Volcanoes and Society

tonight I'm going to concentrate on volcanoes and society and show you some examples largely drawn from my own experience of the effects that volcanoes have on society and how you manage the risks and hazards that are associated with volcanic eruptions first we just give you just a few facts and figures about volcanoes on the earth there's about fact there's five hundred fifty one historically active volcanoes they're actually about estimated at least fifteen hundred active volcanoes around the world and you'll see that the 551 is a is about a third of those in fact most volcanoes cuz they go have long periods of dormancy most about a thousand of them don't have any historic records at all and they and so it's quite a common for volcanoes with no historic records to start but RUP ting and that was Mount Sinabung in 2010 there's about 50 eruptions somewhere on the earth every year and we don't him about many of them we hear about Krakatoa of course and over Christmas but the reason we don't hear about them is that they're either in very remote islands or they're in places with very low populations and they don't really affect anybody very much and so the media doesn't really pay much attention to them over the course of history there's an estimated there's records of about 250,000 fatalities from volcanic eruptions but probably the real casualty figures are rather high the records on that good the note the economic and social costs are high so I'll show you later in this lecture and also there are large eruption effects on global climate or I'm not going to talk that much about that topic too tonight so although volcanoes there's no increase in volcanism on earth the roughly that 50 eruptions per year is still the cap beamed that the case for tens if not hundreds of years but the reason that volcanic risk is going up is because of global vulnerabilities increasing populations are growing building up towns around volcanoes there's increased infrastructure increased into dependency and they'll be I'll show you the effect of the eruption in Iceland in the UK later in the lecture where are most the volcanoes well you can see the those 1500 volcanoes on a map here of the earth and you'll see that they're very strongly clustered around the tectonic plates of the earth places like Japan the Philippines Indonesia South America so they're mostly at places where either the tectonic plates of the earth are splitting apart or in fact most of the world's dangerous volcanoes are where the tectonic plates are actually colliding and that's what's happening in somewhere like Japan ok the firt the main problem with volcanoes from a hazard point of view and a risk point of view is that there's not just one kind of hazard the several kind of hazards and this gives you six examples there are actually other ones there's something called a pyroclastic flow which is a essentially a hot avalanche of dust and rock that goes down the volcano and I'll show you some films about that in a moment there's volcanic ash itself which can go up into the sky and stop for example commercial airlines or military aircraft as well and they can also volcanic ash can form cause health hazards the tsunamis and of course that was very much highlighted by Krakatau we're a bit of the volcano because of its activity fell into the ocean and caused a tsunami that's the famous hisagi print of a tsunami and Mount Fuji and then on the bottom left there are things called lahars again I'll show some films to show you what a lahar is but basically it's a flood of mud and rock that's very commonly happens in association with volcanic eruptions and then there's explosion of course explosions violent explosions of you're near the crate and volcanic gases noxious gases can come and can cause different health difficulties or even death and then there are a LOF of flows which can burn usually don't cause casualties but of course they can cause an awful lot of destruction by burying and burning so just take gives you some examples of these some something called a pyroclastic flow and this is really in some ways we go back to Montpellier vivre volcano on the island of Martinique in the Caribbean in 1902 there was a very large pyroclastic flow which destroyed the city of San Pierre on the island and it was really almost the birth of modern Volcanology because it was such a dramatic event that the the the story went round the world and 29000 virtually everybody in the town was killed by the pyroclastic flow and you can see in the bottom right hand side the destruction it was almost like a sort of nuclear explosion almost devastating the town and then I've just highlighted that twenty nine thousand people died when political priorities take president over public concerns and it's just to make the point that it's often not the natural hazards which cause the death it's the the poor response to that natural hazard for whatever reason that causes turns a an event into a catastrophe or a disaster in the case of Mont Pele and Sam Pierre the volcano had actually been active for for a few weeks before the the main event and there were some elections coming up and there was some engineers and doctors who knew enough about science to really ask the politicians in the town and the mayor that they should really think of moving people out of the town but the there was an election on May the 10th 1902 and the politicians were very very reluctant to put a halt on the election and on May the 8th the pyroclastic flow came out they delayed their decision and that's a really a significant factor in the tragedy okay I'm going to show you now some film a film about pyroclastic flows and the hazard just to give you an idea of how dangerous these things call pyroclastic flows are one of the most deadly of volcanic hazards they are rapidly moving avalanches of hot rock dust and gas that flow down the sides of a volcano and into surrounding valleys it can climb up and over riches and high ground they are dangerous because they flow much faster than a person can run and often faster than a car so for those in their pathway there's little chance of escape what makes them especially lethal and devastating is that they're extremely hot during the day they appear gray and ashy but at night it can be seen glowing red-hot they destroy and bomb anything in their way therefore severe injury is certain for those caught by a pyroclastic flow there are two main ways pyroclastic flows may form sometimes a volcano explodes and forms a fountain of hot pulverized rock and ash that frost rapidly rises into the sky and then falls back forming pyroclastic flows which raise those sides of the bulky other times instead of an explosion sticky lava duty that a volcano and piles up around the site pyroclastic flows can then form by parts of the lava collapsing although pyroclastic flows normally move down valleys extremely hot fast-moving billowing clouds form above them which can spell out of balance this means that even people on high ground are not safe pyroclastic flows normally travel to distances of five to ten kilometres from the volcanoes summit but in the biggest eruptions they reach much more than 20 kilometers volcanoes that have interrupted for many decades or even centuries may appear peaceful but when they awaken the eruptions are often very loud and exclusive scientists can detect that a volcano is reawakening and are able to provide some warming or advise to evacuate which is the only protection from pyroclastic flows some of you may have recognized the voice of Professor Ian Stewart from Plymouth University who was the narrator there he's commonly been on the BBC on TV science TV programs so that was Peres clastic flows and clearly you don't want to be around when those happen there's an one problem with another problem I'd like to highlight with eruptions there's another French West Indian Island called - a Guadeloupe in 1976 and that's got a volcano also called that's called the Sioux Freire and in 1976 it started to show signs of a possible eruption now an actual fact not very nothing actually really happened there were a few small explosions and some earthquakes nothing really much happened but at this what we call volcanic unrest these small signs went on for about six months and there was an enormous row between French scientists on the right there's somebody called her own taz EF and on the left is a Claude Oleg and they totally agreed one said that the government should evacuate everybody and that's what they did and the other said it was a waste of time and so we get this problem of false alarms and communication so there's this big public growl and again it was another pivotal moment in the science because people didn't want this kind of public debate and disagreement between scientists to happen again and so what happened was they evacuated about 70,000 people from a town called Basseterre for three months they put them in temporary camps uncomfortable conditions and and then eventually they returned to the town but that three or four months of course of being evacuated and their lives being disrupted was a normally stressful nobody died but it did then seed a lot of distrust and scientists and if you go my colleagues from France who go on the island and even nowadays many people student don't trust the scientists and the government because of this episode so this is another difficulty that volcanoes will often show signs that they're going to erupt and they don't and this can lead to a force of what's called false alarms you evacuate everybody and nothing happens now like to go onto another case which illustrates the terrible terrible tragedy one of the biggest of the last century it's the lahar at al mero in colombia 1985 it's a town which is about 45 kilometres from the from the volcano nevada still rez and this volcano has got a glacier on it nice cap and when the eruption started you've got pyroclastic flows like you saw in the film but they landed on the ice and because of hundreds of degrees centigrade they made the ice melt and that created an enormous flood which went down the valleys of the volcano and gathered trees and rocks and stuff and then flooded into the town and 25,000 people 33,000 people were were killed and again this wasn't this was a communication issue there was not people the scientists realized that there was a problem but there wasn't the communication mechanisms or structure to give warnings to the people in the town and again for the Colombians it was a huge tragedy and they were determined not to do anything have that happen again in fact Colombia's one of the world's best sort of Volk and monitored countries in terms of volcanoes the scientists they are excellent and since then they've had many eruptions but very few deaths but and it was really the response to this tragedy okay so what is a lahar where again I'm going to ask Ian Stewart to explain that to you [Music] a major danger on many volcanoes comes from floods of water mixed with volcanic debris these floods are called la house la house are more destructive than a normal flood because they contain large amounts of rock ash mud and deadly Boulder swept along by the llaha can sometimes be the size of a car they can form very quickly and flow down the volcano into the surrounding valleys often at high speeds several lahars often occur in quick succession lahars are a major cause of death and volcanic eruptions they can travel great distances many kilometers or even many tens of kilometers so communities far from the volcano can still be in great danger there are many causes of lahars a very common cause is if this heavy rain an eruption can cover the sides of a volcano with loose rocks and ash vegetation and soil is normally absorbs the rain and prevents floods can be destroyed by the eruption adding to the problem when it rains heavily brought ash and debris are easily swept into the water forming lajas the rocks and debris give the lahar extra destructive energy and often the flows move much faster than someone can run some volcanoes are covered in glaciers and ice or snow eruptions of hot rocks can melt the ice or snow rapidly to form boss of huge volumes of water that form lar house lahars can occur at any time during a volcanic eruption but they can also happen many years afterwards fortunately there can be warnings given about Lars if heavy rain is forecast then the chances of allaha increases for those places threatened evacuation is the only option if there's not enough time to evacuate then people can protect themselves by immediately leaving valleys and going to high ground hating and buildings is not safe as large lahars can destroy buildings flow into them but the upper floors of a strong building may offer some protection if there's no alternative okay just to say that that hopefully gives you an idea of what a lahar is which is because the eruptions destroyed the vegetation and put a lot of debris on the volcano and when it rains hard you can get these terrible floods full of rock and also when there's a glacier these films by the way you can download for free that you can get them on the internet on on Vimeo and they're really designed to help communities understand hazards and risks that they face and we've now got these films in six different languages okay so let's move to another case this is in some ways a better story than the previous ones in that we now move to 2010 and the eruption of the volcano Merapi with in November 2010 the were 350 people killed and that of course a tragedy but it could have been unlocked lot worse and it was because the scientists were monitoring the Indonesian and us scientists were monitoring the volcano very well that they decided that they would evacuate about 4 hundred thousand people and they did that evacuation over several months and they it was good that they did that because they'd they'd they'd seen that the volcan the pyroclastic flows from the volcano could typically in previous eruptions have gone about ten kilometers but the volcano was behaving in a very unusual way and their interpretation was that they were going to get a very big much bigger eruption and so in fact that you can see that gray area in the valley there that is the pyroclastic flow where it went down a valley and in fact went 20 kilometers and went through quite a few villages and the estimate is that if they'd had not evacuated the death toll would have been about fifteen or twenty thousand people you're in these situations you're always going to get a few people who stay behind for whatever reason don't take listen to advice and of course that results in the in of course that terrible that three hundred and fifty people were killed but it's sort of all in this sort of situation almost inevitable and the result I think of this was a success in the sense that probably fifteen or twenty thousand people were saved and that's the the vit just some pictures of from this I went out there to get involved in the study that's one of the villages on the up top left where there were few people who stayed behind it's quite socially it's quite interesting that actually it tended to be the men and the young men and young men who was and sort of if you're like adolescent boys who were killed preferentially because the white the the family would be evacuated they're sort of young children and the the old people in the and the the wives and so forth but the men felt it was important to go back to their houses to see if they could rescue other goods or look after their livestock and so some of those did go back and were tragically killed you can see here sort of rather unexpected this is a dam which is to prevent floods into this village but this dam cause more destruction so you can do one thing to sort of save yourself from floods but what happened is the pyroclastic flow hit the dam and went sideways into the village it was only because the dam was there so you can sort of do one thing and there's an unintended consequence the world lahars and again you can see a lot of debris there those are from the lahars and then you can see the evacuation camps that the Indonesian government had to put up so the so this is about two or three months afterwards there's still 20,000 people evacuated in in camps so going on to another case which again where we could we get some politics coming in it's an intriguing one there's a volcano and called columbic gal heiress and southern Colombia quite close to the Ecuador border and it's got a big city called pasto of about 400,000 people and over the last 10 or 15 years the volcano has been having lots of little eruption and some of them are a little bit bigger not very big but the Colombian government decided on a policy which is very controversial of relocation and if you look at where pasto is on the map you'll see that there's a series of small villages which were populated by indigenous people and the government decided that they would not just evacuate those villages but they would completely depopulate them they would relocate those people to other parts of Colombia and as you can see on the bottom right of the two pictures of the the local people they didn't think this was a very good idea at all and participated in town meetings where they were saying well we've lived here hundreds of years and not even a dog has been hurt and we don't think we think we know the volcano and then since they were there they were right and they rebelled and they refused to be evacuated and eventually after of several years actually the Colombian government sort of decided that they wouldn't go ahead with relocation but that's another kind of if you like there was no tragedy here but clearly a lot of concern and worried by the local people that they were going to be asked to leave their villages so we now go on to perhaps the most contemporary big volcanic event which was Krakatoa in December 2018 I think probably most of you in this audience would have seen seen that and of course again another tragedy because there were lots of tsunamis I just want to show you what some of the activity in December 2008 teen this is a volcano which you may you may know there was a huge eruption of Krakatoa in 1883 which formed a giant crater and a new volcano started growing in that crater almost immediately and it came the crater was under water but the new volcano grew above water and formed a new island and you can see some of the intense activity so this was a new Island building up in the in the in this ocean and on the left-hand side you can see a satellite image of the 21st to December it's about a couple of kilometers across the volcano we can see it from the sky and the main thing about a volcano is it's basically as a big unstable object and volcanoes are prone to having big landslides so another hazard that volcanoes posed as simply being a big unstable mountain and it's a big unstable mountain in the sea and if it goes active then that's that can be a trigger for instability and that's basically what happened and if we look at the before on the on the left and the after you can see that that big cone that Bay is about almost it will probably about seven or eight hundred metres wide the volcano has disappeared because it slid into the sea and pushed the sea away and that was the cause of the tsunami and the the reason the tsunamis of course people can get caught in the tsunami but it's very like lahars in some ways the tsunami wave comes in land then get and you've probably all seen films on the telly of this it grabs almost anything in its way buildings cars bits of wood anything and then the water flows back with all this debris and once it's gathered all this Debra it's a bit like Allah high it's very destructive and that's what happened in Krakatoa there was no tsunami warning system in operation by the Indonesian government at that time they did have one but it wasn't working and so if that had been working then the coastal communities would have had probably maybe twenty minutes half an hour warning do to retreat and basically go uphill so tragically there again it so you could see that's a human often disasters are caused by humans not by the really by the volk volcano in a sense it's that the fact they didn't have an adequate an operational early warning so I'm now going to go to my favourite volcano which is in the Caribbean when I've done an awful lot of work on over the years and been to many times it's called Montserrat it's a British dependent territory sits quite close you can see on the map quite close to Antigua it's a mountainous mount Ireland with a sizable volcano or in the southern part and the before the eruption that started in 1995 it was a lovely Caribbean island with about 12,000 people living on it it had never had an historic eruption we don't we know the last eruption must have been in this 16th or 15th century so nobody had any experience of volcanoes but the volcano began and you can see that it's got all this gray material this is taken in I took in 1997 that that grey mound is the lava flow and that Delta of grey stuff is the basically the pyroclastic flow fan and there was a sort of a bit of a joke this is the first time the brick fitted since probably the beginning of the 20th century that the British Empire had grown by about a square kilometer because of this new land that was caused by the para clastic flows going into the sea its pyroclastic flows were the danger so the net result of the eruption was that the southern half of the island had to be evacuated the town of Plymouth was destroyed and those gray on the maps are where the para clastic flows that you saw in the film have gone down valleys who could see that basically the southern half of the island is really was really too dangerous for everybody anyone to live and so it was an enormous tragedy in a social setting in a social sense the population reduced from 12,000 to 4,000 not because anybody died but because the island was too small to hold that population they didn't have the facilities so many people came to Canada the United States Britain all round other Caribbean islands and they had to basically leave so there's an enormous sort of evacuation of the people of the island also the worst some people killed gained a similar problem but although the area was officially evacuated some of the best farmland in the island was on the on the north side of the volcano and you can see on the map on the top left where the pyroclastic flow of the 25th of June 1997 went you can see the size of boulders that that pyroclastic flow took down the valley and then you can see the hot that the cloud of hot ash over houses formed by the pyroclastic flow it it was going moving so fast it went a hundred meters uphill now unfortunately a number of farmers had gone back to again look at ten their crops look after their their livestock and so forth they were living in very you like shelters at the time and so it wasn't really a surprise that some people would want to come back and take the risk so the worst some tragedies but again rather like Merapi I think the the overall story is that a lot of people's lives were saved by the evacuation and the monitoring this is some pictures of Montserrat on the top left as the pit as the tower beautiful to Old Town of Plymouth unfortunately completely buried under pyroclastic flows on the bottom left is the hospital which the British government spent something like well a lot of money on anyway that was the new hospital which has destroyed I receive invitations that this Plymouth was very vulnerable and so the net result was some 9,000 people relocated there were 20 deaths the estimate this is back in 2003 is that there's about a billion dollars of losses economic losses and ever since then the island hasn't been self-sufficient unfortunately and so it's costing the UK's taxpayers and overseas dependent territories costing us about 30 million pounds per year to keep the the island going so it's cost the UK government a significant amount and that those costs are still being accrued just a story of my own that was while I spent part of the time in the first three years of the crisis as the director of the observatory a new Observatory and this is a bit of a cautionary tale on the the the two photographs are of this of the southwest side of the volcano and you might have you've if your eyes are so it's good to see somewhere called go aways estate and these pictures are looking at the volcano from about there and the picture on the left you can't really see this but there's actually a picture of an earthquake there was an earthquake going on and lots of that war was sliding away and the lots of the ground was cracking up on this side of the volcano and we were very worried that there would be a very dramatic violent eruption this is October 1996 and people were evacuated from these areas to avoid this problem but actually nothing very much happened for quite a long time the war was clearly unstable and clearly there was potential for a big event but of course nothing happened and the local people would be sort of to talk as you in the street saying I as you scientists don't know what you're doing nothing will happen so 14 months later I was chief scientists of the director of the observatory over the Christmas period and that was I went up to the same place 21st December 1997 and we looked over and we can see we can't see that wall anymore because gray larva and stuff volcanic debris has buried the wall so we still thought this was pretty dangerous non Christmas day we were having a party in the observatory when the seismometer started to go and they really started to go and we realized something was a myth and then the very next morning after Christmas didn't have we went out and we found basically total destruction of that side of the volcano what you're looking at perhaps I can just draw your attention to to the the bottom right picture you can see that's an area where the villages which are there have completely disappeared and that's because there was a pyroclastic flow that went to all around this area at 300 km/h and just wiped absolutely everything out if anybody had been there they would have not survived so that that's was the but what we call the Boxing Day event and it was very dramatic and so what we'd been fearing did actually happen but it happened 14 months later okay just to show you living with a VOC how the monster ations lived with a volcano this is what we call the zone is a small island and there's a quote here that somebody a famous quote that somebody on the island said this island is exactly the wrong size for an eruption and the reason they said that was that if it was a much bigger island it would have been very easy to have accommodated the people who were evacuated and put them somewhere else on a big island it was a smaller island then you would have had no choice but to totally evacuated but the monster ations are pretty resilient people they wanted to basically carry on living in the top third and you can see some of the the ash that was produced which made life unpleasant you can see one very creative guy put his house on a truck and took it to the north and then you can see a great I think a great picture for these sorts of event there's a big explosion going on in this guy who's completely ignoring it because by this time two years into the eruption they were used to explosion - they wanted to get on with their life and I remember going to the cricket ground on the island to watch a cricket cricket match and there was some spectacular explosions going on in the volcano and I was with my scientist friends we were all watching the volcano and all the locals were ignoring it and playing cricket getting on with their cricket game because they'd got used to it so it's a it's amazing how resilient people can be - to an event of that kind and then we later in the eruption we basically have made it run a much simpler management map concede the red area nobody could be there and there's the northern zone where people could carry on with their lives and the monster ation people could build up there the island again okay just a little bit about the the some of the work that we did with the UK government and the monster Asian government and the mat crisis management we formed a risk assessment panel which I chaired for many years and its job was to assess the hazards and risks to the volcano every six months used observations and models and something I'll tell you a little bit more about expert elicitation our output were reports and risk charts and discourse discussions with people like the governor and the the prime minister of Montserrat and UK ministers back in Becker in the foreign office and we reported the risk in terms of chief medical officers scale and analogies similar to the public and so we were there sort of basically the committee or panel which gave the advice and the eruption I should say went on for 15 years so it didn't stop in 1996 71 it went on till 2010 so it was a long-running emergency and we developed sort of some fairly novel methods which is essentially something called expert elicitation and it's quite entertaining to talk about it but I think it's got a serious side so what you're interested in and if you look at the words that we've got this questions what's the chance of a major explosion in the six months what's the chance of the village six kilometres northwest of the volcano will be affected by prioritizing flow so these are the practical things that governor's and Chief Minister's and services want aid protection services want to know where are the dangerous places and so what we did was we had a panel with our colleagues from the University of the West Indies and we did something called expert elicitation and I'm going to perhaps not to look at the slide for a moment and I'll just talk you through this if we have a typical response we have a committee we we get a committee of experts and they all say their things and they try to come some sort of view but the truth is that most people are very varied and how expert they are and if you're trying to forecast the future then there's a lot of uncertainty and we wanted to capture that in a methodology so what we did was we calibrated the people on our committee including me and so how good an expert were you and this is an example let's just go back if you look at the I'm got a pointer unfortunately but look at expert one and the little arrow is meant to be the right answer and I'll give you an illustration let let me ask you the question how many litres of red wine to the French drink did the French drink in 2018 okay that's your question and some of you may be experts because you go on holiday in France and drink a lot for red wine some might be great experts because you are a wine merchant and you know all about the statistics of French wine and so forth so it's add our question but it illustrates the sort of questions we asked our experts to see if they were any good or not and so a good expert that the arrow is the real answer an expert one gets it spot-on but more important they've got a spread they're asked to say what's the most it could be and what's the least it could be so that person got it right expert two got it right that expert got there but they've got a very large spread so it's like saying how much red wine did the French drink and you say well anything from 10 liters to a trillion liters and you know that the are right answer must be somewhere but your guess isn't very informative there's not a very helpful guess but if you're very precise you said it's exactly seven million three hundred and forty two thousand six hundred eighty five liters with very little spread and you get it wrong in a hazard situation that could be a disaster because you've made the wrong you you you were too confident in your expertise and then there's a bali there's somebody who doesn't even get the right aren't so in there obviously not so good and you can plot i won't say what these parameters are but in the chart these are parameters which basically say how a expert people are how much they know and how good they are at judging uncertainty in the net in many circumstance and so to the more to the right you are the better you are and the problem is if you look at the numbers each each number is an expert experts one five and nine are pretty good and expert eighteen is not very good at all but the numbers are the rankings of how you know if you like their esteem if there are an esteem professor then or they might be a a young student and you can see that number one roots indeed the top expert and does very well look at number two that's your opinionated person on a committee who thinks they know everything and then and they don't they don't know nearly as much as they think they do and so what we do is we use that to run our risk assessment we had a real situation in 2003 when the volcano was very dangerous we were worried about the pyroclastic flow getting to a particular village on the Left there's a map showing you where that villages there were several hundred people there and on the basis of our estimates we we evacuated the village now this is a bit um frayed a bit technical on the left it's a what's cousin surance people use it's the probability of a number of people being killed and a certain number of P period against the number of fatalities and so what you do is a risk if you're at a risk curve the red one basically when you if you keep the people in the village they're very vulnerable the risk is very high and you've got a one in ten chance of a really you know tragic situation if you evacuate the people out of the village then you get the next gray curve and then it goes to one in a hundred and then if you go down to the other green gray curve it goes to one in a thousand and the risk is is okay and the blue and the green are the risks of being in the if you live in the Caribbean of being a fatality due to an earthquake or a hurricane and so we could be reduce so we don't want to take people too far away because they've got to get on with their lives so what we did was we got them the evacuation zones so that the risk reduced to the same risk that they faced as a consequence of living in the Caribbean from hurricanes so that's how we use that and what happened well when we did the risk assessment this is the volcano on July 2003 we thought the most probable thing was all that stuff just like in Krakatoa would slide into the ocean to the east and that's what happened the whole mountain disappeared into the ocean we also got a tsunami on that day so the risk was reduced there wasn't a dangerous mount in there anymore so the people could be go back to their homes ok I'm going to go through this last one fairly speed leaf herb it's the last case I'm going to deal with it's probably the one a lot of people in this room might have been affected with is the 2010 eruption of a volcano in Iceland in the summer 2010 when as I think everyone knows the air blinds were had to be shut down over Europe I was involved with the the National Committee were with people from all sorts of different organizations in order to give advice during that period and Iceland just to say that I think the headline figure is here the eruption there's an eruption on Iceland every 50 years and this one wasn't a particularly big eruption that bottom on the right hand side you see the eruption which calls the problems so quite a small volcano it hadn't erupted since 1821 so nobody thought it was very likely to erupt in fact there's another volcano in Iceland called Katla that people think might much more likely they thought was much more likely to erupt so this little volcano erupted in March 2010 tells you a little bit of the history and it's those week expose of eruptions on the right in April May that stopped all the aircraft in in Europe and so why did that happen we got a combination of a small volcano which erupted in a glacier and the explosions broke up the lava into tiny lots of tiny dust which could be transported a long way and unusually the wind was blowing to the south this stuff usually goes over Scandinavia and doesn't cause us any problems but we were unlucky but the wind was blowing south and so what happened this is a satellite image of this eruption and the the yera the reds and greens and so forth at different times are showing you the spreading of this ash cloud over so wherever you see greens and red there's a lot of ash in the air and you definitely can't fly through it and I think that the tooth the main thing I want to just emphasize is just how quickly this stuff spreads up over the entire part of Europe very hard to predict and also quite complicated patterns that's makes it hard to predict so people couldn't really the ech Europe is the busiest air traffic in the world pretty well and you couldn't really you really couldn't fly in the aircraft if the if people thought this ash was going to take so let's have a look at a movie from some of my colleagues at Bristol who've been running computer models of the spreading of the ash so here's our eruption and this is their computer model showing you the ash this is probably about 12 hours of activity something like that the ash cloud spreading in a complicated way over Europe and that's really why the planes had to stop the problem was that if you get some of this ash in an aircar in an engine the engines are known to stop and there's a famous British Airways flight going over Indonesia where all four engines stopped and there was almost a tragedy but one of the engines when they got to 5,000 feet and thought it was that was it one of the engines stopped and a British Airways pilot managed to land the aircraft so ever since then people have said let's just avoid this stuff we won't fly through it at all so when the ash came over Europe there was that wasn't that what really wasn't an option just to show you that the met offered some of the work the Met Office do it Chilbolton and just to show you just north of Southampton this is something called lidar basically it's a it's a way of imaging the dust and the atmosphere and this is that with time the if you look at that green squiggle they basically the between the the Earth's surface and of three kilometers there was an enormous amount wherever you see it green there was enormous amount of ultrafine dust over southern over southern Britain so just shows you how far this stuff got and this is just something you can download from the internet it's a great movie it's the 24 hours of flights around the world in one minute and I've just got a snapshot unfortunate it's not it's when North America win there's no flights over Europe because it's the middle of the night but you can just see the each yellow dot is a flight an active flight and you can watch these yellow dots go all around the world and realize just what an enormous issue it is you can even see the Mexican border over the United States from this but it's when you've got that enormous crowding and the possibility of a tragedy from ash injection that you'll go so what happened grounded aircraft for six days probably twenty million dollars a day a billion those few days a billion dollars it's probably even is significant political fallout and travel disruption insurance claims so a huge amount of damage I think I'll miss that one out oh it's re just I think I'll keep this one in just to say that now the world has nine new areas where there's a meteorological offices in each of these areas which their job is to forecast where volcanic ash remember I said there were 50 eruptions a year so this is happening all the time so Met Office the Met Office controls what we call the London vac Toulouse controls the sort of a very big area and these these people's job is to tell you do those computer models and tell you where the ashes going and stop there either make the aircraft avoid the ash or whatever so just to say last couple of slides now the it's who is a very interesting episode because in viruses environmental protocols and standards which have been going on for twenty years which is basically you avoid the ash were changed overnight and they were changed overnight by people like Willie Walsh and so forth who were saying we're coming in even if there's ash and our engineers say it's okay and so the twenty five flights coming in over that weekend when they that they shut down and I think it's lauded donis and his group decided there'd open the skies again but it was a very hard decision and basically an environmental standard was essentially torn apart overnight it challenged international practice as to say operational responses changed in a weekend and there was some sort of it still really a very unclear there's a lack of transparency basically the engine manufactures looked at their what happens when very fine dust gets in their engine and they concluded it was okay to fly in small amounts of ash the the rule was who didn't fly in any ash at all and they don't never really let their data out they still haven't because if Pratt and Whitney or rolls-royce say well my engines not so good for ash and published that data and their their engine isn't quite as good as Pratt and Whitney or vice versa then that's got huge commercial implications so they never really published the data on which the basis of opening the skies game there were some lessons learned it was complex decision making decision prior decisions primarily drained by a computer model of the kind I've this is the Met Office model that's just call name there's a computer model to say where the ash is going the lots of different organizations UK government department for transport Chris Grayling wasn't the minister at that time the CEA and European partners so there was obviously lots of governments around the world and these are all these all these acronyms you don't really need to know like except the lots of different people have to get involved engine manufacturers Airlines transport ministers civil servants scientists like myself passengers insurance industry and an awful lot of actors involved and Britain didn't have volcanoes on their national registries because everybody knows Britain does have volcanoes but it's now as a consequence of this is now on our national risk register which is updated every year and there's a print now system which in 2011 actually worked much better when there was another small eruption in Iceland so hopefully this sort of tour of different volcanic emergencies giving you some flavor what volcanoes can do and I'm happy to take some questions thank you you

Channel: Gresham College

Views: 5,988

Rating: 4.8441558 out of 5

Keywords: Gresham, Gresham College, Education, Lecture, Public, London, Debate, Academia, Knowledge, stephen sparks, Geology, volcanoes, society, active volcano, eruptions, Eyjafjallajokull, hazard assessment, Risk Management, Soufriere Hills Volcano, Montserrat, volcanology

Id: xLfTaHACHHg

Length: 51min 33sec (3093 seconds)

Published: Mon Mar 11 2019