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How Earth Made Us -

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(generated from captions) incredible natural wonders. Our planet is full of Look at that! Whoo! It has immense power... in our history books. ..and yet, that's rarely mentioned I'm here to change that. the power of the planet I'm looking at four ways has shaped our history. The power of fire... Oh... technological breakthroughs. ..that fuelled great Wind... HE CHUCKLES the rise and fall of empires. ..that has influenced Water... has directed human progress. Our struggle to control it inside the Earth itself. But this week, I'm looking hot and extreme. It's an unknown world, HE CHUCKLES for our conquest of the planet, It's provided the raw materials but at a price. of human history. This is the great untold story Hidden unseen within the Earth, are at work. extraordinary geological forces Hi. Gracias. Forces that have shaped our history. and appreciate them, To really understand into the Earth itself. I've got to go deep in northern Mexico - This is the Naica mine to one of the most the starting point for a journey on or in the planet. spectacular and extreme places I'm really starting to feel it now. the deeper in I go. I'm getting hotter and hotter, of what lies ahead. This heat is just a taste they call "Base Camp". Finally, I arrive at what is just so extreme, so oppressive You know, where I'm heading people, all of these control systems that I'm going to need all of these just to get there. and all of this kit over here another planet. It's going to be like visiting reveals the power of the inner Earth Beyond here is a chamber that to influence human affairs. But to get there, some pretty esoteric equipment. they've had to develop Get this. It's like a chain mail of ice cubes. It's heavy, isn't it? will keep me cool. The special refrigerated suit What a palaver! Yes. This brings down my core temperature? Oh, feels very cold suddenly. That's very odd! that's potentially lethal. But it's not the heat alone This is what? This is the oxygen? Yes, it's fresh air. Yes. You'll need it. It's fresh air. with nearly 100% humidity. The heat is combined If I breathed that combination, inside my lungs. moisture would begin to condense I'd start to suffocate. After about ten minutes, I'm ready? I don't feel ready. You're ready. OK. Without this suit, I could die. It seems a lot of effort, geological wonders of the world. but inside there is one of the HE BREATHES HEAVILY WONDROUS MUSIC That is unbelievable. This is just mad! Absolutely gorgeous, isn't it? This is la Cueva de los Cristales - cave of crystals for my money, the most spectacular discovered anywhere in the world. HE CHUCKLES around the world You know, I've travelled amazing geology, to see some of the most this place just tops it all. but this place - Look at it. It really looks perfect. they're so translucent. You can see through them, And there's different types. that are like roses building up You can see these ones pillars - absolutely magnificent. and then these columns, these no-one knew this chamber existed. Until recently, broke through by chance. It was uncovered when miners these extraordinary crystals You know, a pretty ordinary mineral - gypsum - are made up almost entirely of that astounds you. but it's the sheer scale of them forces This strange world is shaped by on human civilisation. that have had a profound impact HE PANTS This heat's just too much. Oh, this heat... It's unbearable. that's what it's all about. But, oh, hey, the heat - That's the whole point. that these crystals are here. It's this cauldron that's the reason 5km below the cavern... It's so hot because only about that is super-heated molten rock. ..is an area of the Earth's crust minerals from the surrounding rock. This heats water, which dissolves this mineral-rich water Phenomenal pressure forces and filled this giant cavern. up through cracks in the rock Here, the conditions were perfect crystallise back out of the water. for the minerals to slowly for over half a million years, The cave lay undisturbed growing so the gypsum crystals just kept and the cave was drained. until the miners broke through far more than create these crystals. But the hot inner Earth has done hidden just beneath the surface This incredible hot world for powerful geological events is a driving force of peoples throughout history. that have shaped the fate in Israel's Negev Desert. This is the Timna Valley Today it's pretty well deserted. But over 6,000 years ago, this place witnessed scientific breakthroughs. one of the world's first great Up until this point, from stuff just lying around - humans had made all their tools stone, wood, bone, could get their hands on. anything, really, that they 6,000-7,000 years ago, But then, between imaginative leap. our ancestors made an extraordinary contained a secret. They realised that the rock here These green bands are called malachite. And it was these malachite seams that around 6,500 years ago leap of human ingenuity. were at the centre of that incredible inside the crystal cave, Like the gypsum these bands of malachite rose from deep inside the planet formed when hot fluids and leaked into these rocks. But unlike gypsum, when malachite is heated up... ..it does something special. It releases a metal. Copper. You know, in its day, the pinnacle of technology. this copper axe head would have been For a start, it's weighty. with this, it would leave a dent. If you hit something or someone For another thing, it's hard enough to take an edge. And if it gets blunt, you just sharpen it up. You can still see evidence of the ancient smelting pits at Timna. But the copperworkers left behind a more striking memorial to their work. A network of hundreds of tunnels, all carved by hand. This was the first large-scale mining anywhere on the planet. Those early copper miners would have squeezed through these narrow shafts on all fours, smashing their way through the rock and hauling their pails of copper-laced ore back to the surface. You know, the copper revolution changed our relationship with the planet in a really profound way. For the first time, we were transforming what the Earth offered us and in the process creating entirely new resources. And copper was just the start of things to come. About 5,000 years ago, tin was added to copper to form a new, more durable metal alloy - bronze. By 3,000 years ago, refinements to the smelting process meant iron could be smelted out of rock. Metal tools became the foundation for human civilisation. So it's clear we owe a huge debt to those first copper miners at Timna. But we also owe a debt to the deep Earth. The key to Timna's role in early history is its location. The Earth's crust is divided into huge pieces called plates. Where they meet are cracks known as fault lines. Timna is next to the Dead Sea fault, which separates Africa from Arabia. This fault also connects Timna to the deep, hot interior of the Earth. It's this hot interior that is ultimately the source of all the metals that have so radically changed our history. Fault lines allow them to rise to the surface... ..just as they did at the crystal cave in Mexico. But fault lines began affecting human history even before the discovery of metals. In fact, we've been strangely drawn to these boundary zones ever since the dawn of civilisation. And you can see why in the barren wilderness of the Lut Desert in Iran. The landscape is covered in hundreds of holes arranged in rows. These holes in the desert can help explain our ancient attraction to fault lines. But that involves me going down one - something the locals seem a little bemused by. Hi. So this is it? HE SPEAKS LOCAL LANGUAGE That's tiny! I don't think I'll really fit. How deep is it? ROCK THUDS God! Apparently it's 50 metres. That's over 150 feet. OK, I guess we do it, huh? So we go down? And if this deep, dark hole wasn't scary enough, the method for going down is unconventional at best. So we take this, like a pulley? And this goes over the top, I guess. So do I go on this? You can't buy those, I bet you! I've never gone on a rope with a tripod pulled by a tractor before. So... TRACTOR ENGINE REVS Well, I think we should just do this before I change my mind. OK. What could possibly go wrong now? Blooming heck. It really is deep. Oh, this isn't natural. I'm getting lowered down into the bowels of the Earth here. I wasn't sure if I was claustrophobic but now I realise I think I am. It's so far up! Look at that. Oh, dear. I don't want to do this too many times. HE EXHALES METAL TAPS For over 2,000 years, local people have been digging shafts like this - by hand. And I get the sense I'm about to find out why. HE SIGHS All right, here we go. Hey hey! Ooh! Oof! WATER SPLASHES I misjudged it. Look at this! This is the answer. The essential ingredient of every civilisation on Earth. Cold, fresh drinking water. This is what made this remote corner of the Lut Desert one of the few places in the region that could sustain towns and cities. And I'll tell you... ...after a trip like that, this is so nice to have. HE SIGHS Right. I'm off to explore a bit. I want to find where the water's coming from. This tunnel leading off the shaft is called a qanat. It's one of many in this region, hacked out of solid rock to capture ground water that's stored deep below the desert. I feel as if I'm in an underground rain shower. I've travelled about, I don't know, a couple of hundred metres now and it seems to be getting smaller and smaller. HE GROANS It's a bit narrow here. Well, this is it. This is the source of all this water. It's just pouring in from here. Underground water exists beneath most deserts. But it's usually so far down, there's no practical way of getting at it. The difference is, here there's a fault line. The fault is full of thick clay produced by the grinding of the surrounding rocks as they rub along the fault line. This forms a clay dam, which water can't penetrate. Water flowing down from the mountains pools against the dam, creating an underground reservoir through which a qanat is dug to channel the water. Gravity does the rest. So originally the water would've been banked up against this fault line, unable to penetrate through the clay-rich barrier. But what the locals did was to cut a qanat across the fault line, breaching the barrier and releasing the water. It was a simple but brilliant piece of engineering. OK. Qanats were an ingenious early example of a mains water supply. The shaft is simply a way to get access to the tunnel carrying the water, so it can be repaired. Today, the qanats still carry water from underneath the Lut Desert into the nearby city of Bam, as well as irrigating date orchards for which this area is famous. Oh! Oh, it's so good to see blue sky. Oh! Yeah, thank you. But this place isn't a one-off. In fact, if you look back at the ancient world, you see a strong link between fault lines, water and the growth of some of the first cities. More than 2,000 years ago, Petra in Jordan was the most important trade hub in the Middle East. It was built along a branch of the Dead Sea fault and was entirely dependent on natural springs, which rose along the fault and fed its irrigation system. Nearby is Jericho, said to be the oldest city in the world. It was first settled 10,000 years ago because deep ground water rose along fault lines to create fertile pastures in the desert. More unusual is the ancient Roman city of Hierapolis. It was built next to these terraces of white rock. Here, it wasn't just water that was important - minerals carried in the water were thought to have revitalising powers. So Hierapolis became an important healing centre in the Roman Empire. Whether it was minerals, metals or water, ancient civilisations were repeatedly drawn to the resources that fault lines brought up from the deep Earth. It's a connection which lead 11 of the 13 most important civilisations of the ancient world unknowingly to build their cities close to a plate boundary. As the earliest civilisations developed, so the relationship between fault lines and human history became more sophisticated. They even played a role in the establishment of the most advanced early civilisation of all. 4,000 years ago, in the Bronze Age, the island of Crete was home to the Minoans. Their showpiece was the palace of Knossos. You can see by the sheer scale and sophistication of Knossos that the Minoans weren't just another early civilisation. This, in a way, was the beginning of modern society. Certainly, this was a place that you and I would have felt reasonably at home. There was running water, a sewage system and large stores of food and wine. It all allowed the Minoans to create a new kind of society. For me, all this is a moment in history that is much under appreciated. What the Minoans represent is a great pivotal point when life switched from being dictated by the grim realities of survival into something that we could actually enjoy. What the Minoans invented was the day off. And the Minoans took their pioneering responsibilities in this area very seriously. Now, this may look like a car park, but, really, this is where the paraphernalia of the Minoan leisure society really took off because this is one of world's first sports stadiums. In its day, 500 spectators would cram in here to watch boxing, wrestling, and the Minoans' most peculiar sport, bull-leaping. The basic idea was that you wait for a massive bull to run at you, then at the crucial moment, you grab hold of the horns and flip yourself over the top. How do you practise that? No-one knows why the Minoans leapt over bulls, but this bizarre sport was a forerunner to bull-fighting. But the real legacy of the Minoans was how they made their wealth. This was the Bronze Age. To make bronze, you need two metals - copper and tin. The problem was finding them. For the Minoans, copper was relatively near at hand in Cyprus, thanks to the fault line beneath it. Tin was trickier. Inside the Earth's crust, only two parts per million are tin, so it's much rarer. The hunts for tin led to distant lands that were at the edge of the then-known world. One such place was so full of tin that it was called the Cassiterides - "the tin islands". Today... ..we know it as Britain. But the centres of Bronze-Age civilisation were in the Mediterranean, 3,000km away. Tin was also found in other far-flung locations like Spain, Central Europe and even Iran... ..which meant tin had to be traded, and for this, Crete was perfectly positioned. The Minoans exploited their position at the crossroads of many different trading routes... ..to become the world's first maritime superpower. It may not seem like it today, was at the centre of the known world, but in Bronze Age times, this island with the mineral-rich heartlands and North Africa all around. of Europe, the Middle East about owning the raw materials For the Minoans, it wasn't so much how to put them together. as knowing what to do with them, worked out how to exploit the geology They built an empire because they'd on their doorsteps. that their neighbours had By the time of the Minoans, fault lines had been a crucial factor many early civilisations. in the success of But the Earth extracted a price for these riches. It was a price paid in full by the Minoans. At the heart of the story was a small archipelago 100km north of Crete. Today that island chain is known as Santorini, famous for its pretty white houses and rugged coastline. But at the time of the Minoans this was a busy port, the key to their trading empire. If Crete was the heart of the Minoan culture, then this place was its backbone, a centre of industry that helped fuel what was at the time the most advanced civilisation on the planet. But Santorini held a deadly secret. Unknown to the Minoans, major plate boundaries. it sat above one of the Earth's the European plate. Santorini formed when the African started sliding below inside the deep Earth, As the African plate melted molten rock rose back to the surface to create what is actually a volcano. OMINOUS RUMBLING Around 3,500 years ago, what volcanoes tend to do - this volcano did it blew up. Unluckily for the Minoans, of the last 10,000 years. it was the biggest eruption why the eruption was so devastating Today you can still trace in the cliffs around Santorini. and rock spat out by the volcano. This cliff is made entirely of ash It's got distinct layers to it, different stages of the eruption. each of which are from is a timeline of events. In other words, this rock face helps understand the disaster Climbing this cliff anyone had ever seen before. that was unlike anything the start of the eruption. This level here was the Minoan land surface. I'm kind of standing on And in the next five hours, an enormous mushroom cloud of debris. the eruptions threw out after ash after ash. It just rained down ash glass. This stuff is just like a silica and it just lacerates your lungs. It gets into your lungs You just choke on it. This innocent-looking gravel stage of the eruption. was from the second and most lethal Sea water invaded the volcano with molten lava and that mix of water incredibly violent eruptions produced a series of superheated gas and debris that punched a jet of high into the atmosphere. fell back to Earth, As these clouds of hot gas and lava of the island. they engulfed the outer edges Ay! the worst was still to come. But, incredibly, everything that was in its guts, Once the volcano had spewed out into the void below, the weight of it collapsed producing the most enormous blast. of that final blast, And in the death throes catastrophic flourish. there was one last crashed into the sea. The centre of the volcano created a gigantic tsunami... That sudden collapse across the Aegean towards Crete. ..which quickly spread out WAVE CRASHES whose strength was in their navy, For a civilisation devastating. the tsunami would have been swept through the Aegean, It's thought that as the tsunami it engulfed the Minoan harbours, smashed into matchsticks. and any boats in them would have been that not a single boat So perhaps it's not that surprising from the vast Minoan fleet has ever been found. the Minoans would never recover. This was a catastrophe from which and a giant tsunami A long chalk-and-ash cloud was on its knees. meant that this maritime power their population decimated With the fleet gone, obliterated, and their most strategic trading post the Minoans went downhill fast. eruption, Within a century or so of the was finished. this once-great civilisation The eruption of Santorini was an extreme event. But ancient history is littered with along plate boundaries. tales of cities destroyed that do the damage. And it's not just volcanoes another deadly force of nature. Fault lines are also home to Earthquakes. earthquakes can be. reminder of just how devastating Recent events in Haiti are a of the deep earth example of how the destructive power The appalling disaster is a terrible can be concentrated along fault lines Over the past 10,000 years, to take advantage of fault lines many cities first established have been flattened. Hierapolis, with its famous health spa, in AD 60. was destroyed by a giant earthquake world, Jericho, the oldest city in the by large earthquakes. has been hit over 15 times Some believe it was this "tumbling down". that famously brought its walls Likewise, Petra was abandoned its irrigation system in AD 360. after an earthquake demolished And it continues to this day. famous for its qanats, In 2003, the city of Bam, a massive earthquake was devastated by which killed over 30,000 people. much of human history It makes you realise that, in effect, has centred on a bargain between us and the inner Earth. Plate boundaries provide access deep inside the planet. to resources from and then you take a hit. But live near one, and every now of our ancestors But even the most advanced this strange coincidence. had no way of explaining in the last 50 years In fact, it's only understood that scientists have finally struck all those years ago. the bargain that was inadvertently in the middle of the Pacific Ocean. You can see the theory in action Island. This is Kilauea on Hawaii's Big active volcanoes on the planet It's one of the most of magma deep inside the Earth because it's fed by a chamber called a hot spot. a hole in the Pacific plate - The hot spot has effectively punched on which Hawaii sits. the piece of the Earth's crust and something strange is revealed - But remove the ocean around Hawaii stretching along the sea bed a chain of mountains for over 5,000km. is explained This line of extinct volcanoes plate is continually on the move. when you realise that the Pacific this stationary hot spot, As the plate drifts over a volcano forms, but after about a million years, away from the hot spot. the moving plate pulls the volcano forming a new island. Meanwhile, another eruption begins, but it hasn't got long to go. Today, Kilauea is still growing, In a few thousand years, it will drift away from the hot spot and eventually disappear beneath the waves. The Hawaiian islands chain is a beautiful demonstration of a big idea that explains why plate boundaries bring us extraordinary benefits and terrible hazards in equal measure. It's called plate tectonics. The key is that all the plates, which divide the Earth's surface are continually on the move. Where they collide, they crumple the land to form great mountain ranges, like the Himalayas. Where they pull apart, oceans form in the gap. The friction of this continual movement means that plate boundaries become melting zones where minerals are concentrated and are able to rise towards the surface. But the flip side is that huge amounts of energy are concentrated along the plate boundaries. When one plate slides underneath another, volcanoes form. When two plates lock together and then suddenly break free, the jolt causes devastating earthquakes. So we now know that plate boundaries are so rich in resources for exactly the reasons they're so dangerous. Yet the strange thing is this groundbreaking discovery has made little difference to where we live. If you look at the plate boundaries, it's clear that many cities are located close by. In fact, 10 of the 20 largest cities in the world are next to dangerous fault lines. So why are we still building next to these danger zones? In the rugged hills of central California is part of the answer. And to see it, I'm heading into the skies. At least, I hope I am. This is the dinkiest helicopter I've ever been in. It'll be nice when it's finished. MOTOR STARTS I'm going to see perhaps the most famous geological feature on the planet. And this is the best way to find it. Yeah, yeah, yeah, this is it. This looks fantastic. It's this beautiful funnel cut right through these hills here. That's amazing. This line of hills with a trench cut through the middle is the San Andreas Fault. This fault is a boundary between the North American Plate to the east and the Pacific Plate to the west. For 25 million years, they've been grinding past each other to create the largest earthquake fault in North America. The San Andreas Fault starts up there in northern California, then slices down through 700 miles through here down to the border with Mexico. As it goes, it cuts through cities and towns and passes across a path of roads, bridges, aqueducts and fibreoptic cables. If ever there was a fault line that cut through the very fabric of a modern society, then it's this one. But a good reason why over 20 million people carry on living so close to this danger zone is that this plate boundary has made California rich. It began with the Californian gold rush. These nuggets of gold might have been found in streams, but the gold originally rose in hot mineral-rich fluids forced up between the plates. In fact, almost everything that makes California wealthy is at least partly related to the San Andreas Fault. Take, for example, the scenery. It was the colliding plates that forced up mountains along the Californian coast. And this dramatic landscape attracts thousands of tourists every year, who spend an estimated $2 billion on sightseeing alone. Then there's the wine. That's partly down to the San Andreas too. California is mostly desert but when moist air rolls in off the ocean and hits the mountains, it rises to form rain that irrigates this otherwise arid landscape. It's a microclimate that has made this one of the most productive farming regions in America. But the ultimate gift of the San Andreas is this. HISSING Oil. Black gold. This is an oil seep, which is when oil leaks to the surface, like a natural spring. HISSING Except this is black and gooey. Look at that. 150 years ago, when the first people were looking for oil, even the most witless prospector realised that places like this were a good place to drill. And drill they did. Over the years, around 200,000 wells have been sunk here. Most people probably think of Texas as America's oil state but California was and still is one of the world's biggest oil producers, drawing more than 700,000 barrels of crude oil out of the ground every day. The oil formed millions of years ago, deep inside the Earth. But it was the San Andreas Fault which split the rock and brought it close enough to the surface to be exploited. So it seems that the San Andreas Fault has brought California some serious economic benefits. Its shaping of the land has created the conditions for oil, for agriculture, for wine and even for tourism. But how much is that really worth? The money men have done the sums. They reckon this state earns around $100 billion every year because of the San Andreas Fault. California's geology is a licence to print money. Earthquake geologists like me know that California gets struck by a big seismic shake every 100 to 150 years. And those major quakes are hugely destructive. That doesn't seem to dampen the spirits of the number-crunchers that are in these skyscrapers. It's worked out that in a city like LA, a major earthquake will cause up to $250 billion worth of damage. Now, that is a huge sum. But averaged out over a century, you're still in profit. You've got $100 billion a year coming in, versus a one-off hit of $250 billion. That's a gain of 40 to 1. Any economist will tell you that's a pretty decent return. 10,000 years after our ancestors first settled along plate boundaries, the benefits of living along a fault line are as potent as ever. The point is that in pure economic terms, we're still financially better off living along a fault line than not, even when it's one of the most active in the world. But the problem that I have with that equation is that life's not just about money. Istanbul, the only city in the world to straddle Asia and Europe. This location at the crossroads of two continents has made it a trading hub for centuries. That's why I find it so exciting. It's a vibrant, bustling, cosmopolitan place. But Istanbul's location also brings with it great danger. Nearby lies the North Anatolian Fault, one of the most seismically active plate boundaries on the planet. Scientists reckon a major earthquake is due here any time. There's little doubt that in the very near future, Istanbul will be struck by a big earthquake. It's a strange feeling that this city that I love could be destroyed in my lifetime. But it doesn't have to be. Here, they're starting to rewrite the terms of our ancient bargain with fault lines. The aim is to enjoy the benefits of living along this plate boundary without having to pay a price in human life. Below the waters of the Bosphorus, the channel that separates Europe from Asia, is a clue to the solution. You know, this is such an eerie feeling. I'm 35m below the level of the Bosphorus and I'm walking parallel to one of the most active earthquake zones in the world. So not the kind of place you expect to find a major engineering project, and yet that's exactly where the Turkish authorities decided to build an underground train line. This tunnel, which will one day link Asia to Europe, is the deepest tunnel of its kind on Earth and yet it runs alongside one of the most dangerous earthquake faults in the world. These engineers are confident they've got the risks covered. Through some technical wizardry, the whole tunnel's designed to absorb the vibrations of even the largest of earthquakes. What these guys are doing, effectively, is confronting the earthquake threat head-on. This technology won't allow us to stop earthquakes, but it shows that if we really want to protect against their consequences, we can. Unfortunately, in Istanbul, this tunnel is only half the story. You know, high-tech underground train tunnels are all very well, but the reality is that most people who'll die in the next earthquake will die because the buildings that they live and work in collapse. And in that sense, Istanbul is completely unprepared. It's reckoned that when the next earthquake comes, it might bring down a quarter of the city. And the thing is, it doesn't have to be like that, because we have the technical know-how to keep buildings standing. The irony is Istanbul already has a building that has survived earthquakes for centuries. This magnificent building is the Hagia Sophia. It's got to be my favourite place in the city. For the tourists that come here, this is a fitting symbol of Istanbul's reputation as a crossroads of different civilisations. In its 1,500-year history, it's been a church and a mosque and now a museum. The Hagia Sophia has stood through more than a dozen earthquakes, without the benefit of modern technology. It was built on such a massive, monumental scale that even the biggest earthquakes never managed to knock it down. You know, it's no accident that when the earthquake does strike, the two things that'll probably survive are one of the oldest buildings in the city and one of the newest. And that's because they're both structures that we've decided are worthy of looking after. Today, we have the technology to protect every building - whether it's flats, factories or offices... ...if we choose to. For 10,000 years, we've lived with the benefits and the dangers of fault lines. You know, it's clear that people are going to continue to live along fault lines - probably for the next 10,000 years. But now we have two clear options - stick with the old regime and take our chances or embrace the new and take some kind of control. The trouble is protection doesn't come cheap. Reinforcing every building in an earthquake zone would be massively expensive. So even with all our knowledge, the deep earth is going to continue to confront us with tough choices for years to come. Next time, the magic of water. It's constantly transforming itself. Shifting between guises and from place to place. Our struggle to control it has shapped the desiny of some of the greatest civilisations in history Subtitles by Red Bee Media Ltd E-mail subtitling@bbc.co.uk