 Okay, well, welcome everyone to this lecture of opportunity. And to those online as well, I just quickly wanted to introduce our speaker, Dr. Patricio Winkler. He is a member of the Ocean Engineering Group at Universidad del Valparaiso in Chile. He earned his civil engineering degree, a master's in environmental technology and a PhD in civil engineering from Cornell University in 2015. He has been a research fellow at the National University of Singapore, University of Tokyo, a visiting professor at numerous Latin American universities. He has also been awarded several prestigious international scholarships, including a Fulbright. In 2023, he was appointed a visiting scholar at the David Rockefeller Center for Latin American Studies at Harvard University. So we are honored to have him here today. Thank you, Dr. Winkler. Thank you very much for the, well, it was a kind of a self invitation. Nice to visit you. And well, so it's gonna be 45 minutes of a discussion on adaptation in a changing climate. So I'm a civil engineer, as Michelle was saying, and in the last, say, 20 something years, I've been working on coastal resilience. It wasn't called like that 20 years ago. So it's gonna be an experience, pretty much focused on what we've done in Chile. Yeah, so I am from the ocean engineering department. What we do is essentially bring engineering to the ocean. That's what we do. And I wanted to thank you for you also, who has been my guest. I wanted to start with this video. I took a couple of weeks ago in New York just to give a glance on what may happen in the future in terms of sea level rise and the effects in coastal cities. So this is taken from Vanderbilt Tower. Really nice view to understand the large scale effects of what we call storm surge, which is a flood that usually affects low-lying territories in the Eastern coast of the US. And when this type of events happen, you can have lots of damage. In this particular case, here in Sandy, which impacted the area in October 29th, that's my daughter, 2012, I understand it also impacted this facility, is it? You know, yeah, I've been looking at the news and there was something about it, probably not that hard. But it was a combination of several environmental phenomena, like a really big drop in atmospheric pressure, yeah? Sustained winds blowing towards the city and the combination of both generated a storm surge of roughly like three meters or something above the high tide and that flooded Manhattan. Southern most part of Manhattan is called the battery. It affected, well, several facilities and services. And also there were lots of buildings damaged, nearly 70,000 buildings damaged because of the combination of the wind and the storm surge. So if you go to the site now, it will make it like, so this is what's gonna happen in this particular place. This is the battery, Southern Manhattan, and this video showing one site, which I'm gonna show it. It's saying what's gonna be the future flooding depth expected to buy 2050 in this particular spot, yeah? So if you look, read the note, it says that by 2050, a hundred years storm will reach that height. So what do we do with that? Is that essentially the question of all this adaptation thing? And there are several strategies to deal with this. This is a report by the IPCC, the National Intergovernmental Panel of Climate Change, where you have six different type of approaches. And the idea is to, in the remaining 40-something minutes, to go deep into this type of solution. How do we make them work? Or what are the complications they have, yeah? Now, a little bit of context in South America. So, yeah, I'm from Chile, but it used to be one of the most important ports in South America. We are affected by several hazards. Tsunami, earthquakes, sea level rise, not only sea level rise, yeah? We also, the land moves a lot down there. Waves, well, I'm gonna show you some effects. So there is the underlying idea of this line is to show that we are facing multi-hazards, and we have to deal with all of them at the same time. Yeah, that's a kind of change in paradigm in the way we design structures. Yeah, if we go a little bit, we zoom in into South America, you may see that our coast is super different to New York, yeah? It's super different. We are pretty much affected by the seismic cycle interaction between the Nazca Plate and South American Plate. And we have the second highest chain of mountains and the second deepest trench in the world next to each other, yeah? So it's an impressive place. There are also the driest deserts in the world in the North. So it's a kind of hard territory to work in. If we compare, for example, Chile, the lower part of the slide with the western coast of the US, that's kind of the distance we're talking about, yeah? 4,200 kilometers straight line, and then we also have the fjords. So if you measure, if you count the amount of cold terrain we have, it's more than 100,000 kilometers. It's impressive. Now, there is in the interaction between the ocean and the coast, we have this type of phenomenon, which is very complex, because that's a place where we actually put our facilities, yeah? And in order to understand the interaction between the ocean and the coast, we need lots of physics from the large scale to the local scale, yeah? And also the coast moves. All these are videos taken in South America. Well, actually, this one is from my hometown. So this is a snapshot, well, it's a video showing the combination of tides and waves moving the shoreline. So one of the things that we cannot take for granted is that the coastline is a fixed line. It always moves, yeah? It's one of the things that we have to take care when we are designing structures in the coast. And then we have a very highly impacted urbanized areas, like this is the port of Paraiso, it's not moving so fast, well, anyway. And so questions which may arise when we look at this system, oh, something's going on here. Ah, okay. Is, so what are gonna be the operational conditions of ports in the future in the face of changing climate? We're gonna have issues with a certain amount of data we cannot operate regarding the structures. How are they gonna behave with, for example, couple of meters or one meter more of water level because of sea level of rise and changing storminess. Also it's gonna affect this structure. So those are the type of questions we are facing in terms of port interaction, sorry, port ocean interaction. And then another issue which is something that is, it's a concept that has been raised here in Florida is that you're having sunny day flood because of sea level rise. So this type of flood, this is Chile. It's not a significant flood, but in a sunny day with high tide, you can have flooding, nuisance flooding, it's also called. And this is gonna be even more frequent and more intense in the future. So it's gonna become an issue. But then you have, sometimes have strong coastal storms like the ones we usually have in Chile. We don't have hurricanes. Our problem is this type of thing. And you can see a lighthouse on top there with the height, the rest of the light house is about 10 to 12 meters above sea level, waves are going on top of it. So it's something, so these are strong forces. And that's a ship I've been washed ashore. No, so this is a, my father used to be manager of this club. It's a club of former Navy officers. Okay. Yeah, and then what they did was to take the tower, the bridge, how do you call it? And then they put it as an office. It looked like a shipwreck. But it was washed away, washed away after this storm. So this is not climate change. This is just one example. But when you start counting, for example, the amount of the frequency at which this type of events occur in a long span, say, decades, then you can evaluate it as climate change or not. Otherwise it's just climate variability. That's a distinction you have to make. So what about risk in South America? And I'm going to show some examples and some studies we've done in order to try to assess this. And we usually use this type of framework, which I guess you're familiar to with, risk. That's a combination of hazards, exposure and vulnerability. So for example, if you wanted to assess the hazard, this type of hazards in the South American context, where you also have earthquake, how much stuff, you can start working first and understand the physics. This is, well, this is my kid. We're taller now. He's a basketball player now that we're staying here in the U.S. But when he was 1.2 meters, how many feet is that? Like a fourth, four feet, what's that for? I just want him there to compare with the projections of climate change we've done in South America, especially in central Chile. And it doesn't look that much. I mean, it would be one meter. But there's several places in the world which one meter may disappear some islands. So it's not just geometry. If you have, for example, a beach of sand, if you have one more meter, then the place where the breaker occurs, the boys break, it's also going to move. And then you're going to have dynamical effects which are nonlinear, very civil engineering worthy. So it's not just that the water is going to be one meter. Some physics is going to change. So then the large scale. Usually what we do is make these models worldwide. These are what's called general circulation models. What you have in the left is a video showing the evolution of waves within the Pacific Ocean. And then in the top right, you have average values of winds. And then you can have, for example, I'm not sure if I have light here. I cannot show it. Well, you can have, for example, what we called climate. Yeah, climate, the snapshot of the, where is the, yeah, yeah. For example, that one, this could be put in accounts, for example, the winds in the Pacific Ocean between a historical period or a baseline. That's the way we usually call computing. And then we make projections. For example, there's a projection to 2026, 2045. And then you make simply the difference between both and you can see it changes. So for example, in the last image in the top right, blue areas are going to be areas where the winds are going to be weaker than the baseline, yeah? And red areas are places, like for example, in South Chile, you're going to have much more energy generating waves and with all the cost of wisdom, it may have. So this is the type of tools we use on a large scale. And then we start going on a much smaller scale. So this is, for example, which is what we call downscaling. And where is the, oh, well, that doesn't really matter. Yeah, so these are downscaling, because what you really need to know is how are these variables, I think, one specific site. So in the center top, you have a downscaling of waves going to the Bahía de Valparaiso, which is the one I was showing you where the beach was moving. In the bottom, you have, well, measurements. So we have records, because you need to know your patience. You need to have the instruments in order to calibrate and validate those models. And in the right, we have a video. What we do is on a regular basis, we are processing that image to understand what are the interactions between the waves and the beach and if there is erosion and so on, right? So you need to have this type of tools to learn how the system works. If you, then we move, so essentially what I was showing you, some tools we used to characterize the hazard. Then if we move to exposure, exposure is essentially learning the system, which is being affected by a certain hazard. So in Chile, for example, if we were focusing in the port system, those are all the forts we have, that this is not enough at all to make an exposure analysis, you have to go into the facility and understand what's the structure of the facility, how all those great waters work, all the basins, birth sites and so on. And once you have a new characterization of the system, you can actually calculate the consequences. I'm gonna skip this one. And then if you go to vulnerability, then what you try to assess is how sensitive are, is that particular system, exposed system to one hazard, right? So it has to deal with some essential features of the system to stand, for example, flooding. And this is an example where there is a city, that's my city, which you've seen that I always use examples of my cities. It's a natural lab for us. And then what you have there is a very simple model in the left in which you are showing the hazard, light blue hazard and the future hazard. So in the bottom left panel, we have flooding in a baseline or historical period. And then in the future, because of sea level rise and changes in the waves, the waves and so on, you're gonna have a different flooding level or a different hazard level. And then, so that would be hazard. And then conceptually in this image, what you have in those houses, the houses are the exposed system. And then you can have, for example, flooding in this very simple model in house D in the bottom image and increasing flooding in houses in the future. And then you can quantify and make conclusions on this type of work. So we've done this, we use this type of a very simplified model in order to assess how cities will react to climate change, right? One of the bad things that we've seen is that in Chile, the land planning instruments are not taking at all into account what climate change is. So we're, all the cities are prone to increase the density of population in coastal areas, which is not a good news. And now if we go to ports, specifically to ports, this would be also a very conceptual and simplified model on the interaction between one particular system, and this one is a red water and one particular hazard, which is coastal storm. In the right, you have a small diagram and then we calculate, for example, the risk at which these structures will be facing in the future. And then again, you have this lighthouse of the meter tall and you see that it's something which is impressive. And that's the A-B-C-B-E birth, how do you call it in Spanish? You have this echo, echo birth that the Navy uses in Chile to birth their ships. So that's an issue. Now, from the engineering point of view, what we want to do is to reduce the risk. And then we do it by either actually acting on the hazards, exposure of vulnerability, and I'm going to show some examples on, especially those acting on exposure and vulnerability. It's very hard to reduce the hazard. You can, for example, do mitigation and reduce the gasses in the atmosphere, but that's very indirect for one particular project. But well, there are some cases shown there. I'm going to probably focus in more concrete type of solutions. So this is from the U.S. American Corp, the Corp, I think you called them SCORPs, Corp of Engineers, and they have proposed this type of solution, this pool of solutions to deal with sea level rise. You have the existing sea level, blue line, and then you have the dotted line, future sea level. And these are different sort of solutions. Some of them are nature-based solutions, like once more to the right, except for the red waters. And some of them are related more to the left with land uses and other type of instruments. So you can either have soft measures, hard measures, and you have significant variety in the kind of solutions that you can propose for a particular site. Now, we have to add something additional in Chile. We have earthquakes. So you have hurricanes, we have earthquakes. And I'm going to show you the case of San Antonio. This is the largest port in Chile. You can see a boat that ship has roughly 18,000 TEUs, containers on top of it. So it's something impressive. But the thing is that this port in 1985 was affected by a large earthquake. Yeah, the earthquake basically damaged the whole facility. Fortunately, we learned from this. And after that earthquake, what we did was to introduce seismic engineering in designing for facilities, which is something super normal nowadays, 30 years after the port, 30 years. And we also have introduced isolation. So this is seismic isolation in piers. This is a commercial pier. And what you have here is, well, some plants, I'm not going to go through the details, but there is the arrow, whatever. Well, but you can isolate. Ah, there's something going on there. Yeah. What you can do here is in this map in the right bottom, there are some red squares. And what they are is isolators, seismic isolators. So when you have an earthquake, the ground moves at a certain acceleration. And then because of the isolation, the upper part, the superstructure of the pier, doesn't move that much. And then you reduce loads. And it's a pretty good solution to stand for earthquakes. So in this type of thing, we've done pretty well. Yeah, and we are always affected by earthquakes. So we have learned quite that much. And we have imported our knowledge of seismic engineering into port engineering. But we haven't learned that much about tsunamis. Yeah, so this is an image of Talcahuano. There is a navy base next to this image. And this was a tsunami that occurred on February 28th, 27th, 2010. You can see how a tsunami can devastate the city and all those containers coming from the port and then up in the city. Yeah, I had the chance to design one of the piers in the other bay in the top. There's a construction there. And I was pretty much worried that that structure could fail. But then fortunately, the following day, the owners of the site told us that nothing had happened to the pier. And I thought, oh, our design was good. But then I went to a field and almost nothing happened in that bay. But in this neighboring bay, there was a large devastation which gives you an idea on the scale of things. How coasts react to this type of hazards. So this is the way some snapshots on what happened in that base after the tsunami. So you have floating, how do you call those facilities? Shipyards, floating shipyards? Yeah, floating dry darks. Yeah, exactly, dry darks. Dry darks, yeah. And you could see this type of devastation after the tsunami. The Navy had to invest in one particular site, 500,000 million dollars just to fix one of those pier after the tsunami. So it's a large amount of money. These are some colleagues. And what I want to value in this slide in the following one is that usually after the aftermath of these events, the Navy helps a lot when we have to, for example, do post tsunami surveys and visit places and try to understand what happened. They are always there with all their facilities and so on. And with that type of information, we can do our models. For example, in the left, there is a model of tsunami. It was a 27 February, February 27th to the tsunami propagating along the Pacific Ocean. And in the right, you have a downscaled model in the naval base I was telling you just before. Yeah, so with this type of model, you can actually calculate velocities, speeds, water depths and forces and actually evaluate what in retrospective what happened in that particular case or do your new designs to make them resistant to this type of loads. And then you can also do this type of modeling. So this is another fear in which we did it, conducted a modeling for a tsunami. So the tsunami is not well done drawn there. Tsunamis are very different, but that was kind of hard to tell the designer. But what happens to the boat is actually retrieved from the models. If you have a racing water because of the tsunami, you can, for example, break the, it's called a ship loader in this particular model because you usually do lots of models. The ships started drifting and then broke some lines and then if, well, whatever, several things. One of the, and we did this model because usually when you bring these complex models to this issue, makers, they don't necessarily need to understand it. So for example, the final production of that video is telling the story, like a time history on what could happen in that particular or if there was a tsunami attacking while you have a ship on the berth. And that gives you ideas of what you could do in the future. So for example, you could simply avoid the ship loader if you have a scenario, like an instrument measuring accelerations on top of the crane. And then if the acceleration exceeds some certain value, you can just pick it up, very simple. That's an adaptation measure. I'm gonna skip this one. Well, yeah, no, I'm gonna skip it. Yeah, but this, what I was telling that the Navy is very close, collaboration between scientists and Navy is absolutely essential for this type of cases. Yeah, well, I'm gonna say something very short about this image. This is an island and it's very hard to aid this site, especially after the aftermath. It's called Robinson Crusoe. And this is the way this particular island looked after a tsunami, after this particular tsunami which was February 27th, 2010. Yeah, this is the following day, lots of damage. All those that's floating wood, it's a bay. And so we visited the sites to try to understand what happened and found this kind of thing. So for example, houses which were middle image in the left, houses which were very close to the coast were washed away, basically by the horizontal force exerted by the fluid. Yeah, force. But in the top image, you see that the houses, the faces of the houses, which are essentially some piles, they remain almost untouched because the houses floated. So that's buoyancy. It's very different type of failure mode. So then it allows you to again, design specific measures to places or houses that can be affected by this type of loads after understanding how they work on the tsunami attack. And this is a map which is very hard to read, but it's something which is interesting. In the right side, the right map, there is a blue line and that's the flooding line for this particular tsunami. And the red boxes are houses which were washed away. Essentially everything was washed away. Yeah. Now light blue houses were those that were built after the tsunami because there was a change in the land urban planning enacted after the tsunami. So in a way, it worked. I mean, you find places which are risky and then you relocate and it works. But you can also see some blue houses in places which were not supposed to be. So good news, bad news. I don't know after this type of impacts when you don't have a very strong enactment of the land planning instruments, things don't necessarily work as you were planning. Yeah. But anyway, it can be a tool. Now coastal adaptation, this is the final part. I'm just gonna give you some examples of what kind of things that we can do. So this is a wide range, sorry, it's in Spanish. There's a wide range of ways in which we could work on the coast. If you are in a Navy base, Naval facility or whatever you need both sides and probably you're gonna need concrete or reinforced steel or the type of materials. But usually, so now the trend is try to have green coastlines and try to avoid the use of hard structures in order to protect the coast. But in places which are already urbanized, that's kind of hard. So this is a kind of catalog of the, from the most green infrastructure to the most green, blue or brown infrastructure in the right, brown because of sand, a green because of vegetation and blue because of water. And then let's see how this can work. So some examples in different places of the world. And so for example, this is a professor in the front of mine, the bottom left. This is an image of Mar del Plada. It's a very touristic site in Argentina. And this is the way in that coastal erosion was battled in the 20th century, essentially by putting hard infrastructure. Those are groins, we call them groins. What they do is generate reduction in the wave energy. So then sand becomes deposited there and you can have stable coasts. But this is very local. First, it's not the beach where you wanna be. And it's even hard, it's even dangerous because there are some, what is it, rip currents generated by the structures and so on. And a video just to give you a better idea on how does this look. So in this particular case, these groins or the touch break water, some of them are different. They provide some space where you can have a stable sand and you can also have facilities and so on. Well, in the 1960s, it could have been looked like a good solution, not anymore. So if we move in Argentina, close to this particular place, this is a place called Pina Márez. Here you see that this is a different way of approaching the way we manage the coast. Both cities are touristy. People go there and want to go to beach. But here you have a buffer zone. So the buffer zone, the urban line is away from the coast. So you have space for the sand dunes to build and you can also help the process by using for example, those fences, which reduces speed of the wind and then promotes a settlement of sand. And this is a video just showing a nearby area where you have tons of sand, healthy beach and it's a very luxurious area. So this is the kind of thing we should approach. We should use when we are dealing with a rural. Good work, rural work, coastlines which have not been affected already by urbanization. So that's a good idea. And there are several places here in the States, which I've seen that you're trying to retrieve this type of natural conditions after advancing as we did in the 19, 20 century. There are some intermediate solutions. So this is Playa del Carmen in Mexico. There's lots of sargassos over there. That's a big issue. And it drifts with the beach along hundreds of kilometers. But here they are using a very soft solution. Those sausages are in the water. They are made of geotextile and they are fed with sediments. So they give some weight and they do the same job as big waters, but you don't use rocks anymore. You use flexible structures which can promote the position of sand. And that's my hand. So when the camera changes, sorry, focuses to the beach, you see that you have a larger area with sand because you're promoting that deposition. That's a kind of intermediate solution. I wouldn't like to see all these sausages everywhere, but they do have lots of problems with post-saturation as well. There are some ideas. For example, I'm going to show you just one project we're working now in Chile that as the drone goes down, you're going to start looking at the effect algae has in this dissipating energy. So this is a very nature-based solution that I'm going to show you in the next slide. But as we assume, you're going to start looking at the forest actually moving with the waves. And you can see some waves breaking, some dissipation, foam is dissipation. It's a form of reducing the energy of the waves and also motion. So if this algae moves, it's because they are taking the energy from the waves in order to move. So we can use those two phenomena that generate vortices and break the water, break the waves and also move something in order to suck the energy from the waves and reduce the ocean. So for example, we've been using, we're currently working this project which is fascinating at least to me. It's a small-scale project. We're building an algae forest in the right bottom image. It's a one hectare. It's made of roughly 150,000 small seeds of plants. So imagine people planting this. So it gives lots of work to local people. And what we're doing is essentially using all those tools in the right, no worry about modeling, monitoring and so on, to check if this type of device could work in reducing the wave energy. And this is just an example of adaptation. It's a very soft and nature-based solution. But then we can go to hard solutions. And this is a schematics of Sendai. Sendai is a city in Japan which was devastated by the March 11th, 2011 tsunami. I was there, I work in the University of Tokyo. So I know pretty much about this case. And this is a small version of actually what was done on the site. And it's for kids to play, right? So this is essentially what they called a multiple layer defense. So you have coming from the right to the left, you have the sea. First you have a beach, sandy beach. You have groins that submerge groins to keep that sand there. Then the first green blocks, those are essentially what they call tsunami forests, that they suck the energy from the tsunami. And then you have some sort of secondary green blocks and those are elevated lands to make, to provide evacuation zones for people that don't have the time to, you know, travel to save zones in the city. This is a very large area. So roughly, this is conceptual, but it's like 4,000, a four kilometers, what is it, terrace, coastal terrace, very long. So you don't have time to do one four kilometers and each highlands. And then you have some roads which are elevated, the green ones. Yeah, so they are designed to stand scoured, which is what the water interact with the structure. It can actually break it. You also have this orange buildings which are evacuation buildings in places where there's no space to go up. Yeah, so this type of solution was made insundide after the city was essentially devastated. Well, it's not just one city, several small towns in the area. Another thing the Japanese have been doing, so for example, this is Kobe. This is a port which was also destroyed in 1995 because of an earthquake. Yeah, and it's affected by typhoons and tsunamis. So what they did was to build these walls along the entire city. Yeah, and the walls have this kind of sliding metal elements. And once there's a storm surge warning, they close or if there is a tsunami, they also act like that. So you have a triggering mechanism that makes them close and if the tsunami is not that big, yeah, it will eventually reduce or actually mitigate, absolutely mitigate the flood in the city. But this is expensive. So it depends on the location, it's pretty much dependent on the local resources, knowledge and all that stuff. And this is an example of Boston. Since I'm working now in Boston, this is a small scale solution, which I think it's pretty interesting. And it's a former era which was flooded and it was industrial. So what they did was to reconvert this into a prominent and this kind of place where people are sitting is a seawall, but it's also used as an urban solution. So this is assumed to a type of solution they used here. And this is going on in Boston in several places. So all the green area is a new park. The red line was the seawall and this is a cross section of how they did it. So this is not that hard. So it's a good solution. Which I guess could be implemented in developed countries. This type of solution could also be implemented in countries like Chile, but the difference between you and us is that we can have an earthquake and the coast can subside two meters. So you can make all your numbers and then earthquake done. So it's interesting. And I think I'm just about to finish. This is another example of hard infrastructure which is very well designed. This is Singapore and this is a storm surge barrier. Singapore has no sources of portable water or drinking purposes. So what they did essentially, because they don't have rivers, it's a very small island. What they did was to, they have an estuary and they put this structure and the structure has three functions. First, you can keep because you have televerts here. You have blocks or whatever you call them. You can regulate the level of the water inside. And if you level the water and you have lots of touristic activity like marinas, it's very simple to design because water is something, it's a value known. Whereas if you design something here, you have the tide up and down, you have to operate in different levels. So it's good to have always the same flooding level. It also protects the city from storm surge which happens in the other side of the structure and also stores water which will be later used or supplied to the city. It's very interesting. It is like being in the future. This is a Singapore. And here you see that that's an estuary. Yeah, and here you have the storm surge barrier. And yeah, well, Singapore can do it. The per capita income is really high compared to developing countries like Chile and so on. So you have this pool of solutions. It will depend on what are your resources and so on. And I think I'm done. Yeah, what are you gonna do in your own country? I put this one because there was a meeting in Brown University in May, wasn't it? Yeah, and we were discussing about the time in action plan program that the Navy here in the US was drafting. Pretty interesting, so, but well, I don't know. That was it. Do you have your residence? No. I have a novice question which is I'm familiar with hurricanes and tidal rights, but happily not having experienced a type of, I don't know, it's not economic. Are the waves different because of where the earthquake do they come in a shore in a different way? Again, I'm not a scientist, so I don't know. They're different. Okay, so the storm surge, the storm surge is slow. It takes hours to build up. And then you say, how the storm surge where it's here, especially in these estuaries is that you have wind blowing to the coast and the wind transfer energy to the water. Yeah, and then the water starts moving. And if you put a structure or a coast, then it will start piling up because of the effect of the wind. But also you have, usually you have low pressure, atmospheric pressure, that's usually bad weather. With low atmospheric pressure, your pressure with less pressure, the water, so the water goes up. So you have those two effects. And when you have fjords like this, yeah, and you have the wind blowing this direction, pressure, low pressure, the estuary funnels, the water inside, and you have an increase. What happened in New York? So if you have Manhattan, you have the inner bay, outer bay, and the Atlantic Ocean. And in Atlantic Ocean, the effect is much smaller than the one in Manhattan because you have this funneling effect. So you have, well, atmosphere and also local conditions, which, and that's low, it takes hours to build. But a tsunami, it's like this. And it can reach in the case of Chile in 20 minutes. So the wave can come and it's impressive. So I've seen, I've seen in the field the impacts and you can have a flux of, say, 10 meters per second, which is something that, sorry for this, 10 meters per second, yeah? It's something like that speed, yeah, that speed. But imagine a flow of that speed and say five, six meters depth attacking a city. That's impressive. It's impressive. And then you have coastal stop. This is it. You may, let's say, classify the type of impacts in terms of the intensity and the duration. So tsunamis are super short, super intense. And is there a direction to them or do they just come in the shore the same way? Well, it's very complex. The flow is super complex. Usually the first wave is kind of clean, but then you have secondary waves and then they start interacting and it's very messy. I mean, when you see it in the field, you can see, for example, a tree like broken in this direction and the neighboring tree broken in the other direction. You have the inflow, outflow, yeah. And these ideas, tsunamis are short, but very intense. Then you have storm search, which are a bit longer, but less intense. And then you have things like this sunny day flat, which is very slow and it's increasing and it's very frequent, but with low energy. So it depends on the phenomenon you're analyzing. I went up and down the Eastern coast of Japan on the five-year anniversary of 2011 and I saw how much they had built up. One lesson is there's no way you could do that in the United States. Everyone would say, oh, you're ruining my view. But you had that great picture which is exactly what they're doing. What we would call defense in depth. They kind of have different things that are less vulnerable, closer to the water line and then another firm or a dyke and then back in. Have you seen that anywhere else in the world? Well, Dutch do something similar, but they don't have the multilayer type of solution. They were affected by this Vlad in 1950 something which flooded the southern part of Poland. What they do is essentially have dykes and then dykes of dance, advance, advance. You have a series of dykes and then they drain the land and they have agricultural lands, but I haven't seen such thing anywhere. And that solution is pretty much focusing on dykes. You have these planes and then you have lots of space also to put the tsunami forest. I was in Japan, it's called Forestry and Forestry Project Research Institute and then they were designing, testing a forest type of solutions. They need lots of space and you need, for example, red pines which will fix the soil, but then you need intermediate bushes and I don't know how you call them like very small bushes because then you start sucking the energy from the flow at different levels and this matrix is the one that worked, but you need space. And in Sendai you have space. In some other places, if you go to Sendai to the north then you have this very rocky coast and then they put, you know, dykes, huge dykes. And it's impressive. And the way they managed the coast is impressive. And they have evolved in the years because they've had several tsunamis. So, and if you see the story of the height of the crest of dykes, it has been growing ever since whenever you have a tsunami and they are flooded and you can see them in places. But no, it's a tragedy. And that's part of the story they tell because sometimes they leave, they explain why the old dyke didn't work. The old seawall that they built what didn't withstand that 2011 tsunami. Yeah, yeah. Therefore they have to build it even higher. Right, right. What happened, the way the dykes failed in Japan, not generally, but well kind of generally is that if you have a dyke and then the water starts spiling up and then you reach the crest, then you have this kind of spillway and the spillway generates vortices here. And then that's scour. So the breakwaters started getting scour. Do you understand scour? Yeah, they're losing soil. And then, look. Yeah, it kind of eroded underneath, right? Right, right. And now what they do is they, so I've seen some, is that they are doing in the inland part, they are reducing the slope. So the flow and all these effects are not that hard. And they also put rocks because rocks are really good at reducing scour. So they change the design and they also put it higher. Instead of that, they build this 30-something kilometer long wall. And that's important to do in elsewhere. It's like a landmark. Right, right, right. Thank you. With all these things, I mean, sea level rises, but most of our problems, I think in the U.S., is problems. Basically, I just lost the word, but just consolidation of the soil. So we're subsiding. Right. The soil is dropping. So like New York has dropped so many feet over the years, right? So for us, I think, do you probably don't have the subsidence except for... Not in our case. For example, in Jakarta and Indonesia, they had that huge problems that the land is sinking because you're putting burden on the top of the soil. So for example, in Chile, when we built, when we built that building, the design kind of rule of thumb is that you have the soil, and then if you're gonna put a 20-meter building, you're gonna extract similar amount of weight from the soil, where you're gonna build the partings, yeah? In a way, you kind of balance the overweight, but in the case of Manhattan, you're putting all that concrete, so it goes down. And then you have subsidence because of the overload, and you have sea level rise. So both of them are. And then you can also have subsidence because of pumping water from the wells. That's my thing. So in the U.S., some of these large, heavy coastal offenses will actually make it worse because you will compact the soil. You will make it so heavy unless you can get really deep foundations. Well, it depends on how large are they? Because one thing is, so if you build something on soil, you have a, it's called a bulb, pressure bulb that is affected. In the case of Manhattan, it's not a bulb, it's a conjunction of several structures which both together make this kind of large scales of silence. But if you have a wall and it goes down because of its own pressure, you could actually increase the crest height. That would be like a, we call it adaptation pathway. You say, you're gonna use this structure, this solution, and then probably when you have a triggering event, lots of over topping, then you increase the height, but you don't do it immediately. You wait until there's a triggering action. Because like the higher the wall gets, the heavier it gets in the figure of your bulb. Exactly. So it's almost like, it's a permanent work for civil engineers. Right, yeah. So it's like the ice cream. And you know, I mean, it's called the GSD, Graduate School of Design at Harvard now, and they are architects people working and they treat engineers as demons. So the U.S. corporate engineers, they are the worst people in the world because they are building the structures and well, I'm fantasizing a little bit on what they're saying. But there is this perception that the 20th century type of infrastructure built by the U.S. corpse, whatever it is, is mad. It's contaminating the problem at times. Is it what? It's making the problem worse. Yeah, kind of. But another thing is that there are several urbanized areas in which you cannot go back. You're not going to use what's called nature-based solutions in Manhattan. You're not going to do that. You already built and gained all those lands and so you need to find harder solutions and probably you will still need engineering and hard structures in order to cope with the sea level rising that comes up. It's very local. This was not part of your presentation, but I'm curious. So we can see like China building these man-made islands, which is kind of an engineering problem in itself. Any idea how the construction of those, how sea level rise is going to impact them? But do we have any sense of how, because of the engineering behind it? No, I don't know the project itself. I know they are doing that kind of stuff, but I don't know exactly. So when you come to engineering, you have to start measuring things. You need to measure how high they're going to be, how they're going to match with coastal erosion. So it's like when you go to a doctor and the doctor tells you, like, I think that this is going to happen, but I need tons of exams to do that. And I know this. I don't know that. Thank you. Wonderful. Thank you. Thank you very much. A pleasure.