0:00:02 > 0:00:05Iceland, the clue is in the name. It's a bit chilly.
0:00:05 > 0:00:08Chilly? It's absolutely freezing.
0:00:08 > 0:00:10100,000 square kilometres
0:00:10 > 0:00:13of snowy rock close to the Arctic Circle.
0:00:14 > 0:00:17Whichever way you look at it, Iceland is icy,
0:00:17 > 0:00:19but how do you explain this?
0:00:19 > 0:00:22Wow! It's boiling Earth!
0:00:23 > 0:00:27Get ready to feel the heat on today's Fierce Earth.
0:00:27 > 0:00:29'We're exploring Iceland,
0:00:29 > 0:00:31'the country created by volcanoes.'
0:00:31 > 0:00:33Wish me luck.
0:00:34 > 0:00:38Leah is plunging over a kilometre down into Britain's deepest mine.
0:00:38 > 0:00:41The heat is overwhelming.
0:00:41 > 0:00:44And Leo is taming the power of the geyser.
0:00:44 > 0:00:45Let's do it.
0:00:45 > 0:00:48Hang on for the ride, it's going to get hot.
0:00:50 > 0:00:52What happens when the ground shakes,
0:00:52 > 0:00:55the seas rise up
0:00:55 > 0:00:57and the air tears itself apart?
0:00:57 > 0:00:59The Fierce Earth team move in,
0:00:59 > 0:01:02taking on the most powerful forces on the planet.
0:01:18 > 0:01:20Get ready for Fierce Earth.
0:01:20 > 0:01:22The Earth and how to survive it.
0:01:26 > 0:01:30The fierce heat from deep within our boiling planet Earth
0:01:30 > 0:01:34creates incredible sights for us to enjoy up here on the surface.
0:01:35 > 0:01:38Geysers, volcanoes,
0:01:38 > 0:01:41spectacular lava flows.
0:01:41 > 0:01:45These volcanic wonders can be found dotted all over the world,
0:01:45 > 0:01:48but there's one very special country where you can see them
0:01:48 > 0:01:50all in one place - Iceland.
0:01:56 > 0:01:57A geyser.
0:01:57 > 0:01:59Boiling water and steam blasted
0:01:59 > 0:02:02straight from the depths of the Earth.
0:02:03 > 0:02:05This one is called Strokkur
0:02:05 > 0:02:08and close by is Geysir, which in Icelandic means to 'gush'.
0:02:08 > 0:02:10It doesn't erupt any more,
0:02:10 > 0:02:14but it's given its name to the rest of the geysers across the planet.
0:02:16 > 0:02:19And it's the planet that gives geysers their power,
0:02:19 > 0:02:20just look at this thermal camera.
0:02:20 > 0:02:22I'm picking up nearly boiling
0:02:22 > 0:02:23temperatures at the surface.
0:02:23 > 0:02:25That means that, beneath our feet,
0:02:25 > 0:02:28a few miles, the Earth is a raging furnace,
0:02:28 > 0:02:31a nuclear power reactor generating heat.
0:02:31 > 0:02:34Now, it's hard to imagine that when you're standing in the cold
0:02:34 > 0:02:37and the snow of Iceland, unless you make a snowball.
0:02:43 > 0:02:47Imagine this rock is the core at the very centre of our Earth.
0:02:47 > 0:02:52Now, the solid part in the middle is over 5,000 degrees Celsius.
0:02:52 > 0:02:55That's about as hot as the surface of the sun.
0:02:58 > 0:03:00Most of the rest of the Earth,
0:03:00 > 0:03:03nearly 85% by volume,
0:03:03 > 0:03:05is made up of the mantle,
0:03:05 > 0:03:07and that's going to be represented
0:03:07 > 0:03:08by this red snow I've dyed here.
0:03:08 > 0:03:11The mantle isn't as hot as the core,
0:03:11 > 0:03:12but it's still a searing heat over
0:03:12 > 0:03:14thousands of degrees in places.
0:03:14 > 0:03:18A thick, toffee-like hot rock that moves very slowly.
0:03:18 > 0:03:20So there we have it,
0:03:20 > 0:03:21there's our Earth.
0:03:21 > 0:03:23But almost all of it,
0:03:23 > 0:03:25apart from one tiny thin layer
0:03:25 > 0:03:27on the top.
0:03:27 > 0:03:29The Earth's outer layer is incredibly thin
0:03:29 > 0:03:31in relation to the rest of the planet,
0:03:31 > 0:03:33much thinner than I can roll in the snow.
0:03:33 > 0:03:36Imagine a postage stamp stuck on a football.
0:03:36 > 0:03:39And it's this thin top layer, where we live,
0:03:39 > 0:03:43that's cold, sometimes freezing,
0:03:43 > 0:03:46but just beneath the surface...
0:03:47 > 0:03:49..it's boiling.
0:03:50 > 0:03:51Wow!
0:03:52 > 0:03:58Geysers are spectacular proof that there's heat just beneath our feet.
0:04:00 > 0:04:02Geysers are formed when water,
0:04:02 > 0:04:04boiled by the heat from within the Earth,
0:04:04 > 0:04:06bubbles up through cracks
0:04:06 > 0:04:07towards the surface.
0:04:07 > 0:04:09If cold water is above,
0:04:09 > 0:04:12this stops the hot water escaping.
0:04:12 > 0:04:13The hot water gets stuck
0:04:13 > 0:04:16and churns around
0:04:16 > 0:04:17warming the cold water
0:04:17 > 0:04:20until finally it gets even hotter,
0:04:20 > 0:04:22flashing to steam with enough pressure
0:04:22 > 0:04:24to burst through the colder water above.
0:04:26 > 0:04:28Whoosh!
0:04:28 > 0:04:29And we have our geyser.
0:04:35 > 0:04:39And there's a reason for all this volcanic activity.
0:04:39 > 0:04:43The land round here is constantly growing -
0:04:43 > 0:04:45Iceland is alive.
0:04:46 > 0:04:49It's down to plate tectonics,
0:04:49 > 0:04:52the large-scale motion of the Earth's outer layer.
0:04:52 > 0:04:55This layer is made up of giant rocky slabs called plates
0:04:55 > 0:04:58that float on top of the underlying hot rock,
0:04:58 > 0:05:00like a huge jigsaw puzzle.
0:05:00 > 0:05:03Iceland is an island in the Atlantic Ocean,
0:05:03 > 0:05:05slap-bang where two tectonic plates meet -
0:05:05 > 0:05:08the American and the Eurasian.
0:05:08 > 0:05:10These plates are moving apart
0:05:10 > 0:05:12at an incredibly slow rate,
0:05:12 > 0:05:14about 2.5 cm a year,
0:05:14 > 0:05:17but that's enough to open up tears in the Earth
0:05:17 > 0:05:20that let the hot mantle seep out as magma.
0:05:20 > 0:05:23The result is an incredible landscape with volcanoes,
0:05:23 > 0:05:25geysers and lava flows
0:05:25 > 0:05:28powered by the hot volcanic rock,
0:05:28 > 0:05:30formed from an otherwise freezing country.
0:05:32 > 0:05:38And it's the mix of fire and ice that makes Iceland unique.
0:05:38 > 0:05:42And what's more incredible is that you can see the very point
0:05:42 > 0:05:47at which two giant tectonic plates tear themselves apart.
0:05:47 > 0:05:49With Europe over this side
0:05:49 > 0:05:52and America over here.
0:05:52 > 0:05:55But the very point at which those plates touch,
0:05:55 > 0:05:57one slight problem,
0:05:57 > 0:06:00it's at the bottom of that icy lake.
0:06:00 > 0:06:06This is Silfra, a lake formed from melting glacier water flowing into
0:06:06 > 0:06:08the actual tear between the two tectonic plates.
0:06:08 > 0:06:12The water in Silfra is just above freezing.
0:06:12 > 0:06:16I wouldn't last more than a couple of minutes in a standard wetsuit,
0:06:16 > 0:06:18so I'm wearing a dry suit
0:06:18 > 0:06:22that will keep as much water as possible away from my body.
0:06:22 > 0:06:27'Silfra is beautiful, but diving here is serious business.'
0:06:27 > 0:06:28Whoa, he-he.
0:06:29 > 0:06:31This is quite cold.
0:06:31 > 0:06:34A constant two degrees Celsius.
0:06:34 > 0:06:37The water is so fresh,
0:06:37 > 0:06:41you can drink it straight from the glacier.
0:06:41 > 0:06:42Wish me luck.
0:06:43 > 0:06:46You should never normally drink straight from lakes,
0:06:46 > 0:06:49but the water in Silfra is crystal-clear
0:06:49 > 0:06:52and the sights hidden below the surface are spectacular.
0:07:02 > 0:07:05They call this area the Silver Cathedral.
0:07:06 > 0:07:09All around me are the rocks left behind
0:07:09 > 0:07:12as the two giant tectonic plates pull apart.
0:07:13 > 0:07:17Look carefully and you can see that these rippled boulders
0:07:17 > 0:07:19were once red-hot flowing lava.
0:07:28 > 0:07:31And here's what I've come for,
0:07:31 > 0:07:34the point where you can actually touch
0:07:34 > 0:07:37two continental plates at the same time.
0:07:46 > 0:07:53I can put my hand on the Eurasian plate and then the American plate.
0:07:57 > 0:07:59Eurasian,
0:07:59 > 0:08:01American,
0:08:01 > 0:08:02what a thrill.
0:08:02 > 0:08:07I can feel the power of the planet coursing through my fingers,
0:08:07 > 0:08:08even with mittens on.
0:08:15 > 0:08:18Wow! That's amazing.
0:08:18 > 0:08:21I've actually touched two different continental plates.
0:08:21 > 0:08:25With the Earth splitting apart like that,
0:08:25 > 0:08:28no wonder Iceland is the home of boiling Earth.
0:08:37 > 0:08:39Later in Fierce Earth,
0:08:39 > 0:08:42Clare and I will be trekking deeper into Iceland's volcanic heart
0:08:42 > 0:08:43for a very special picnic.
0:08:45 > 0:08:49Back in the UK, Leo is on his own quest for adventure
0:08:49 > 0:08:51inspired by geysers.
0:08:51 > 0:08:55An ordinary day, an ordinary lake.
0:08:55 > 0:08:57No sign of the boiling Earth here,
0:08:57 > 0:09:00but have no fear, geyser lovers.
0:09:00 > 0:09:03Today, we're going to turn the power of the geyser on its head.
0:09:05 > 0:09:07Geysers can shoot thousands of gallons of water
0:09:07 > 0:09:09up to 60 metres into the air.
0:09:09 > 0:09:12The Jetovator is part geyser,
0:09:12 > 0:09:15part Jet Ski and uses high-powered jets of water
0:09:15 > 0:09:18to propel a rider over seven metres in the air
0:09:18 > 0:09:21at speeds approaching 25 mph.
0:09:21 > 0:09:25It's the nearest thing you can get to riding the boiling Earth.
0:09:25 > 0:09:27So, Mark, how does this thing work, mate?
0:09:27 > 0:09:30Well, Leo, basically, the Jet Ski, which we've got back here,
0:09:30 > 0:09:33is acting as a water pump and it pumps water through the hose
0:09:33 > 0:09:35- and kicks it back at the Jetovator. - OK.
0:09:35 > 0:09:37You've got thrust coming out in the middle bottom there.
0:09:37 > 0:09:40And then, you've got water jets coming out of these as well, right?
0:09:40 > 0:09:44Yeah, these give you stability and aid in the hard turns.
0:09:44 > 0:09:46This is going to be fun. Let's do it.
0:09:46 > 0:09:47Yeah. Let's go.
0:09:49 > 0:09:51Seems simple enough.
0:09:51 > 0:09:52What could possibly go wrong?
0:10:08 > 0:10:10This is it - the moment of truth.
0:10:11 > 0:10:14Riding the power of the geyser to the max.
0:10:19 > 0:10:21HE LAUGHS
0:10:23 > 0:10:26Miles harder than I thought it was going to be.
0:10:26 > 0:10:29Never mind. They say practice makes perfect!
0:10:29 > 0:10:30- Right, are you ready?- Yeah.
0:10:34 > 0:10:35Well, they say that...
0:10:53 > 0:10:57Taming the power of the water geyser is not going to plan.
0:10:57 > 0:10:58Time to regroup.
0:10:58 > 0:11:00Oh, that was difficult!
0:11:00 > 0:11:03That was miles harder than I thought it was going to be.
0:11:04 > 0:11:08It's like... There's a lot of power in that jet.
0:11:08 > 0:11:09But it's really subtle,
0:11:09 > 0:11:13the difference between having control and not having any control.
0:11:13 > 0:11:16I didn't feel like I had a lot of control.
0:11:16 > 0:11:17Oooh!
0:11:19 > 0:11:21This time, I take things slowly.
0:11:21 > 0:11:25Easy on the water jets, steady with the thrust.
0:11:25 > 0:11:30And suddenly, finally, I'm flying!
0:11:34 > 0:11:35Wooo-hoo!
0:11:37 > 0:11:41What a thrill. Zooming through the air on nothing but jets of water.
0:11:41 > 0:11:43I am the geezer on the geyser!
0:11:51 > 0:11:54We've already seen spectacular proof that the Earth below our feet
0:11:54 > 0:11:56can boil water.
0:11:56 > 0:11:59But exactly how far do you have to go down below the surface
0:11:59 > 0:12:01before things start heating up?
0:12:01 > 0:12:04Leah is digging for clues in North Yorkshire.
0:12:06 > 0:12:07Boulby mine, Cleveland.
0:12:07 > 0:12:11Every year, it produces over a million tonnes of the fertiliser,
0:12:11 > 0:12:15potash, as well as half a million tonnes of rock salt.
0:12:15 > 0:12:18And to get to it, you have to dig deep.
0:12:18 > 0:12:21Almost 1.5km into the Earth.
0:12:21 > 0:12:23It makes Boulby the deepest mine in the UK
0:12:23 > 0:12:25and the second deepest in Europe.
0:12:27 > 0:12:31I'm about to experience for myself how the Earth heats up
0:12:31 > 0:12:36under the surface and all that means travelling down to the deepest,
0:12:36 > 0:12:37hottest corner of the mine.
0:12:40 > 0:12:42Millions of tonnes of rock above me,
0:12:42 > 0:12:47the boiling heat of the Earth not too far below, it sounds scary.
0:12:48 > 0:12:51I feel a little bit scared.
0:12:51 > 0:12:55The closer you get to the Earth's hot mantle, the hotter it gets.
0:12:55 > 0:12:59On average, the ground heats up by 25 degrees Celsius
0:12:59 > 0:13:02for every 1,000m you travel into the Earth.
0:13:02 > 0:13:05They call this the geothermal gradient.
0:13:05 > 0:13:07In a mine as deep as Boulby,
0:13:07 > 0:13:11that should mean a temperature in excess of 40 degrees Celsius.
0:13:11 > 0:13:15Sahara desert temperatures on England's chilly North Sea coast.
0:13:15 > 0:13:18And there's only one way in or out.
0:13:18 > 0:13:20The mineshaft.
0:13:21 > 0:13:25A token system checks that everyone who goes down into the mine,
0:13:25 > 0:13:27comes back up.
0:13:27 > 0:13:29It's a six minute journey down the lift shaft,
0:13:29 > 0:13:31which is 1,100 metres deep.
0:13:31 > 0:13:35Enough for three London Shards with room to spare.
0:13:35 > 0:13:37It's a bit like being on an aeroplane
0:13:37 > 0:13:39when you're going high, your ears pop.
0:13:39 > 0:13:42Well, it happens when you go deep underground, too. They've popped!
0:13:42 > 0:13:44Feels really weird.
0:13:47 > 0:13:48I think we're almost there.
0:13:56 > 0:13:58So I've made it to the bottom.
0:13:58 > 0:14:00I can't believe how windy it is down here.
0:14:00 > 0:14:04But that's because they're blowing air right through this mine.
0:14:04 > 0:14:06That's to keep everyone breathing, of course,
0:14:06 > 0:14:08and the machinery nice and cool.
0:14:08 > 0:14:11But, my journey has only just begun.
0:14:13 > 0:14:16It's another 10km out to the hottest part of the mine,
0:14:16 > 0:14:21and I have to go even deeper into this sweltering, underground city.
0:14:21 > 0:14:25Up to 300 miners are down here at any one time.
0:14:25 > 0:14:30And they all have a personal supply of iced water. My guide is Carl.
0:14:30 > 0:14:32He manages the potash mining
0:14:32 > 0:14:35and has over 30 years' experience underground.
0:14:35 > 0:14:38I want to know how he copes with the heat.
0:14:38 > 0:14:40I don't think you ever get used to it,
0:14:40 > 0:14:42but you have to certainly think about what you're doing
0:14:42 > 0:14:46in respect of taking water on board and keeping yourself hydrated.
0:14:46 > 0:14:49That's the key to it all, is hydration.
0:14:49 > 0:14:51HOOTING
0:14:51 > 0:14:54There are over 900km of tunnels in the mine.
0:14:54 > 0:14:58That's about the distance from Land's End to John O'Groats.
0:14:58 > 0:15:04As well as inland, they also stretch 7km out under the sea.
0:15:08 > 0:15:11- It's feeling a lot warmer now.- You've still got a fair way to go, yet.
0:15:11 > 0:15:14- Yeah.- I mean, this is actually still very, very cold.
0:15:14 > 0:15:19- It's going to get warmer?- It's going to get significantly warmer.
0:15:19 > 0:15:22Along the way, we pass towers of wooden blocks.
0:15:22 > 0:15:23They look like giant stacking games,
0:15:23 > 0:15:27but are actually helping hold up the roof of the tunnel.
0:15:27 > 0:15:30You can see how the wood is slowly being crushed by the vast weight
0:15:30 > 0:15:33of rock just above our heads.
0:15:33 > 0:15:38After half an hour driving, we finally arrive at our destination.
0:15:39 > 0:15:43The heat is overwhelming. The sweat is incredible.
0:15:43 > 0:15:44I don't know if you can see that.
0:15:44 > 0:15:47And now, I'm going to head for the face of the mine.
0:15:49 > 0:15:52The mine face is where the actual mining takes place.
0:15:52 > 0:15:56Giant machines cut through the Earth, collecting potash and salt,
0:15:56 > 0:15:5824 hours a day.
0:15:58 > 0:16:01What sort of machine could create tunnels like this
0:16:01 > 0:16:02through solid rock?
0:16:04 > 0:16:06This sort of machine!
0:16:08 > 0:16:12The Heli Miner, a 90 tonne state-of-the-art mining monster.
0:16:12 > 0:16:14Costing £1.5 million,
0:16:14 > 0:16:20it's the most powerful remote-controlled toy on the planet.
0:16:20 > 0:16:23They're just moving it forward now, and it needs constant air and water
0:16:23 > 0:16:26to cool it down because it's so hot here.
0:16:29 > 0:16:31The monster goes back to sleep.
0:16:31 > 0:16:34Time to check out the Heli Miner's handiwork.
0:16:35 > 0:16:39So this is the deepest, hottest part of the mine. This is the mine face.
0:16:39 > 0:16:42And you can see the grooves that that beast of a machine
0:16:42 > 0:16:46has been spinning against the hard rock. It's really hot here.
0:16:46 > 0:16:48And I've been all over the world for Fierce Earth,
0:16:48 > 0:16:51including the Sahara Desert, and it's way hotter here.
0:16:51 > 0:16:55It's really stuffy and dry. But let's check out just how hot it is.
0:16:55 > 0:17:00What I want to do is touch the rock here and see how hot it is.
0:17:00 > 0:17:02And that feels like touching a radiator.
0:17:02 > 0:17:05The heat is all coming from the rock itself.
0:17:05 > 0:17:08Let's just get an exact temperature.
0:17:11 > 0:17:12Just put it there.
0:17:14 > 0:17:18So that's flicking. Yeah. 42 degrees.
0:17:18 > 0:17:21Now that is incredible.
0:17:21 > 0:17:2542 degrees is around as hot as it ever gets in Thailand, Brazil,
0:17:25 > 0:17:27or the Caribbean.
0:17:27 > 0:17:31The average temperature above ground here is just ten degrees Celsius.
0:17:31 > 0:17:34Down in the mine, it's four times hotter,
0:17:34 > 0:17:36all thanks to the boiling Earth.
0:17:36 > 0:17:39Amazing though it has been down here, I'm ready to head back up
0:17:39 > 0:17:41and get out of this heat!
0:17:41 > 0:17:45But I couldn't leave without mining a little bit of rock salt.
0:17:45 > 0:17:47Now, it's a long way to come for a bit of salt,
0:17:47 > 0:17:50but I'm on a mission for Dougal in Iceland.
0:17:50 > 0:17:54Whatever could he want with this? All will be revealed!
0:17:59 > 0:18:02Sometimes the heat from the ground isn't just a hazard
0:18:02 > 0:18:05that miners have to put up with when mining rocks.
0:18:05 > 0:18:08Back in Iceland, it's the very heat itself that's being mined.
0:18:11 > 0:18:15So far, the boiling earth we've seen in Iceland has given us
0:18:15 > 0:18:17spectacular geysers.
0:18:17 > 0:18:19Pretty, but not very useful.
0:18:20 > 0:18:22I'll give you useful.
0:18:22 > 0:18:25Woo! SHE LAUGHS
0:18:25 > 0:18:28This vast blue lagoon contains hot spring water
0:18:28 > 0:18:30from deep within the Earth.
0:18:30 > 0:18:32There are over 170 of these hot spring
0:18:32 > 0:18:36pools across Iceland for the 300,000 people who live here.
0:18:36 > 0:18:40To bathe with friends and family is a big part of Icelandic life.
0:18:40 > 0:18:41The hot springs are fun,
0:18:41 > 0:18:45but they also show us that Icelanders take their boiling Earth seriously
0:18:45 > 0:18:49because it's the source of endless, more of less free, power.
0:18:50 > 0:18:54The hot water in the Blue Lagoon hasn't come directly from the Earth.
0:18:54 > 0:18:58It's passed through this huge power plant first.
0:18:58 > 0:19:00The water is actually the leftovers.
0:19:00 > 0:19:03This steaming heat is all that remains of the energy
0:19:03 > 0:19:05that has been extracted by the power station.
0:19:05 > 0:19:11When it comes to power, Iceland is the ultimate eco-friendly nation.
0:19:11 > 0:19:14In Iceland, the five geothermal power stations provide
0:19:14 > 0:19:19an incredible 25% of the energy needs for the country.
0:19:19 > 0:19:22In fact, they've got so much power,
0:19:22 > 0:19:26they even heat their pavements to stop the ice collecting in winter.
0:19:26 > 0:19:28And the source for all that power?
0:19:28 > 0:19:31Well, it's right beneath us, deep within the boiling Earth.
0:19:40 > 0:19:44This is a bore hole, forming a man-made geyser.
0:19:44 > 0:19:46It's pretty straightforward to make
0:19:46 > 0:19:48in a landscape as volcanic as Iceland.
0:19:48 > 0:19:52The hot volcanic rock is underground, just beneath our feet,
0:19:52 > 0:19:55and all you need to do to get to it is drill a bore
0:19:55 > 0:19:57hole down to around 2,000 metres,
0:19:57 > 0:19:59and up shoots endless boiling water and steam.
0:19:59 > 0:20:02The bore hole is really amazing.
0:20:02 > 0:20:06You can hear it bellowing steam out and you can smell the sulphur.
0:20:06 > 0:20:09But by itself, it's not really very practical.
0:20:09 > 0:20:13However, if I attach a pipe, like you can see over here,
0:20:13 > 0:20:16I can bring the steam all the way round to here.
0:20:16 > 0:20:21And if I drill loads more bore holes, and I attach lots more pipes,
0:20:21 > 0:20:23I can take the steam absolutely anywhere.
0:20:23 > 0:20:26Yeah, perhaps even down to that brand-new,
0:20:26 > 0:20:29state of the art geothermal power station,
0:20:29 > 0:20:31right down the hill there.
0:20:31 > 0:20:33- I was just about to get to that. - Come on.
0:20:35 > 0:20:39These pipes are full of water and steam as hot as 370 degrees
0:20:39 > 0:20:43centigrade, nearly four times hotter than a boiling kettle.
0:20:43 > 0:20:46They transport the heat from three volcanic systems in the hills
0:20:46 > 0:20:48all the way to Hellisheidi,
0:20:48 > 0:20:51the second largest geothermal power station in the world.
0:20:55 > 0:20:59The final destination for the steam is to power these giant turbines.
0:20:59 > 0:21:03The turbines look like jet engines, but work like windmills.
0:21:03 > 0:21:06The high pressure steam spins hundreds of blades inside,
0:21:06 > 0:21:08which generate electricity.
0:21:08 > 0:21:12This is geyser harvesting on a giant scale.
0:21:12 > 0:21:15There are five turbines behind me and the combined power is
0:21:15 > 0:21:18enough to produce electricity for 50,000 people.
0:21:18 > 0:21:22Now that is amazing, isn't it, Dougal?
0:21:22 > 0:21:23Dougal?
0:21:24 > 0:21:28As the energy around here is more or less free,
0:21:28 > 0:21:31I don't think they'll mind if I borrow a little of it.
0:21:31 > 0:21:33Here I've got a miniature turbine -
0:21:33 > 0:21:34it's a bit like a windmill -
0:21:34 > 0:21:40attached to a motor which is, in turn, attached to this little light.
0:21:40 > 0:21:42Now hopefully, if I can use some of this steam,
0:21:42 > 0:21:44I might get some electricity.
0:21:49 > 0:21:52Wow. There you go.
0:21:52 > 0:21:53Free electricity.
0:21:56 > 0:22:00And with the steam here being generated by the boiling
0:22:00 > 0:22:03Earth beneath us, this is energy that will never run out.
0:22:06 > 0:22:08Wow!
0:22:10 > 0:22:14The power stations of Iceland show how human beings never stop
0:22:14 > 0:22:17inventing, and it's the same story all over the planet
0:22:17 > 0:22:20wherever there is geothermal activity.
0:22:26 > 0:22:28We're heading to the far north of Iceland now,
0:22:28 > 0:22:31right on the edge of the Arctic Circle,
0:22:31 > 0:22:33but if anything the ground is hotting up.
0:22:35 > 0:22:39We're surrounded by some of the most amazing columns and turrets of rock.
0:22:39 > 0:22:42These were once all red hot lava.
0:22:42 > 0:22:47How could this have happened, up here in the north of Iceland?
0:22:47 > 0:22:49It's so cold and icy. What was going on?
0:22:49 > 0:22:52As ever, the clue is in the boiling Earth.
0:22:54 > 0:23:00This is Krafla, the closest you can get to the origins of the planet.
0:23:00 > 0:23:02It's terraforming in action.
0:23:02 > 0:23:06Iceland's splitting at the seams and growing year by year.
0:23:06 > 0:23:08- Wow!- That is amazing.
0:23:08 > 0:23:11This is where all that lava's coming from...
0:23:11 > 0:23:14giant cracks in the Earth's crust.
0:23:14 > 0:23:16This is the Atlantic ridge.
0:23:16 > 0:23:21It's incredible to think that this tear actually runs all
0:23:21 > 0:23:26the way from the top of Iceland right down to the very bottom.
0:23:26 > 0:23:27You have that piece.
0:23:27 > 0:23:29So I've got the American plate...
0:23:29 > 0:23:31And I've got the Eurasian plate...
0:23:31 > 0:23:33And there you have it.
0:23:33 > 0:23:36Iceland literally tearing itself apart.
0:23:37 > 0:23:39Have you ever wondered what planet Earth
0:23:39 > 0:23:42was like millions of years ago when it was just forming?
0:23:42 > 0:23:46Before people, before dinosaurs, before anything.
0:23:46 > 0:23:49The living landscape of Iceland is your answer.
0:23:51 > 0:23:54Fumerals are natural vents that constantly belch
0:23:54 > 0:23:56steam from under the ground.
0:23:56 > 0:24:00The steam brings up sulphur that dyes the rocks yellow.
0:24:00 > 0:24:02Whoa!
0:24:02 > 0:24:06That stinks of bad eggs! You don't want to be near that.
0:24:06 > 0:24:09Now all the ground around us here, even up on the hill,
0:24:09 > 0:24:10has melted the snow.
0:24:10 > 0:24:12It's as though it's alive.
0:24:12 > 0:24:13It's an awesome sight.
0:24:13 > 0:24:15And for the first Viking settlers,
0:24:15 > 0:24:20who arrived over 1,000 years ago, the hot land was a real gift.
0:24:20 > 0:24:22And I know some people can show us why.
0:24:25 > 0:24:28Iceland was first inhabited by Vikings,
0:24:28 > 0:24:32who travelled from Scandinavia over 1,100 years ago.
0:24:32 > 0:24:34They left a country where life was tough
0:24:34 > 0:24:37and arrived somewhere even more hostile.
0:24:37 > 0:24:39But the boiling Earth helped them survive,
0:24:39 > 0:24:42and some of their traditions are still around today.
0:24:44 > 0:24:46Daniel, Lurvic, Margaret
0:24:46 > 0:24:51and Ragnaheida are Icelanders who have grown up in and around Krafla,
0:24:51 > 0:24:55direct descendents of the Vikings who settled all those centuries ago.
0:24:55 > 0:24:58What are you guys up to?
0:24:58 > 0:25:00We're baking bread in the Earth...
0:25:00 > 0:25:02using just natural heat.
0:25:02 > 0:25:05So, basically, you're using the ground as an oven.
0:25:05 > 0:25:06- ALL:- Yeah.
0:25:06 > 0:25:10- How hot does it get in there? - It goes about 90 degrees.
0:25:10 > 0:25:12How long does the bread take to bake?
0:25:12 > 0:25:14- 24 hours.- Oh! Well, I'm starving!
0:25:14 > 0:25:17Well, that's OK. We put some in for you yesterday.
0:25:17 > 0:25:19- That's a relief.- Well, that's good news.
0:25:19 > 0:25:20I brought some eggs as well.
0:25:20 > 0:25:23- Maybe we can bake those?- Yeah. - OK, let's do it.
0:25:23 > 0:25:26This one's broken already, so I think that might have been Dougal.
0:25:26 > 0:25:30LAUGHTER
0:25:30 > 0:25:32Put the eggs in there then.
0:25:32 > 0:25:34How long do you think the eggs are going to take?
0:25:34 > 0:25:36They're going to take about ten minutes.
0:25:36 > 0:25:40- So what do we do?- Well, we'll wait. - We will wait.- We'll wait.
0:25:42 > 0:25:44'Instead of an egg timer, the girls give us
0:25:44 > 0:25:46'a rendition of an Icelandic song.'
0:25:46 > 0:25:50BOTH SING IN ICELANDIC
0:25:54 > 0:25:56'And then it's the moment of truth.'
0:25:56 > 0:26:00Are we ready to see if our egg and our bread are cooked?
0:26:00 > 0:26:02A big moment.
0:26:02 > 0:26:05- There's the eggs. You take hold of them.- Here's the eggs.
0:26:05 > 0:26:09- Is the bread cooked? - Put it down like a sand castle.
0:26:09 > 0:26:10- Wow!- Look at that!
0:26:10 > 0:26:13I get the honour to cut it - brilliant.
0:26:14 > 0:26:16- Wow!- That is perfect.
0:26:16 > 0:26:19Bread cooked from inside the Earth.
0:26:19 > 0:26:20'The bread looks good,
0:26:20 > 0:26:23'and Dougal's brought a little surprise along to season the eggs,
0:26:23 > 0:26:25'courtesy of Leah.'
0:26:25 > 0:26:30This is Fierce Earth rock salt from the deepest mine in the UK.
0:26:30 > 0:26:33'Let's just hope our eggs are done.'
0:26:33 > 0:26:36- Yeah.- It's boiled! - A little bit of salt...
0:26:36 > 0:26:39Right then, let me just taste it. I'm going to go for it.
0:26:41 > 0:26:43- Is that good?- Lovely.
0:26:43 > 0:26:47That is beautiful bread, and it's really nice and warm.
0:26:47 > 0:26:49This is fantastic.
0:26:49 > 0:26:53A volcanic picnic, courtesy of boiling Earth.
0:26:53 > 0:26:55What do they say in Icelandic?
0:26:55 > 0:26:56THEY SPEAK ICELANDIC
0:26:56 > 0:26:59- Or, in British, good health. - Good health.
0:27:00 > 0:27:05Our amazing planet is alive with wondrous volcanic sights.
0:27:05 > 0:27:07We've seen fumerals,
0:27:07 > 0:27:08geysers,
0:27:08 > 0:27:12and touched the giant tears in the very fabric of the Earth.
0:27:13 > 0:27:17The heat from below can make life tough for miners in the UK,
0:27:17 > 0:27:21but give the gift of unlimited energy in Iceland.
0:27:21 > 0:27:23With such an incredible resource under the ground,
0:27:23 > 0:27:27the country will be surviving and thriving for thousands of years,
0:27:27 > 0:27:30all thanks to the boiling Earth.
0:27:33 > 0:27:36Next time on Fierce Earth...
0:27:36 > 0:27:40things get wet as we discover the power of waves and tides.
0:27:40 > 0:27:43Clare and Leo get a surf lesson,
0:27:43 > 0:27:46and Leah witnesses one of the fastest tides in the world.
0:27:46 > 0:27:49It's starting to get a little bit scary, actually.