Birth of Britain 1of3 Hidden Volcanoes

you might think we live in a tranquil country where the land we live in is nice and stable and has always looked the same nothing could be further from the truth the beautiful country that surrounds us the rugged coastline the rolling green hills the craggy mountains were forged millions of years ago when Britain was a very different place giant geological forces have shaped the land we know today and the evidence is hidden in the landscape right beneath our noses it's an epic story of giant volcanoes colliding continents and of how Britain was ripped away from what is now North America is the story of the birth of Britain volcanic eruptions like these are some of the most terrifying and overpowering events on our planet and I'm not just talking about choking the skies with ash and stopping air travel I'm talking about colossal explosions incinerating gas clouds raining fire bombs and unstoppable rivers of molten rock these awesome forces of nature have shaped the world as we know it today but you might think nothing like this would ever happen here volcanoes would never rear their heads in Britain well you'd be wrong I'm going on a 1500 mile adventure to discover how volcanoes of shaped and built Britain and how they've played a crucial role in sculpting some of our most glorious landscapes and historic cities be prepared to be blown away by our volcanic past for my first evidence of volcanoes in Britain I'm heading to the ancient city of Edinburgh Edinburgh was home to one of the greatest scientific minds of all time in the 1780s James Hutton a gifted medic and chemist made an absolutely revolutionary discovery Edinburgh had once been a gigantic volcano before Hatton most people believe the rocks of Britain had been laid down in thin layers by a cataclysmic biblical flood 6000 years ago but Hutton was sure that had to be wrong he was obsessed with rocks and his detailed observations of how they formed would rewrite history and the way we see rocks forever i'm on my way to arthur's seat an 800 foot high hill overlooking edinburgh i'm gonna meet dr. kathryn good enough who wants to show me some evidence Hutton uncovered that led him to a surprising and controversial conclusion on one of the coldest most miserable days of the year we're going to look at an area of Arthur's Seat that sparked Hutton's imagination its extruder isn't that only a couple of hundred years ago everybody thought that the earth was just a few thousand years old but it was exactly I mean they thought that all the rocks everywhere on the earth had been laid down from ancient seas they talked about Noah's Flood and the fact that would have been a sea covering almost the whole of the earth and then you could lay down the ancient rocks from those seas and they thought every type of rock was laid laid down in that same way from those same agencies but hadn't found some rocks just around the corner here called basalt and he was sure they hadn't been formed beneath an ancient sea this was the section that he really looked at he sketched in his notebooks because what we can see here we've got these layers of sand and mud essentially and is what we call sedimentary rocks and if you follow these layers along and you can see it here they stop they cut off the bustle it's not only cut off is it it goes all the way around to the underside of the other road wrapped around the horizontal layers of sedimentary rock is a loop of solid bass 'old so what did he conclude from that he concluded these rocks these sands and modes must have been here first and that then this basalt must have been forced into these areas in that single moment of genius hadn't unlocked one of the greatest mysteries of the world he'd heard about lava erupting in Italy and he came up with a crazy idea could the same thing have happened in Scotland he proposed that the inside of the earth was so hot it turned rocks into liquid and then regurgitated them at the surface this was how the basalt had cut through the layers of sedimentary rock Hatton had correctly identified the tell-tale signs of an ancient volcano it's hard to imagine on a horrible rainy day like this but that means that once Arthur's Seat that towers over Edinburgh must have been an active volcano blasting heat out everywhere I wouldn't mind a very small active volcano here right now it was a truly astonishing revelation we're cobbled streets and tenement buildings now lie once a mass of molten lava flowed but sadly Hutton's revolutionary idea was largely ignored during his lifetime there was one really serious problem with Hutton's theories his style of writing was so bad no one had the faintest idea what he was talking about and it was only after he died that people began to realize how significant he was Hutton's great gift was being able to imagine dynamic geological events that shaped our land millions of years ago what I find so extraordinary about this whole story is that by looking very carefully at the rocks and by using his razor-sharp mind Hutton was able to paint a vivid picture of the distant past he knew that millions of years ago this whole area was under the sea but the popping out above the surface of the water were vast fire-breathing volcanoes Edinburgh is volcano was a monster a giant that rose thousands of feet out of an ancient sea lover spewed and exploded from its main cone and side vents and a thousand degrees Celsius Edinburgh is massive volcano has long been extinct and has eroded away all the remains is Arthur's Seat the tough basalt plug which once fed the main throat of the giant volcano but this volcanic beast didn't just leave its mark at Arthur's Seat remnants of it are scattered all over the city including and in burrows most distinctive landmark the city boasts one of the most impressive and impregnable castles in Britain but his success is due entirely to the local geology Edinburgh Castle wouldn't really be a castle without Castle Rock just like Arthur's Seat Castle Rock is a massive basalt plug all that remains of the side vent of Edinburgh is immense volcano it's a castle builders dream made from one of the hardest rocks in Britain Castle Rock is a massive ready-made pillar 250 feet high and 700 feet wide not even the most determined attack could undermine the foundations of this castle it's only when you get up close that you realize that the rock itself is an integral part of the castle that's on the outside but I'm about to get an exclusive view of the inside to see how the Foundation's were made most of the top of Castle Rock has been obscured from view as Castle after castle has been built above it historian Peter yeoman believes this rock literally is the bedrock of Scottish power he's agreed to take me down a secret passage to take a look into the bowels of Edinburgh Castle so this shaft was undiscovered for centuries that's right this this this existed here but it was filled up and it was only rediscovered at the beginning of the of the 20th century what's this massive wall behind you this is part of the the face of David Starr we'd have been standing in the open air 600 years ago and this is a great mass at the side of this Tara House though this is natural rock below that's right this gives you a very clear idea of what so much of the craggy summit at the top of the Castle Rock here would it look like so it's like a big historical secret isn't it you've got all the power and glamour and prestige of the massive castle up there and it's supported by this huge outcrop of natural rock and no one's really aware of it that's right this was the seat of royal government and if you held enra castle here towering over the city of edinburgh and the forth you held the heartland of the medieval kingdom so this vast lump of rock has played a pivotal part in Scotland's history so maybe it's not surprising that in many ways Edinburgh was the birthplace of geology but Hutton didn't just figure out how Edinburgh was made he was beginning to understand how the whole planet was created he realized that whether rocks were formed from molten lava or deposited by ancient seas it wouldn't take thousands of years to make them but probably millions in a flash of brilliance he realized the earth was very very old indeed Hutton was a really colorful character although you won't find any little blue plaques dedicated to him around here because legend has it that whenever he came to Edinburgh he stayed in his favorite brothel nevertheless some people say he was one of the top four or five scientists ever the Stephen Hawking of his time although it wasn't the age of the universe that Hammond was interested in but the age of our planet Earth Hutton's fascination with the age of the earth open the door for future generations of scientists to figure out our entire geological history I've spent a large part of my life digging for clues that are a few thousand years old but this story begins hundreds of millions of years ago when the Britain we know today was once scattered across the globe like pieces of an unmade jigsaw puzzle I'm going to explore how huge volcanoes have played a key role in bringing those far-flung pieces together the first step in the birth of Britain dotted across Britain hidden right beneath our noses and the remnants of a violent volcanic past geologists will tell you the volcanoes a key to understanding how the world works and I want to see how relevant that is to the creation of our small islands I've left the ancient and historic volcano in Edinburgh and I'm heading to Snowdonia Wales rolling back the clock millions of years to find evidence of some of Britain's oldest volcanoes the key to understanding the very birth of brimm Snowdonia is one of Britain's most breathtaking and serene landscapes and for me the only way to see it in its full glory is from the air but don't be fooled by its lush pastures and rolling hills this is a volcanic graveyard the site of one of the most ferocious battles Britain has ever seen a battle that would start to build the Britain we know today you know what this reminds me of you know if you visit a World War 1 site now and it's beautiful and calm and covered with grass and you can hardly believe that all the carnage took place there well that's what this is like it's stunningly beautiful it it's almost impossible to remember them at one time right here would have been virtual Armageddon from this central fent all the way to Mount Snowdon which is about 10 kilometers this whole area would have been covered in ash and volcanic rock wouldn't have been a great place back then but now we can see for yourselves kanya 450 million years ago at the same time that Snowdonia was ablaze with volcanoes the countries which now make up Britain lay on different sides of an ocean the lands that would become England and Wales were part of a strange southern continent and hundreds of kilometers to the north across an ancient ocean the lands that would become Scotland and Ireland also lay buried within the body of a massive continent hazal Pritchard a geologist from the University of Cardiff he's going to show me how Britain finally pulled itself together come on hazel she's taking me on a volcano hunting expedition and is going to recreate this epic battle scene as I suspected it involves a trek up a pretty big mountain been up here before yes several times there are some clues to what the environment was like here four hundred and fifty million years ago sure you know which way you're going yes not fine Apple to the untrained eye like mine this mountain is scattered with a random collection of rocks but to hazel their precise location on this huge mountainside reveals a fascinating story let's just hope she remembered to pop a compass in that handbag of hers this is what I really want to show you yeah it's just up here look around here you see it from there but is it this yes this thing here that's bizarre it looks like it's been squeezed out of a tube well he thought it was it's a fossilized pillow lava pillow lava this is a bit like what's happening in Hawaii today where you can see pillows forming under the sea around the coast so the plot thickens hundreds of millions of years ago I'd have been swimming in coastal waters with lava exploding under the water as it cooled it would have cracked and crackled like gunfire forming strange pillow shaped rocks hazel assures me that further uphill is rather more dramatic evidence of the immense volcanic battle that took place here so long ago this is something I really wanted to show you just here this rock yes looks like it's been rather badly pebble dashed isn't it well it's nature's pebble - those are the pebbles and you can see they're really stuck in the rock oh yes they are absolutely solid and they're volcanic bombs they've exploded from the center of volcano where we'd all have been coming from I've been coming from the vent which is up there oh yeah it is quite awesome isn't it because of that so hundreds of millions of years ago we'd have been standing on the side of an explosive volcano rising out of the ocean as it erupted it would have blasted thick sticky grenades of molten lava high into the air and as they fell they'd have rained down on the rocks below like shrapnel how big was this volcano hazel oh this was a mega volcano how do you know that huge volumes of ash we're standing on them here and there filling the whole hillside over there we're over there you see the striped rocks and then the whole of the hillside as you got was it stripy like that the stripes represent different eruptions these were pyroclastic flows pyroclastic flows are the deadliest weapons in a volcano's Arsenal if hazel and I had been standing here millions of years ago when this beast blew would have been engulfed by a lethal avalanche of burning gas and boulders racing towards us and over a hundred miles an hour this really is quite an extraordinary place because I know it's pretty difficult to imagine on a lovely spring day in the 21st century but 450 million years ago this whole area would have been awash with a tropical sea teeming with life and sticking out of the water there would have been these vast mega volcanoes spewing lava bombs and ash high into the air it would have been fairly spectacular but why were they all here the sheer size of these ash flows covering huge areas in Snowdonia revealed the true force of this volcano it was over a hundred times more powerful than Krakatoa imagine that ricocheting across the Welsh countryside and there wasn't just the one terrifying volcano here there was a whole chain of them aligned along the northern coast of an ancient continent the massive continent which contained the lands that would become England and Wales this ancient continent was pushing northwards as it did so it gobbled up the ocean floor which then remelted and was regurgitated as massive volcanoes along the coast and that's only half the story hundreds of miles to the north exactly the same thing was happening on an ancient continent containing Scotland in Ireland and this continent was heading southwards the landmasses were on a collision course gobbling up the ocean in between until finally England and Wales crashed into Scotland and Ireland the volcanic battlezone left behind isn't just found here in Snowdonia it extended north creating some of our most beautiful and iconic landscapes the Lake District 500 square miles of Ash and lava in places over three miles deep and 400 miles further north in Scotland Glencoe once a colossal super volcano which spectacularly erupted blasting out thousands of cubic miles of magma like an enormous wound this gigantic volcanic strip binds together the two halves of our nation finally all the bits of Britain came together the land that would become Wales in England crashed with what's now Island and Scotland who's a pretty slow three inches a year kind of crash but nevertheless it was a very important one because if it hadn't been for the movement of those tectonic plates the present-day journey from Land's End to John O'Groats would be a really long one but there's a problem with geology nothing stand still for long no sooner had the pieces of Britain been fitted together then it began to pull apart and once again gigantic volcanic forces were at the heart of the action so far in my quests to explore ancient volcanoes in Britain I've discovered the separate parts of England Scotland Ireland and Wales were brought together in volcanic mayhem when two massive continents collided forming a huge supercontinent the Britain was stuck right in the middle of it and so was the North American continent the next stage of my investigation is to understand how Britain wrenched itself free to shape the islands we know today and I'm keen to understand what role volcanoes played in its dramatic past to find out I'm heading north to one of our most iconic landmarks we're about to witness a titanic struggle as the rocks of Britain try to break free from the rocks that make up North America and the evidence of this battle suitably enough can be found right here underneath Hadrian's Wall I bet almost every schoolchild will tell you that the Roman Emperor Hadrian built a vast wall across northern England to keep the Scots at bay well that's really less than half the story Hadrian's Wall extends west from Wallsend on the River Tyne to the shores of the Solway Firth a distance of 80 Roman miles that's 73.5 modern miles in total but what amazes me is that although this was the biggest defensive structure in Roman times it took only six years to complete and that's because there's something rather special about the walls construction and location I've been up here to Hadrian's Wall lots of times because of the Roman history in the archaeology but to understand why it's here you need to see what it was built on and that means looking at the geology the Romans were canny engineers they deliberately made the wall follow the path of a vast half-buried slab of volcanic rock called the wind sill Hadrian's Wall is way up above me over there is Scotland so when the Scots are the pits as they were known then were attacking here the first thing they would have seen wouldn't have been Hadrian's Wall it would have been this to get an idea of the size of wind SIL once again I'm going to hitch a ride in a chopper and see it from the air it's only when you get up here that you realize quite how expensive the SIL is not only that you can see the shape of it - it really does look like a seal isn't it a windowsill really chunky sticking out in the landscape it's a massive geological feature this is just the leading edge of it but he goes back in that direction under the Northumbrian countryside for mile after mile this vast 20 meter high cliff stretches right across the neck of Britain and even extends beneath the North Sea so how was this gigantic slab of volcanic rock created and what part did it play in the birth of Britain Nick pet food from the University of Northampton has come to reveal all sick what's this great cliff face made of well to answer the question is good to get a fresh piece of material so I can look at it in a bit more detail some of the hand lens if I look closely in fact even with the naked eye I can clearly make out tiny crystals if you have a look you can perhaps see some of those white flecks yeah yeah so they're crystals and that tells me that the rock has cooled down relatively slowly that means that the crystals have had time to grow slightly larger so that tells me that this particular magma didn't reach the surface it intruded at some level beneath the earth a few hundred meters perhaps as the magma comes in it's if you like shielded or liked but the rocks are bobbitt therefore it takes a bit longer to cool down it's a bit like kind of lagging around your boiler you know this is this magma has been lagged but the rocks above it call it a bit more slowly and it's slightly coarser grain than you'd get if it erupted straight to the surface so this entire cliff was once a red-hot lair insulated and trapped by hundreds of feet of rock above it why did the magma come up in this great slab rather than shooting up through the surface as a volcano or a series of volcanoes what happens that 400 million years ago is that these two colliding land masses came together and formed a line which runs up from Wales up through the Lake District and up through the southern part of Scotland kind of wide boundary like this after this collision had happened something strange began that is that the crust to the south of this line this suture line started to stretch apart pull apart in this area and analogy would be sort of stretching pizza dough as you so stretchy Li gets thinner and that's the stretching continued magma from very deep down in the earth starts to move towards the surface but it doesn't break the surface and make a volcanic eruption instead its shoulders apart the horizontal layers of rock this spreads out laterally or sideways to abuser finally as it crystallizes a vast slab of rock 300 million years ago the land beneath me was stretching and thinning a gigantic tongue of molten rock almost 17 trillion cubic feet in size surged upwards but it never quite broke the surface no volcano exploded here instead the magma barged its way between the Buried rock layers exploiting this line of weakness it traveled right across the neck of Britain laying down a giant 150 foot thick 50 mile wide and 75 mile long slab of hardened magma beneath the earth and luckily for the Romans the layers of weak rock above it eroded down exposing the 70 foot vertical cliff of wind sill I always thought it was Hadrian's Wall that stopped the pics invading from the north but as you can see on its own it's really quite puny what was just as important was clearly that great lump of magma and it's not just here it's over there over there over there it stretches away as far as the eye can see but the stretching that created this enormous volcanic slab stopped after just a few million years and Britain remained attached to what's now North America eventually though a split did occur and Britain broke away to become the small islands we know today but the events of this final battle didn't play out here they happened on the dramatic western coast of Scotland 240 million years later and that's what I'm going to explore on the next leg of my journey looking at some of Britain's youngest and most humongous volcanoes who last after what's been a very long journey I finally come to the last chapter of our story 60 million years ago Scotland and the rest of Britain were firmly joined to what's now the North American continent but today America is 2,000 miles in that direction to find out how that happened I've come to the scene of the crime here to the exquisitely beautiful if slightly damp island of sky well it's a bright and early start and I've met up with volcanologist Dougal Jerram on the Isle of Skye so you're all made of this igneous rock he's going to help me understand how Britain moved 2,000 miles away from the American continent sky is a volcano fanatics dream on its eastern coast lies the remains of one of the largest and most spectacular volcanoes in Britain the black coolants these dramatic Peaks formed 60 million years ago at the same time that Britain made its break from North America well after an hour's ride across locks go vague we're finally nearing our destination well now we've sort of fishel II landed in the center of a volcano let's go and have a look at some of the marvels that we can see in the rock layers inside I'm keen to know just exactly how big this volcano was I must admit what I was expecting to see a massive cone-shaped volcano towering above the slight Mount Fuji in Japan Dougal assures me it'll all become clear so where would the top of the volcano appear well millions and millions of years ago if you can imagine where we stood today we're right in the sort of bowels of this system probably one to two maybe even three kilometres above us there was a volcanic vent sort of pumping out lavas and explosions to the surface so when you say where and the inside is that the magma chamber whether the lava was cooking up to eventually be spewed out yeah it's almost like the cauldron of the magma where the magma comes into the shallow surface of the earth blisters up before it erupts at the surface that's what we call the magma chamber or the magma chamber plumbing system sixty million years ago we'd have been standing inside the magma chamber at the heart of this colossal volcano its scale is almost unimaginable twelve miles across from this central reservoir magma rose to the surface creating a gargantuan volcano over two miles high and 15 miles long over millions of years this immense volcano has been eroded away and all that's left is its carcass the black coolants the exposed shell of its vast magma chamber how hot would it have been right here when the volcano was at its height when we see the same composition rock types erupting at volcanoes in Hawaii in Iceland these can be 1,100 1,200 degrees centigrade so four or five times hotter than the hottest temperature you can get in your your oven cooker at home so bit warmer than today then on a freezing day like this you can hardly imagine an immense volcano erupting here this volcano was erupting at the time when Britain was wrenched away from what's now North America but what extraordinary force created that volcano and caused a whole continent to be ripped apart my exploration of the volcanoes of Britain has finally brought me to the island of Skye home to one of our biggest ancient volcanoes and it was erupting at the same time that Britain made its breakaway from America what's even more puzzling is that this fiery beast wasn't just big it was one of the most prolific volcanoes on the planet I've seen the guts of this massive volcano Dugan's now hiking me 15 miles down the road to take a look at the outer edge of this monster and its unimaginably vast lava fields picked up of it yeah well the reason for dragging you this far Tony is to come to see this fantastic Bay in the island known as Talisker Bay here shears talisker Bay and all of these cliffs you can see all around us all the rocks up here the crags in talisca Bay all of these rocks behind along even those big cliffs up in the background this is all lava all of these motors all of these mountains yeah they're sheet upon sheet of basaltic lava flow what even that great lump of a mountain up there yeah I mean that's pressure more that's actually been fingerprinted almost like a DNA print back to the big volcano that we were we were in this morning it's a huge amount of love yet kilometers away from here traveling to this distance horn of lights were being around here when that was kicking off all this lava from just one single volcano the island is like one massive lava field mile after mile after mile the volcanic rocks hundreds sometimes thousands of feet deep the black coulomb's volcano spewed out thousands of cubic miles of lava it was like an unstoppable tap of molten rock it may have been one of the biggest volcanoes but it wasn't alone there were dozens more lava producing vents here 60 million years ago so why did skies volcanoes produce so much larva and what's this telling us about how Britain was ripped away from North America Duggal tells me a clue lies in the lava itself and his art here we go here's a lovely example just here that's extruded it looks like a great wet cow Pat oh yeah in some ways it does what you've got here is sort of a series of ripples that they're almost like ropes that form these textures called a rope a lava or pahoehoe lava flow how old is it well this particular flow is around about 58 60 million years ago so actually looking at the fossilized top surface of the lava and it's only really sort of visible here because of the way the waves have actually eroded this top surface it's almost revealed from removing tons and tons of lava above here this snapshot in time were able to see this this could probably erode away in a few hundred years time millions of years ago we would have been standing in a river of runny lava as it cooled the outer crust hardened but the inner molten rock continued to lurch forward creating rope-like lobes and building up in layer after layer over thousands of years what does it tell us about the birth of Britain well I think if you put the pieces together it's quite special we've got this this ropey / holy holy lava that only occurs when we have hot runny lavas we find these in high slen today and when we get hot upwellings of this really sort of low viscosity runny lava that happens when continents start to split apart so here we're actually seeing a snapshot of in effect The Smoking Gun of a process that's happening around about 60 million years ago the very point where we started rifting and drifting away from the american continent 60 million years ago Britain lay trapped between the American and European continents but then this massive continent began to split apart again when a huge current of molten rock surged upwards from deep inside the earth it hemorrhaged millions of tonnes of runny lava at the surface creating the volcanic mountains of sky all along the rift this rising molten rock also spreads sideways creating new seafloor and forcing the giant plates of the earth apart it pushed the American plate to the west and the European plate and Britain to the east and the North Atlantic formed in between creating the distinctive coastline of the British Isles over sixty million years this process has pushed Britain two thousand miles away from America the enormous heat deep inside our planet continues to power this process and as a result we're still moving away from America at the rate of roundabout three inches a year which is about the time it takes to grow your fingernails and for exactly the same reason there are still highly active volcanoes erupting today not here for hundreds and hundreds of miles away over there in Iceland Iceland now sits above the very same crack in the earth where sky once at these eruptions which today create new mountains in Iceland are the direct descendants of the volcanoes that once built sky and drove the continents apart when the earth splits open here it does so along terrifying mile-long tears in the ground would use millions of tons of lava in a matter of minutes this awesome spectacle is how the Isle of Skye must have looked 60 million years ago before its volcanoes were extinguished forever this volcanic process was so massive it not only created sky but also the magical islands of the Hebrides and some of the most precious volcanic wonders in the world including northern islands legendary Giant's Causeway ancient volcanoes have built our land and even today continue to shape our lives since James Harden first discovered a volcano in Edinburgh hundreds of remnants of our volcanic past have been found scattered across our landscape and imbedded in our history they tell an amazing story of how the jigsaw pieces of Britain collided together and how they pulled themselves apart again to become the islands we know today the history of the birth of Britain is an incredible story James heartened the father of geology figured out not only that Britain was very old but also that once it had been dotted with volcanoes in the distant past and we now know that those volcanoes were part of the process that smashed continents together and pulled them apart to create the Britain we know today for me it's been an incredible journey I've come to realize that the earth we live on is almost alive it's a dynamic planet one that never rests you

Channel: Reijer Zaaijer

Views: 484,989

Rating: 4.8088512 out of 5

Keywords: time, team, full, episodes, season

Id: aBWJZBdWug0

Length: 44min 58sec (2698 seconds)

Published: Mon Dec 02 2013