Participant #1: One question, four expert witnesses. Welcome to the inquiry from the BBC World Service. Our podcasts are supported by advertising BBC World service. This is Neil Roselle with the inquiry. This week, can we earthquake proof a city? Participant #1: The top tauwanese city of Tainan last month. In the moments after a quake, Participant #1: rescuers face an urgent and dangerous puzzle. It's dark. Their torches show rubble before a building badly escue. They throw ladders against it and climb in. Participant #1: When floodlights arrive, they reveal startling damage. A 17 story block of flats has collapsed onto its side. The concrete floors are in a herringbone pattern. Hundreds of people are trapped. And across Taiwan people are hoping the same thing doesn't happen to them. It was about 04:00 a.m. And I woke up with a start. The entire building was just shaking very violently, it was quite loud and I honestly couldn't tell you how long it lasted. I just remember thinking please be done, please be done. As quakes go, it wasn't even that powerful, magnitude 6.4, but it left buildings leaning precariously and 116 people dead. They add to a toll of almost 1 million dead in earthquakes in the last 20 years. Is such death and destruction inevitable? Or as we're asking this week, can we quake proof a city? Participant #1: Part One lessons from the Dead Participant #1: earthquakes are most likely to happen in Southern California, Indonesia and Japan. Dr Emily So of the University of Cambridge in the UK. There's the Himalayas in Nepal as well. And Haiti. Tehran, a city which is highly prone to earthquakes, have now over 9 million people living in that one city and is dumble as well. She's perhaps the leading authority on earthquake casualties and says buildings are the biggest killers. I'm trying to establish the causes of death, so there are different types of buildings around the world and with each of these buildings that the collapse mechanisms are different, dependent on the roof types, the type of environment, and it's these kind of subtleties that I want to capture with my surveys and my work. Knowing how buildings fail is crucial to making them more resistant in the future. It's important work. I'm a civil engineer by training. I was watching the news. Officials in Pakistan say a whole generation has been wiped out by the devastating earthquake. Aid agencies say millions and are homeless and in urgent need of shelter and clothing. Pakistan 2000 and 586 thousand people died, mainly from collapse of the building. Participant #1: We have yet recovered almost two dead bodies yet, but we are hoping to get some alive people in Shala. In Shala. And the frustration in that we know how to build against collapses of buildings and prevent these deaths was really the motivation behind the work I'm doing now. Participant #1: Two months after that quake, she was in Pakistan in the midst of the wreckage for the first time. It was like something that you probably only really see in movies. So lots of rubble on the ground, devastation everywhere you look. There were hardly a single building that didn't have any damage to it. So quite a terrifying scene, really. It was a very emotional time for me, actually. I will always remember that. And I think that's, again, a critical moment for me in terms of dedicating. Now, ten years of my research on this topic. In those ten years, she studied quake aftermath in Indonesia, Peru, China, Italy, Japan and Samoa. She figures more than 200,000 people have died in those quakes alone. And in the developing world, she's noticing a disturbing trend. The population are very keen to use modern materials like concrete, but they haven't got the skills or necessarily the money to build them properly. So they have the aesthetic of concrete, but not the actual material of an engineered concrete building. And therefore, when the earthquake strikes, it just becomes dead weight and it falls on the people inside. These buildings then create the illusion of security, but it's just the opposite. Yes, I would agree with you there. Her work shows definitively that design matters. People more likely to die in bad buildings. The quality of the housing is going to be different depending on whether it's developed or a developing country. As an example, in 190 99 there was an earthquake in Chichi in Taiwan. It was a 7.6. It killed just over 2000 people. And the same magnitude earthquake, 7.6, happened in Kashmir and Pakistan in 2005. And this earthquake killed over 86,000. Participant #1: Perhaps even more startling is this. She says the risk of death in an earthquake is rising. I would say so, because of the urbanization we are tending to build in the cities more and more, and in more hazardous regions, the density of the population is making the issue more prominent. So building safe buildings is becoming more important as people crowd into cities. And our next expert witness is trying to take that idea to a whole new level. Part Two high Tech City Participant #1: I'm David Mullat, I'm an architect. He's built some of the world's tallest buildings. Tall buildings, because they're tall, are somewhat inherently more stable in an earthquake. You heard that right. He says extremely tall buildings are safer than low ones. In an earthquake, the ground shakes, okay? And that ground shaking might move back and forth at, say, something like half a second to two and a half seconds. Now, a building, depending on its height, will also have this natural frequency to it. Think of a building's natural frequency in terms of a guitar. The strings are buildings. If you pluck a string, that's an earthquake. Pluck it once and the string will vibrate back and forth. Pluck it again and the string will vibrate more. Participant #1: And if you were able to synchronize your plucking with the string's vibration, it would go into something called resonance, a dramatic increase in the string's vibration. So when the ground shaking and the building swing match up, they go into resonance. And that's where we see these sort of catastrophic results. Right. Because the swings overlap in a way. Correct. And so what we actually find is, inherently, buildings in this low to mid height range are more susceptible to ground shaking, whereas a building which is a hundred floors tall, ironically falls outside of that frequency of the earthquake and therefore doesn't go into resonance. David Malot has personal experience of the need for earthquake resistant buildings. I was born in Japan. You'll probably go through an earthquake every month or so, something that you feel more noticeably maybe once every few months, but certainly as part of I would say it's part of everyday life in Japan. Participant #1: These little thumps show just how common they are. Each one denotes an earthquake. Under Japan, the frequency shows several a day. Most are harmless. But on March 11, 2011, japan was hit by one of the largest quakes ever. It brought a cascading hell, a tsunami, a failed nuclear power plant, and 18,000 dead. Participant #1: And it's here that David Milot wants to build the mile high tower. A mile high? Mile high. And so in kilometers, that's about 1.6 km tall, which would be roughly double the height of the world's current tallest building. Got somewhere up to 250 floors. Wow. And how many people then would be there at any one time? 50,000 people. A city in the sky. Then Andy says safer for it. I've been working on tall buildings for 15 years now. The first one I had completed is the Shanghai World Financial Center, 492 meters tall. And when Shanghai shook during the deadly Sichuan quake of 2008, it hardly moved. And we have sensors on the building then. I think even during this earthquake, the tower moved something like a meter at its top. That sounds like a lot. Sounds like a lot. But when you consider that the building is 500 meters tall, it's actually very small amount of movement relative to the height of the tower. It sounds almost like a bit of kelp dangling in the water. That's an excellent analogy, and I've heard the willow tree as another example. So there's something to these towers being very flexible. So modern skyscrapers have several advantages over low rise buildings. First, they're less likely to go into resonance or the kind of catastrophic shaking that can turn lower structures into rubble. Second, they demand the most advanced materials and design, which cost a lot of money, and no one wants to see that reduced to dust. So these megastructures are tested at every stage. These buildings are designed to last for 100 years, perhaps 200 years. So the kind of investment that you make in designing the structure, in performing these tests, it's a drop in the bucket compared to the initial cost of the building. Participant #1: So can we earthquake proof a city? David Mullat says when it comes to highly tested, highly engineered megastructures, we can. He's confident that his mile high dream for Tokyo will be built. But he and our next expert witness would agree there's more to a city than skyscrapers. Part Three low Tech City Participant #1: we can calculate a complete skyscraper in Japan, but we still cannot calculate an Earth in Martin, India. There's quite a bit of information missing on how a low tech building behaves in an earthquake. Architect Martin Skildcamp founded a charity called Smart Shelter to strengthen cheap housing. Do you think it's possible to earthquake proof a city in the developing world? If you have a lot of money, yeah. But there's not a strong lobby behind it that can invest and and do all that testing because the investment will never be returned. So for those reasons, there's still a lot of information that is sort of guesswork. And for me, I said, enough is enough. It's 2016, we should be able to find a number of people that can do it now properly. For him, doing it properly involves two things. One is sharing knowledge. For instance, he's built schools in Nepal using quake resistant methods. One important element is a number of horizontal beams that hold the walls together. We call it tying up your building like a present. And this combination of very simple techniques, this is what we train over and over and over again. It's sort of repeating, repeating, repeating. Supervision, supervision, supervision. But it works. It really works. Have they actually been tested in an earthquake last year? During the earthquake, our buildings survived without a scratch. They were about 70 kilometres away from the epicenter, so relatively close. In all fairness, we have to say that the region where we are was not as severely hit as, for example, Kathmandu Valley. At the same time, I'm very much convinced that our schools would have done very well in Kapmandu region as well. But, yeah, they have been tested. The second, and perhaps more important thing he's trying to do is solve a mystery. One you see when you drive through neighborhoods hit by earthquakes, you see that there's houses collapsed and they look like they have been built the same. One house is completely collapsed and the neighbor is still standing strong. So then you really don't understand what is the difference here. To answer that, he established a research network to find out how to improve the most commonly used materials. Stone, wood and bricks, for example. We see them all over the world. So if you can figure out at least those basics and then with a little bit of tweaking on the local level, I think we can go a long way. He says to quake proof a city, we may need to use old materials in new ways. So for Nepal, for example, I do see the benefit of building with gabian boxes, which is woven nets, steel nets, which we fill with stones. Right, so these are like cages, metal cages filled with stone. Yeah, exactly. And the ideas. Then rather than stacking them next to a sort of a mountain, they say, now let's stack them into walls because then we don't need cement, which is very scars and expensive there. So we have now two students working in Bologna in Italy. They try to figure out if indeed we can make those gabium boxes earthquake resistant. They're not yet sure this will work, martin says even if it doesn't, at least they've ruled it out without hurting anyone. Well, what I see now is that there's a lot of, let's say, experimenting in Nepal, where people are building with sandbags and straw bills and plastic bottles, and then their justification is that it should be quick and cheap. And I absolutely am against it. What I call it experimenting in the backyard of people that basically already lost their house once. It should be done in a safe environment in a university where we first figured out exactly how it works before we going to consider building these with thousands at the same time in villages in Nepal. It just doesn't make sense. So can we quake proof? A city ardent Schildkamp says poor countries can do better, that we don't yet know enough about the most basic structures to make them quake proof. Our focus so far has been on buildings, the highest and the humblest. Our next expert witness takes us beyond buildings to perhaps the greatest challenge of all. Participant #1: Part Four Lifelines Participant #1: Stopping all earthquake damage is an insanely expensive process. Stopping enough that you can keep your society functioning. That's very, very doable if you're willing to put in some time and effort. Listeners in Southern California may know this voice. They've been hearing it since the early 90s in the immediate aftermath of tremors and quakes, calmly explaining what's going on. I did a couple of interviews carrying my sleeping one year old son, and it sort of changed my public image, where people would say, you're the one who always brings the kids after that. Her name is Dr. Lucy Jones. She's a seismologist with the US Geological Survey and a giant of the field. She thinks few people appreciate just how bad a big quake could be. So in 2008, she organized a massive effort to change people's perception of the risks. It's a sunny morning in Southern California. Across the region, 7.5 million people are busy at work. Several hundred thousand of them are. It included this video, part of a PR campaign. But at the heart of the effort was science. A detailed simulation of a 7.8 magnitude earthquake along the San Andreas Fault. Today, these families and many others across the region will be separated. Participant #1: It's 10:00 a.m.. The largest earthquake to hit Southern California in modern times has just begun. Some people react appropriately, she says. This is what happens in her scenario. So the sedimentary basin of the Los Angeles basin acts like a bowl of jello and traps the energy and the strong shaking in downtown Los Angeles goes on for 50 seconds. But there's a wide part of Southern California that gets affected. So first you take out Palm Springs in what's called the Coachella Valley, ruptures up through Cajon Pass, which is where most of the lifelines for Southern California come into the region. Lifeline is like what? Like freeways, railways, natural gas coming in, petroleum products from the refineries of Los Angeles going out to Nevada and Arizona, electric lines and water lines. And so when the gas line breaks, there's a petroleum pipeline that's breaking at the same time in the same location. They explode because you've got them in the same place. They're very near one of the major freeways and the main railway line going out from the port of Los Angeles. So all of those are going to be disrupted. We have an electric line nearby to make sure we can set off a fire. The fire then will probably burn for a week or two because there will also be fires starting in the city and all of our firemen are going to be fighting the fires in the city and we're just going to let the wildfires go. So not a good day for Southern California. And the scenario isn't over. It continues. To look at the aftermath. We've got to try and keep many different pieces functioning well enough. So, like water, we know we're going to lose a lot of water. How much of Los Angeles water crosses the San Andreas Fault? 88%. And how much of that will be usable after your scenario? None. Her simulation has terrified a lot of people, people with power. The mayor of Los Angeles brought in Lucy Jones, and last fall they pushed through a mandatory retrofit or strengthening of vulnerable old buildings. There's a style of construction that was popular in the for our commercial buildings called nonductal reinforced concrete. There are 1500 of those buildings in the city of Los Angeles and thousands more in the region. And probably ten to 20% of them would be collapsing under strong shaking, and their concrete is heavy, so the largest number of fatalities are expected to occur in those buildings. We're mandating retrofit and we're talking about billions of dollars having to be spent on existing buildings. And we were able to talk the business community into supporting this because the business community concede that their investment is at stake here. Her scary scenario has also encouraged engineers to begin reinforcing the water lines and to look at ways of using seawater to fight fires. And today, millions more people take part in earthquake drills than did even a few years ago. So there's a lot of very positive things that are growing because of this. And if we just can hold the earthquake off for long enough, I think we can turn it around. I don't think I'm going to earthquake proof Southern California, but I really do think that we can get enough pieces in place that we can keep it going. They'll need luck. Southern California generally has a major earthquake every 150 years. The last big one was 300 years ago, so they're due. Participant #1: Can we quake proof a city? Probably not. Our expert witnesses have said it would be too expensive. But they've also said that where money is spent, the dangers of quakes can be greatly reduced. The irony is that in the places where most lives are lost in the developing world, the least is known about saving them. And with more and more people crowding into poorly planned buildings in earthquake zones, the problem is only getting more urgent. Participant #1: This edition of the inquiry was presented by Neil Roselle and produced in London by Phoebe Keane and Hannah Barnes. It featured audio from a visualization of Earthquakes in Japan by Solarwatcher.net. The Inquiry is available as a podcast, and you can also find all our previous programs on our website. If there's a pressing question you want answered, you can demand an inquiry. Contact us through the BBC World Service Facebook page or on Twitter. We're at BBC. The Inquiry.