear reactions happening deep in the sun, and in the other case, it's coming from nuclear reactions deep in our own Earth's core. They're manifesting in different ways and they're interacting right here. So Iceland is warm, kind of warm. Yeah.

Because of the energy of the Earth itself and the energy of the sun. But now let's make some connections. We've seen so many amazing things here in Iceland. Right? We've seen glaciers.

We've seen kind of volcanoes in the distance. We've seen aurora. Can we apply the physics that we've learned here on Earth anywhere else in the solar system? Well, let me show you some pictures. Here's the North Polar Cap of Mars.

What do you see? Ice. Do you see ice? There are glaciers there. There are glaciers.

There are rivers of ice on Mars. Primarily water ice, but also because the temperatures are so cold, frozen carbon dioxide, dry ice. But the exact same physics that drives a glacier on Earth drives a glacier on Mars. Here's the Mariner Valley, the largest canyon on Mars. We're not 100% sure what formed it, but we're pretty sure it's a rift valley.

The same rift valley that you can visit here in Iceland. The same rift valley that runs down the spine of the Atlantic Ocean. The exact same kinds of physics of massive pieces of plates of structures ripping themselves apart over geologic timescales tore this massive crack in the side of Mars. The Mariner Valley, by the way, is the length of The United States. It's the largest canyon in the solar system.

Here's another system. Here's a picture of Jupiter. What do you see? Aurora. Jupiter has an incredibly strong magnetic field.

The solar wind meets the magnetic field of Jupiter. Exact same physics, exact same plan game played all across the solar system. Massive, beautiful aurora that we can see. This is from the Hubble Space Telescope, by the way. Here's the South Pole of Jupiter.

What do you see? This is all gas, mostly hydrogen, helium, a little bit of ammonia, sulfur. What kind of formations do you see in the cloud tops? Flows? Circles, spirals, gyres.

Jupiter is spinning. Jupiter is unevenly heated. Exact same physics. Exact same game played over again. Circulation patterns.

Here's a moon of Jupiter called Io. That at the top, is a volcano erupting on the surface of Io. Io is heated by a different mechanism than the Earth is because it's very small. It cooled off a long time ago, but it orbits around Jupiter, this massive planet. It's stretched and squeezed from the changing gravity in its environment, heats up its core.

Be the exact same thing. You have a hot core, you have a cold surface. Magma volcanoes building themselves. The most volcanically active planet world in the solar system. Number two is Earth.

Here's another moon of Jupiter called Europa. Europa is covered in a thick sheet of ice about a hundred kilometers thick. What do you see on the surface of Europa? Cracks, fissures, tectonics. Tectonics, but not of of rock and magma, but tectonics of ice.

Underneath this shell of ice is a liquid water ocean that spans the entire globe of Europa. Liquid water. Riding on top of that is a hundred kilometer thick layer of ice that is broken into a bunch of pieces that constantly rub and shift against each other. Exact same game, just at colder temperatures with different materials, but the physics are the same. This is a volcano on Europa.

But it's not a volcano of rock. It's a volcano of ice. The temperatures of Europa are colder than here on Earth. So it's not molten rock. It's not mountain made of solid rock with molten rock underneath it that squirts out.

It's a mountain of solid ice with liquid ice, a k a water, in the center that sometimes squirts out. This is called a cryovolcano, a cold volcano. Couple years ago, New Horizons flew by Pluto. This outermost world in our solar system, very distant. First time ever we got a high resolution image of its surface.

And you see this famous heart shaped feature. Here's a zoom in and the colors are enhanced to show the contrast of the detail. It's glaciers. A vast glacier, but not of water, not of carbon dioxide, but of nitrogen. Frozen nitrogen.

And it's not frozen solid though. It's not a solid block. Like a glacier is not 100% solid. It moves, it oozes over time. These giant nitrogen glaciers are oozing, shifting.

Water ice floats on top of nitrogen ice. So these nitrogen glaciers actually carry mountain sized boulders of water ice. The same way we saw in the glacial bay, the glacier carrying rocks and depositing rocks, depositing ice on the beach. Happening again, but at far colder temperatures. What's keeping Pluto warm?

Actually, we don't know. That's a big mystery. We don't know why Pluto is so warm. So it's the follow-up, the question of why is Iceland so warm? We were pretty comfortable with that answer.

Why is Pluto so warm? We're not too sure about that, but this is why physicists ask simple questions because you can ask the same simple question over and over and over again, and nature is always going to surprise you. Thank you.

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