The Great Earthquake of 1755 – Lisbon's Nightmare | Documentary

the city of Lisbon November the 1st 1755. All Saints Day one of the most important days in the Christian calendar [Music] the date of one of the greatest disasters of modern times sixty thousand people will die in a single day [Music] scientists are still trying to pinpoint the source of that quake today the ocean threatens Europe with another huge disaster [Music] an earthquake followed by a tsunami the ultimate combination striking with a speed and power that astonishes even the experts [Music] in Lisbon in 1755 one man took control and rebuilt the city how would we cope today [Music] [Music] Lisbon the capital of Portugal on the western edge of Europe the greatest Harbor on the Atlantic seaboard today the Pearl on the river taga seems a completely normal City yet she hides a terrible Secret it's hard to find any buildings here more than 250 years old rare survivors of a colossal disaster [Music] Friday 31st of October 1755 the night before All Saints Day Halloween Gypsies and showmen have taken over the city Portugal may be a deeply Catholic country but there'll be plenty of time for church going and piety tomorrow a day that will throw all Europe into turmoil [Music] off the south coast of Portugal a team of marine scientists are searching for traces of a disaster in the past to help prevent one in the future a hundred kilometers out in the Atlantic they're probing and measuring the ocean floor three continental plates converge here seismically this is a highly active area I think the best is to move here Valenti sarayas and Mark Andre gutcher are plotting their route along the Azores Gibraltar fault Zone [Music] this sector has seen not just seaques but also tsunamis giant waves that have claimed thousands of victims and Europe is especially vulnerable the Mediterranean area the problem is that the time of hitting of a tsunami from the source to the course is very short much shorter than in the Pacific or in many places in the world so the classical alarm systems doesn't work very well so one of the main objectives of this project is to find a an alarm system which is adequate for so short timing more than 300 tsunamis have hit Europe and North Africa since records began four centuries ago at Messina in Sicily waves 30 meters high killed 80 000 people in 1908. there was no warning [Music] in Lisbon on the 1st of November 1755 a clear and sunny autumn day everything is running like clockwork King attends early Mass Joseph the first has been on the throne for five years he's a mediocre King but he has talented advisors above all his Chancellor Marques pombo a product of the Enlightenment his rival the Jesuit priest malagrida an enemy of progress the less the people know the more power flows to the church I know with the mass over the king departs for his country estate at Balaam outside the city [Music] by the time he arrives his guests will all be here Royal picnic [Music] it's a gathering of Lisbon's fabulously wealthy Nobles who've been exploiting the gold mines and slaves of Brazil for Generations but Portugal's economy has been stagnating for decades no one knows that better than Marquis pombal he's not popular at court he stayed away from today's celebrations to hold meetings in the city his great fear is that Portugal will become the most backward Backwater of all Europe Portugal manufactures almost nothing a quarter of all trade is in the hands of the British with German merchants in second place Carl Peterson is one of them he's a Protestant so he'll work on this Catholic holiday but he'll have to wait for his latest cargo to be released by customs on All Saints Day things take longer feast days and celebrations in Portugal are more important than work [Music] down on the key side next to the Royal Palace the brand new opera house is the pride of the city the King has had it built for 200 000 English pounds 50 million dollars today this is engineering state of the art the cogs and levers may still need human muscles to work them but they can recreate any natural or Supernatural phenomenon actors flying through the sky rainstorms volcanoes with unprecedented realism it sets new standards for the whole of Europe the stage is big enough to accommodate a coach and six trotting horses but already critics are rambling that the king cares for nothing but theater and religion [Music] in the city the churches are full to overflowing the people of Lisbon are famous for their piety and their superstition yourself the Inquisition has ruled here for 200 years later today there'll be a special attraction with Heretics burned at the stake the perfect ending to All Saints Day the Inquisition showing how God punishes unbelievers [Music] the Sumptuous Interiors of God's houses reflect the power of the church too no wonder they say if you haven't seen Lisbon you haven't seen Beauty the great city is famous for two things the veneration of saints sometimes verging on idolatry and it's legendary wealth [Music] a thousand ships a year tie up in Lisbon's Harbor loaded with spices and precious goods from the old and new worlds [Music] when gold was discovered in Brazil the king of Portugal became the richest Monarch in Europe but the ships that bring 15 Tons of gold to Lisbon every year across a dangerous stretch of ocean [Music] the one the scientists on the Hesperides are patrolling today they have five kilometers of sea beneath them but with the latest technology they can see into the very depths to scan the fault zones on the ocean floor a swath mapping system uses very high frequency waves of 15 kilohertz which are emitted from The Vessel they go through the water they hit the sea floor and they immediately bounce off the sea floor and are reflected back to the ship and this allows us to construct maps of the sea floor which we call bathymetry with lower frequency waves the scientists can actually penetrate the sea floor so they can see what's going on beyond the bottom of the sea [Music] they can spot potentially dangerous cracks and faults up to a few hundred meters beneath the seabed the trouble is most serious earthquakes start deeper up to 50 kilometers down and for that the team needs special sounding devices [Music] each of these ocean bottom seismometers cost twenty five thousand dollars they can measure seismic activity deep inside the earth an OBS on the inside has very sensitive sensors which can measure vibrations either in the water or coming from the ground beneath and these vibrations can be produced either from distant earthquakes or from a seismic vessel which is passing by and producing a an acoustic source that is to say air gun shots they need 30 ocean bottom seismometers for a 300 kilometer route the Azores Gibraltar fault Zone this area has repeatedly caused small earthquakes in the past each OBS is lowered up to five kilometers to the ocean floor it's no movement but the downward drift of marine detritus it takes thousands of years to add a centimeter to the seabed but exceptional events leave exceptional traces [Music] at the Marine technology unit of the University of Barcelona they store drill cores from the sea floor that contain remarkable information and her team work closely with the researchers on the Hesperides the samples in their course don't just provide a record of undersea earthquakes they can even reveal how often they happen because Quakes trigger Avalanches of sand and silt that settle in layers known as turbidites turbidites are Sandy to silty deep sea sediments they are deposited very rapidly from minutes to few hours these are the hemipelagic mats they are very fine-grained size sediments and they are deposited very slowly for example this part it would may take thousands of years to be deposited in contrast we can see here these abrupt base erosional base these are the sounds of the turbidite which it reached up to this height and it must be maybe it has been deposited in few hours the silt and sediment is organic material so it's an ideal candidate for carbon dating turbidite layers examined here suggest that a huge earthquake has occurred in this region roughly every two thousand years that may sound reassuring but the evidence isn't always as clear as the scientists would like because a big earthquake can leave a small footprint that was the case for the 1755 earthquake so even in the 1755 Lisbon earthquake had a very large magnitude the resulting thermostat is very thin so there is not our direct relationship between the thickness of the turbidite and the magnitude of the triggering earthquake there are other factors that may be taking into account for example the availability of sediments all the stability of the area citizens who went to early Mass are already filling the streets for the great All Saints Day Market the city's third of a million population is swollen by thousands of villagers who've walked in from the countryside ready to spend what little money they've saved on the biggest treat of the year but Carl Peterson has returned home like most Merchants he lives in the crowded baisha District above and behind the port it's not especially fashionable but it's ideal for his work within walking distance of the warehouses and the harbor but on a high Catholic holiday a Protestant like Peterson is best not seen in the streets [Music] and today he can look after his wife she's had a fever for nearly a week [Music] foreign there'll be no doctors on All Saints Day meanwhile out in the market the animals are panicking no one knows why [Music] and in Berlin the harmony of the picnic is suddenly Disturbed [Music] the king will Retreat to his country Palace a decision he will later regret [Music] in the city the houses start to shake people described a trembling as if a heavy coach were driving by outside they do nothing and lose valuable time but no one can know what these signs mean there hasn't been a serious earthquake for 150 years somewhere to the South West two continental plates suddenly shift with explosive power within two minutes the shock waves reached the capital at 9 40 am every church bell in the city begins to ring on its own then the sky falls in Kyle Peterson wrote to a friend suddenly I felt my house all five stories of it shaking Stones beams and root tiles fell about me if it doesn't collapse Marquez pombal has a narrow Escape too the streets are no safer as walls collapse into the narrow Alleyways the Tremors continue for 10 minutes three huge Quakes with Eerie periods of Peace in between everywhere the reaction is the same out of the houses away from the walls and rules into the open the earthquake will destroy three-quarters of the city's buildings seventeen thousand houses the opera house next to the keysight collapses like a house of cards but most victims are in the churches the house of God becomes a place of death tremors are felt on two continents recorded over 10 million square kilometers throughout Europe and North Africa foreign 's geological Institute they've made a special study of the earthquake Pedro terrina 2 works with the scientists on the Hesperides looking for the connections between faults in the Earth's crust and potential seaques Faults Are fractures and it is the movement of the blocks on on the fault that release elastic energy that generates the shake of the Earth or an earthquake to create an earthquake like that we have to release a huge amount of energy so a small fold cannot produce a big earthquake 1755 earthquake was big Lisbon's National Institute of engineering has one of Europe's biggest shaking tables this is where they test materials for tremor-proof buildings there's an earthquake somewhere in the world every day but on average only four a year actually destroy buildings [Music] today's test will mimic the enormous power of the Lisbon earthquake of 1755. the Tremors increases the computers follow the sequence of waves in a real earthquake the horizontal waves are the first to arrive they're known as primary or p waves the secondary waves travel at half the speed and their action is vertical this 30 square meter table can create the precise combination of horizontal and vertical vibrations it gives an earthquake its destructive power most building materials are brought down by a force 6 quake the Lisbon earthquake was a thousand times as powerful [Music] the exit magnitude of the Lisbon earthquake we don't know um but we it has been estimated as a magnitude 8.5 8.7 this was inferred from the intensity of the earthquake and damage on the different localities in the ivarian peninsula Kyle Peterson guides his family through the narrow streets towards the harbor [Music] it's back uphill to Rossi's Square with their lives [Music] in vain soldiers attempt to restore order [Music] but thousands forced their way past towards the harbor and the Royal Palace there's plenty of open space down there they can wait out the end of the earthquake but at the harbor a strange spectacle awaits them as if the tide has gone out and will never come back as though the water is fleeing the disaster to make room for the desperate citizens today at the Technical University in Berlin they can model any sequence of waves that takes their fancy by pressing a button they can create giant waves White Walls or the most deadly waves of all tsunamis a tsunami is different from other giant waves because it always gives a warning first the water pulls back it's almost an invitation to go into the water then the first tsunami wave comes it isn't always the highest then the water pulls back again and returns with the hugely destructive waves that in the tsunami disasters we've witnessed to claim the most victims a normal wave created by Tides sea currents or strong winds generally has a wavelength of 100 to 200 meters it'll break gently on the shore causing little damage [Music] tsunamis have a wavelength of a hundred to five hundred kilometers that means they carry a colossal amount of water in the open ocean they're barely noticeable but as they near the coast their height increases dramatically [Music] tsunamis are caused by seaques when continental plates collide with each other over a broad area but say 280 kilometers in length and breadth the entire body of water is raised by about half a meter to a meter this wave races towards the coast at a speed of up to 800 kilometers an hour as it reaches shallow water near the coast the wave gets higher 10 20 30 meters depending on the shape of the coastline and it does terrible damage when it arrives [Music] on the horizon a tsunami looks harmless as these pictures from Indonesia of the December 2004 disaster show [Music] in 1755 several ships encountered the tsunami swell at sea Sailors set their vessels shook as if they'd gone aground there was a rumbling sound like an approaching storm [Music] for those at the harbor that tsunami suddenly rears up caught between the city in Ruins and the Raging Sea 900 people perish instantly as the keysight is washed away by the waves 5am on the Hesperides this is a 24-hour job they're getting the air gun ready [Music] this monster weighs many tons it's connected to a compressor that provides the shock waves that will penetrate more than 30 kilometers into the seabed foreign [Music] will fire its ultra low frequency pulses every 90 seconds as the Hesperides sails above the line of the seismometers [Music] and this signal propagates into the into the water and the Earth's crust and then it's recorded by the obs the scientists are looking for distortions and fractures on the seabed that were the result of earthquakes in the past or could cause them in the future they know what kind of a fault might have caused the 1755 earthquake one with a big surface area and a huge vertical slip three successive tsunami waves kill thousands on the coasts of Europe and North Africa they even strike distant Scandinavia and the surges felt across the Atlantic in the New World but the Portuguese capital is hit hardest of all artists soon imagined the full horror of the disaster people barely feature powerless before the onslaught earthquakes giant waves a finally a blazing Inferno fall upon the city as if all the elements are conspiring against it the fires start in the kitchens soon they're flaying the homes and warehouses in the crowded bike shower anything the Quake left standing is now exposed to the flames Priceless stores of goods and years of business records are destroyed in minutes [Music] there's no point trying to put out the fires as the squalling winds repeatedly fan The Inferno within minutes whole districts are Ablaze and aftershocks continue to shake the city in the hospital 400 patients burned to death by the afternoon the whole city is burning [Music] why did the fire spread so fast specialists at Montan technology in Dortmund in Germany carry out tests they're recreating Lisbon's narrow Alleyways in this fire room wooden industrial pallets stand in for the buildings of the old city [Music] distance between them Faithfully represents the cramped medieval alleys how fast will these streets Catch Fire how much time will the inhabitants have to escape the final element is wind the electric fan is switched on to replicate the Northeast wind on the day of the disaster control room to filter system Stone the fires are started at first the outbreak seems manageable [Music] but then The Inferno develops much faster than the experts predicted Flames from both sides meet in the middle the street Is No Escape Route it's a death trap maximum power maximum power applied maximum temperature 760 degrees the wind and the confined space to Ablaze into a firestorm maximum temperature in building 2 is 1043 degrees carbon monoxide level 0.3 percent and carbon dioxide 6.2 percent 6.2 is 12 times the normal level of CO2 easily enough to kill [Music] the rebel of collapsing buildings would pump out even more gas at such high temperatures the wood begins to pyrolyze and releases highly toxic gases including carbon monoxide and carbon dioxide when that happens a person can die after taking just two or three breaths no one knows exactly how many died that day the best estimate is between forty and sixty thousand one in five of the population [Music] on the Hesperides they're cruising in the area of ocean where they believe the disaster was triggered Expedition leader Valenti sayares is on the lookout for a large fault long and with a big surface area [Music] there are different relationships between the length of uh of a fault or of a single fourth and also the surface of the fault with the magnitude of the earthquake that can generate and we see that for an earthquake of the size of the Elizabeth one so 8.5 8.6 should be more than 200 kilometers Southwest of Portugal the Eurasian continental plate collides with the African and the Atlantic Plains The Faults here are long and Broad there are several possible sites where plates could shift rise and fall the four fault zones which are the most likely candidates for having produced the 1755 earthquake are the Goring bank which is a five kilometer High submarine Mountain the Horseshoe fault which stretches along this region here third the Marquez de pumbal structure but which is a bit too small to have produced the earthquake all by itself and finally here we can see the accretionary wedge which is related to an East dipping subduction zone an accretionary wedge is a buildup of rock and a subduction zone is where one plate slides under another the combination can be explosive but none of these locations has yet been proved to be the site of the 1755 earthquake [Music] the complex forces in play can be seen in a 3D view of the ocean floor the 5000 meters high Goring Bank rears above the flat Collision zone of the African and Eurasian Plains drifting over the globe a millimeter at a time the plates create extraordinary undersea landscapes like these fissures and deformations along the Portuguese Coast [Music] here at Lisbon's geological Institute they're using data from previous expeditions to recreate the movement of the plates that led to these structures it looks simple two Plexiglas sheets simulate the continental plates layers of different colored sand are laid on top though the real Plate's a solid rock when you're working in miniature sand is the best material to show how the giant forces of the earth affect each other the challenge is to take today's structures and imagine how they came into being and then test the hypothesis is a little bit like a crime scene investigator like a a normal side detective because he's confronted usually with an end state of deformation like you are in the you know that the the crime has been has been made okay and what what you are trying to do is to reconstruct the chronology of events that originated that result every tectonic movement leaves a characteristic pattern the aim of this experiment is to create a deformation that could qualify as the source of the Lisbon earthquake the sliding Plexiglas plates recreate in minutes what takes nature thousands of years [Music] if two plates Glide past each other without friction little seismic energy is created but if they get stuck or as here one is forced up or down there's a great deal of strain a massive amount of energy could suddenly be released so we know very well what happens when we have a single trust and what kind of structure we would expect from this movement like this and we also know what kind of structures to expect associated with these other kind of structure so what we we are trying really to figure out is what happens what kind of structures are supposed to form when we have both systems working together at the same time or at least interfering with each other and this is why this area is critical the the corner area between the intersection of both these structures is where you would expect this train to accumulate the model confirms their hypothesis it's not just the size of the fault that matters but whether the pressure is coming from more than one direction a combination of forces like this could have released the enormous destructive power of the Lisbon earthquake [Music] in Lisbon one man ensures the city doesn't sink into chaos [Music] the king's Chancellor Marquis pombal has won Maxim bury the dead look after the living he declares martial law plunderers and thieves are executed on the spot [Music] he creates field hospitals for the injured and tent cities for the homeless [Music] he has the church's permission to bury the dead immediately in Mass Graves unheard of in a Catholic country but essential to avoid epidemics pombal is everywhere the king is nowhere to be seen [Music] plagued by nightmares he will sleep for the rest of his life only in tents or wooden palaces he will never spend a night in a stone building again [Music] inside the city fanatical priests led by the Jesuit malagrida call the Quake the expression of God's wrong they predict the imminent end of the world origins of the flame you see that burns your Treasures are not the Comets not the Stars not the natural phenomena [ __ ] your sins your abominable sins listen to me the aftershocks continue and the fires burn on for three days religious processions thread their way through the ruins everyone Catholic or Protestant must kiss the Saints and reliquaries or be punished punished pombal will never forgive the Jesuits for their actions in Lisbon's hour of need [Applause] [Music] on the Hesperides they're cruising back along the Azores Gibraltar fault line to raise the obs's each takes an hour to surface from 5000 meters below if the anchor doesn't release on a radioed command from the ship there's no way to bring a seismometer up all its information will be lost on some previous trips the failure rate was nearly 20 percent at 25 000 a time they can't afford it yeah you were happy because this always a thriller a little bit when you have this that you don't know if it will arrive or not and once you see it in the surface then go there having it here you're happy you're quite happy but the thing is that you have to repeat this 30 times to be really happy search the rune ruin three quarters of the city is destroyed that includes the brand new opera house and the Royal Palace next door housing the king's art collection paintings by Titian car Reggio and Rubens are lost forever [Music] pombal orders the troops to clear the debris every able-bodied citizen is expected to help too no one is allowed to leave the city unlike the priests pombala is sure the earthquake was not a sign of God's Fury but a natural phenomenon and his response is just as rational he sends questionnaires to every Parish in the country to record the precise time duration and severity of the earthquake the effects of the tidal wave and the numbers of wounded and killed [Music] [Applause] this scientifically Priceless information is kept in Lisbon City Museum the documents don't just show the scale of the crisis they show how pombal uses it to become dictator of Portugal as he protects the population he consolidates his power cutting out his rivals if they don't follow his orders they will pay the consequences [Music] officially the King still rules in fact pombal is now the ruler of the king Ordinary People in Lisbon are unaware of his takeover they're just grateful someone has taken charge and given them a reason to Hope [Music] like most of the merchants Carl Peterson has lost everything British merchants alone have lost 10 million pounds in the disaster in today's money that's more than a billion is alive and his family is safe three weeks later news of the disaster reaches other European capitals stock markets crash the disaster also shakes the world of ideas there's a heated debate over the meaning of the earthquake is it a sign of God's Fury or the work of nature for the first time science dominates the argument [Music] foreign turns his mind to reconstruction no new buildings will be erected without his permission their height even the size of Windows and Doors is regulated a new half-timbering system is invented that will take the pressure off the walls in an earthquake the same principle is still used today [Music] foreign [Music] s with their half-timbered construction distribute the weight better but they're lighter than before so in an earthquake they will sway more easily if the resonance set up by the trimmers is too powerful the buildings will still collapse Tomball carries out endless experiments on model buildings oh only designs that survive the tests receive the marquis's seal of approval Lisbon soon has the first earthquake resistant buildings of all Europe pombal's greatest Triumph [Music] the expulsion of the Jesuits they have opposed him for too long preaching sermons of hate and repentance throughout the nation just two years after the earthquake pombal forces them to leave Portugal forever for another 22 years pombal is the Undisputed ruler of the country until the King dies power is in his hands alone [Music] thanks to his far-sighted plans Lisbon Rises From the Ashes narrow medieval Alleyways give way to the most modern city in the world a city of Broad Streets where every house is divided from the next by a firewall [Music] generous public open spaces places of Refuge if disaster comes again which in this turbulent region can never be ruled out the obs's have been on the ocean floor for one week in that time they've recorded all the seismic movements beneath them now their data is downloaded Europe will have to wait a while for an effective early warning system for tsunamis first all the potentially dangerous faults must be identified and examined it would be a real bonus if they can find the fault that caused the great quake of 1755. integrating all this information together gives a very complete view of the different structures that we have in the area and this gives quite a lot of information about the different sources or potential sources of this earthquake at all the spots they've identified so far the plates are shifting a few millimeters a year it'll take a long time for energy to build up to cause another great earthquake but the potential is there west of Gibraltar they've identified a major risk area this is the subduction zone it could be the one a portion of the African plate is being pushed beneath the European plate it is this tectonic motion which is the most likely cause of the Great Earthquake of Lisbon of 1755. here it is on the virtual seabed and this model shows 12 million years of geological history as one continental plate slides under another building up the accretionary wedge the horizontal and vertical movement the scientists were looking for if it caused the Lisbon disaster we're safe for the time being based on the geological evidence as well as the velocities of the tectonic movements in the area we believe that such an earthquake happens roughly every two thousand years but there's still no final proof this was the culprit and that means Lisbon is still at risk a view of Lisbon from offshore shows how vulnerable the city still is pombal made Lisbon safer in an earthquake but a tsunami today would cause almost as much damage as before a 10 meter wave would overwhelm the baisha just as in 1755. the sooner the scientists have the data to develop an early warning system the sooner the people of Lisbon and other cities will be protected from the horrors of a tsunami and the more prepared they will be to cope with the aftermath of an earthquake high above the baisha the ruins of the Campo dokamo Church still show the scars of the disaster [Music] on the morning of November the 1st 1755 hundreds of people died here when the roof collapsed [Music] thank you the skeleton of God's house is not just a memorial to the Past [Music]

Channel: hazards and catastrophes

Views: 795,864

Keywords: full documentary, full documentaries, documentary, catastrophe documentary, lisbon, earthquake, history, tsunami, 1755, earthquakes, lisbon earthquake, top fives waves, storms, inferno, Natural Disasters, 1755 Lisbon Earthquake, Great Lisbon Earthquake, Richter Scale, Historical Disasters, Lisbon history, tsunami wave, earthquake tsunami, earthquake europe, earthquake catastrophe, erthquake sea, earthquake documentary, tsunami documentary, documentary earthquake

Id: nglkbzjmSA0

Length: 49min 16sec (2956 seconds)

Published: Sun Jan 15 2023