On Earth, the power of the sea is the most elusive of all natural forces. The undercurrents under the sea can sweep across the entire ocean and swallow up entire cities, leaving behind tens of thousands of corpses. Looking back at history, tsunamis have caused many shocking disasters. They are domineering in almost all oceans. They are always invincible and never merciful. They are wave killers and attack humans again and again. The wave itself is both deadly and mysterious. It can reach speeds of 700 kilometers per hour, and an attack will cause the entire earth to shake. We saw from the movie "The Day After Tomorrow" that the huge waves almost submerged the Statue of Liberty, and the overwhelming seawater poured into the bustling streets of New York. This ferocious monster is the most ferocious killer on earth - the tsunami. However, while we were still intoxicated by the visual stimulation brought to us by high technology, real tsunamis struck many countries along the Indian Ocean, killing more than 160,000 people. What force makes the tsunami so raging?

On the morning of Sunday, December 26, 2004, the crustal movement under the deep sea of ??the Indian Ocean southwest of Sumatra, Indonesia, suddenly occurred, forming the third largest earthquake and tsunami in the history of the earth. Within seconds of this huge earthquake, a large crater appeared at the bottom of the ocean that was hundreds of kilometers wide, thousands of kilometers long, and several meters deep. The resulting violent seawater shock was equivalent to the energy of one million atomic bombs dropped on Hiroshima, Japan. In an instant, the people and everything on the shore disappeared into the huge waves. This tsunami was caused by an undersea earthquake. The underground fault was a reverse fault with a magnitude of 9.

The Indian Ocean tsunami caused by a strong earthquake started to cause a human tragedy within a few minutes. An hour or two later, it spread to 12 countries along the Indian Ocean coast, swallowing up 160,000 innocent people. creatures, causing an unprecedented disaster. While we feel sorry for the victims, we also bless the survivors of the disaster. Regardless of whether they are poor or rich, celebrities or ordinary people, when they face this huge wave, their life and death encounters give us the enlightenment that first, people from different countries face the same nature at the same time and in the same place. Disaster; second, the fragility and tenacity of life.

What should we do when we encounter a tsunami:

First, earthquakes are the most obvious precursor to tsunamis. If you feel strong vibrations, do not go near the seaside or the mouth of a river. If you hear reports of a nearby earthquake, be prepared for tsunamis and pay attention to television and radio news. Remember that tsunamis can sometimes reach thousands of kilometers away from the earthquake's source within hours of an earthquake.

Second, ships at sea should avoid returning to the harbor after hearing the tsunami warning. The drop and turbulence caused by the tsunami in the harbor are very dangerous. If there is enough time, the boat owner should move the boat to open sea before the tsunami arrives. If there is no time to leave the harbor, everyone must evacuate the ships anchored in the harbor.

Third, the sea water often rises or falls significantly when a tsunami makes landfall. If you see the sea surface retreating abnormally fast, you should immediately evacuate to higher ground inland.

The earth is the home given to us by the universe, but it sometimes changes its face; the sea is the source of life given to us by the earth, but sometimes it gets angry. Look back at yesterday's disaster and discover the true feelings of the world; remember the lessons of blood and cherish today's peace. Let us join hands to live in harmony with the earth and the sea.

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You may also know that an American blockbuster "The Day After Tomorrow" was broadcast across the country last year. I don't know if you have seen it, but the plot of this movie is like this , it talks about three kinds of disasters, one is a tornado, one is a tsunami, and the other is a low temperature and cold. The reason for these disasters is the greenhouse effect, because humans use too much energy, and cars emit too much smoke. Various influences The temperature of the entire world has increased. Originally, the earth has achieved equilibrium after 4.6 billion years. Due to the greenhouse effect, climate warming has caused the polar ice caps to melt, causing sea levels to rise, so that the climate has extremely deteriorated, causing Disasters are happening all over the world one after another. In the film, it is shown that a tornado hits Los Angeles, a tsunami hits New York, and low temperatures threaten the vast areas of North America. People's lives there are plunged into unprecedented disasters.

This clip is dedicated to introducing the tsunami. You can see the scene. In a place with many high-rise buildings in New York, people are living leisurely, working or going to school. Suddenly, strong winds blow, and The waves came all over and rushed into the city. People ran to tell each other and helped each other. The waves behind them chased them. People ran forward, and some people couldn't keep up and fell down. There is a relatively large library that can be used as a refuge. Some old people, with the support of their families, and some company employees with the help of others, ran to this library together. When these people crowded into the library At that moment, the waves came from behind. A man from behind just went in and closed the door. The waves surged onto the door and hit him in the face. This was a scene at that time.

The movie you just watched is not reality. It is an irresistible horror scene created with high technology. The director made the audience tremble with fear, even though it did not say it was today or tomorrow, but deliberately placed it the day after tomorrow. , the title is "The Day After Tomorrow", but after watching it, it still achieved this result. People are worried about the future. Speaking of "The Day After Tomorrow", there is a translation of the title, the original text is The

day after

tomorrow, you see, the translation in Hong Kong, Macao and Taiwan is "Tomorrow After". The future is not just one or two days, but a long time. The translation in mainland China is "The Day After Tomorrow", which refers specifically to this day. In addition, other Chinese regions , translated as "Doomsday Catastrophe", the day after tomorrow and the day after tomorrow, isn't that the future? It's a disaster, it's a catastrophe. Why did I put the three translations at this point? This shows that our understanding of the film is still not deep. Disasters are not a matter of one or two days, but a long-term problem. Therefore, we have a long-term understanding of disasters on the earth. We cannot take it lightly and must always pay attention to it. After seeing this, we can say that the day after tomorrow that we did not want to happen has finally arrived.

This Indian Ocean tsunami was caused by an undersea earthquake. Now we always talk about tsunamis and tsunamis. Don’t forget who caused them. In the future, I will say that it is not only earthquakes that cause tsunamis, but also huge tsunamis. Mainly earthquakes, and the energy provided by most of the disasters caused by tsunamis is submarine earthquakes. Let’s talk about a magnitude 9 submarine earthquake that occurred near Sumatra Island, Indonesia. It was the first earthquake since records began. Three giant earthquakes with magnitudes 9 and above, huge earthquakes. Since there are three earthquakes with the same magnitude, we arrange them by size. As you can see, it is fourth. The Kamchatka earthquake in 1952 was a magnitude 9.2 in the northern part of the Pacific Rim. , Alaska's 9.2 in 1957, Chile's 9.5 in 1960, this is the leader, Alaska's 9.2 in 1964. By the way, the earthquake magnitude we usually see in newspapers is usually called the Richter scale, which is called the Richter scale. It is a magnitude scale, just like we say temperature in degrees Celsius, Celsius, Fahrenheit. Similarly, it is a magnitude scale. When we measure temperature, we usually use a mercury thermometer, but we can also use a thermocouple. It is a technical system. No matter what it is used, its scale is fixed. What is zero degrees Celsius? If water freezes, it will definitely die. So there is also a regulation on the Richter scale. What is a zero-magnitude earthquake? It was the Americans who first used a fixed instrument called the Wood Anderson seismograph in Southern California. They used this instrument to observe an amplitude of one millimeter at a distance of one hundred kilometers. Then its corresponding magnitude was called zero degrees Celsius. It was determined like this Yes, so from now on, if you look at the Richter scale mentioned above, you just need to know it. Therefore, the magnitude 9 earthquake in Indonesia ranked third in a century, but the death toll from this earthquake and tsunami ranked first. This is not all the data, so I will just pick some of them. Lisbon, Portugal, had 30,000 to 70,000 people in 1755, Sanriku, Japan, had 27,000 people in 1896, and Messina in 1908. This is not Mexico, but another place name. 85,000 people, 900 people in Chile in 1960, and 150 people in Alaska in 1964. You would think that the total number of people is declining, but suddenly in 2004, Indonesia only reached the Indian Ocean. An earthquake and tsunami killed more than 160,000 people, and 16 What does tens of thousands of people mean? The number of deaths is equivalent to the total number of tsunami deaths along the Pacific coast in more than 1,300 years. According to statistics from 1,700 years ago, there have been 260 destructive earthquakes and tsunamis around the world. According to the records of tsunamis along the Pacific coast in more than 1,300 years, , how many people died? 140,000 to 200,000 people died in the tsunami disaster. Look, our 160,000 people are comparable to it. This is an important reason why this disaster has attracted global attention. Too many people died

Let’s take a look at the formation of earthquakes. We know that any earthquake must be related to faults. My old master, Professor Chengyi, has passed away. He once said a famous saying during his lifetime. He said, "There must be earthquakes." "Fault", you go look for it, there must be a fault. On the other hand, in the second sentence he said, "If there is a fault, there may not be an earthquake." Everyone understands that there must be an earthquake because there must be a fault. Now that you have discovered a fault, it Will there be another earthquake later? It depends on whether the fault is still active. Let us use an image to describe whether it is a dead fault or an active fault. Now many big cities in Beijing and Tianjin are conducting an important part of earthquake work, called the survey of active faults. Earthquake safety assessment, look at where there are faults under our feet. If there are, don’t build this part of your building, and don’t build this part of your stadium, so we also participated in the construction of the Olympic venues this time, called Live Detection of faults and evaluation of earthquake safety.

So what type of earthquake fault is this time? In this way, we must talk about three types. On the left and right sides of the fault, there is a crack in the middle. If this fault is not like cutting tofu up and down, it is likely to be tilted and cut diagonally. Then I am on the top, this is The lower part is called the hanging wall and the lower wall. If I go through this, it will slide down along with my own gravity, which is called a normal fault. However, if an external force is used to push me upward, it is called a normal fault. Reverse fault, then the nature of this earthquake is a fault, a reverse fault. Please pay special attention to it. What was the metaphor of my hand just now? My analogy is that I am not moving like this. You know, this is called a flat inference layer, a translational fault. If there is such a movement, the earthquake will not cause a tsunami, because it will not lift the water above, nor will it pull it down. Instead, I tilted it a little bit, and there was a tilt-slip component. The tilt-slip component pushed up, and the billions of tons of water above pushed it up. The power of this earthquake was very, very powerful. The energy of more than 1,000 kilometers of faults suddenly hit this place. The child is released, so we talk about the north-west thrust nature, which has practical value and guiding significance. By the way, here I will give you a concept, what is the energy of plate movement? We all know that the global plates are moving and squeezing each other. This energy is very large. The squeezing and bumping will cause an earthquake, so the energy of the earthquake is the energy of the movement of the plates. A part, a very small part, then the current earthquake causes tsunamis and wave fluctuations, so it is part of the seismic energy. Then, who provides the energy for plate movement? It is the mantle underneath the earth. There is convection in it. The mantle Underneath is the core of the earth, the hot core of the earth, just like the pancakes we bake at home. No one would have thought that there is coal underneath. The center of the entire earth is boiling hot, thousands of degrees. With high temperatures and millions of atmospheric pressures, it is baking our earth and constantly releasing energy outwards. However, we have not studied it enough in the past. In 1997, Chinese scientist Song Xiaodong discovered that the earth's core is rotating. I didn’t know this in the past, and thought they were all closely connected to each other, just like the egg skin is connected to the egg white, and the inside is connected to the egg yolk. No, now the egg yolk is rotating inside, and it’s very fast. This is a Chinese thing A major contribution was made by a young man who studied there. In other words, the energy of the entire earth affects people from the bottom to the outside, layer by layer, providing people with living conditions, and at the same time, it also brings disasters.

To put it simply, three indispensable conditions must be met for the formation of earthquake and tsunami disasters. The first is that the deep sea water is hundreds of kilometers deep, the second is that a major earthquake has a magnitude of 7.5 or above, and the third is that It is the favorable geographical conditions of the coast and the seabed, that is, the terrain. When our tsunami reaches the coastline and lands, if it enters a bay or port, why is it dangerous in this place? Because there is also so much water, and now it is not an open area, but a very narrow channel. The water has to go from here, and it can't pass. You squeeze me, I squeeze you, and it squeezes up. It squeezes up a very high column of water. It's easy to understand. Then we say that not all submarine earthquakes will cause tsunamis. Someone has made statistics and found that among 15,000 submarine earthquakes, only 100 caused tsunamis, so it is less than one percent. In addition, we can say with certainty , earthquakes of magnitude 6 and below are basically unlikely to cause tsunamis. If your home is in Tianjin, Shanghai, Zhejiang, or a coastal area, if an earthquake of magnitude 6 or magnitude 5 occurs there, don’t worry, don’t follow them. If a tsunami is connected, it won't happen even if you want it to happen. It doesn't have that much energy. Let me tell you, this earthquake not only caused a tsunami, but also caused the entire earth to shake. Just like a big fat man, after running, he stopped and "hooked" and gasped. Why? ? Because the entire earth is an elastic body, it cannot help but vibrate and sway when it is stimulated by a big earthquake. Everyone knows that if we ring the bell in the Great Bell Temple, the bell will ring ten miles away. Why? Why does it keep making noise? Because when it hits the earth, it stimulates strong energy. There is a dynamic demonstration of a tsunami, which is provided by the Environmental Center of the National Oceanic Administration. What is it? It means that the wave spreads outward layer by layer. When the water wave starts, you see the middle of the water falling, and the drop spreads outward.

Then let’s talk about the causes of tsunamis. Just now we talked about submarine earthquakes, which is one of the causes. In addition, there are volcanic eruptions, which can also cause tsunamis, especially submarine volcanoes; the other is subsea landslides. The seafloor is the same as the land we see. There are also mountains and some plateaus below. They are plateaus under the sea. Various reasons may cause landslides, causing a shock in the sea water; underwater explosions and nuclear explosions are no longer carried out. In the past few years, there were first airborne nuclear explosions, and then underground ocean nuclear explosions, but now they are all underground, because It pollutes the environment greatly. Such an explosion under the sea, or a man-made explosion, will also trigger a tsunami. Why do some of us want to catch fish instead of taking packs of explosives and "exploding fish" in the river? The waves that everyone sees will also start rolling. ; The other is the fall of celestial bodies. If a comet or a meteorite hits the sea, as it itself is depleting and burning, it carries its remaining energy and rushes into the sea, causing a tsunami. We mentioned these five types above, but the most important one is earthquake and tsunami. Tsunamis caused by earthquakes account for the vast majority.

Now let’s turn to the second question, tsunami. Earthquakes only give energy, while tsunamis cause destruction. Here we give you a concept of the scale of the tsunami source. The size of the tsunami caused by the earthquake, We say that the tsunami source is not a point, but the final impact is a surface, but a small area. This area can be calculated using a formula, which is a simple logarithmic relationship. Let us give two numbers. An earthquake of magnitude 8.5 is equivalent to Less than 600 kilometers, what, the tsunami source is the scale that causes the tsunami. The other one is magnitude 9.0, which corresponds to the scale of 1,000 kilometers. Speaking of this, everyone has a concept to pay attention to. An earthquake occurs at one point, the rupture point, but the energy provided is very long. For example, if I hold a board in my hand, I will break it now - break, quack There was a sound, and the rupture was at one point, but the whole force I exerted was on the entire board, so the earthquake now happened at that point with the energy accumulated in a large area of ??more than a thousand kilometers.

After an earthquake, what propagates in the solid earth and in the rocks under your feet is called seismic wave, also called elastic wave. So the tsunami propagates in the ocean. What kind of wave is it? They are gravity waves, which are caused by the weight of objects oscillating up and down. Unlike seismic waves, which are squeezed and twisted by the deformation inside, these are two types of waves. Because submarine earthquakes are violent dislocations of submarine faults, they will cause violent fluctuations in the water body. This is Tsunami, a tsunami is the oscillation of water, a strong oscillation, with a wavelength ranging from several kilometers to dozens of kilometers, and a wave speed of several hundred kilometers per hour. There is also a formula, because its speed is proportional to the square root of the water depth, because as you can see, this wave The wavelength is very long, just like when we watch the waves at the beach, everyone sees the ups and downs as very long. If the wavelength reaches hundreds of kilometers, then when you sit on a moving boat, you will not feel anything at all. It's not like this ship is shaking, because the scale is too different, and because the amount of wave fluctuation is very small, on a calm sea, the ratio of wave height to wavelength is very small, the bumps of the ship's hull are small, and the tsunami is almost not felt, but it is not It means it does not exist, and generally it will not cause a disaster. If there is a tsunami and you are at sea, you must not run to the shore. It will be too late. If you do not handle it well, it may also come with the tsunami and face the enemy. What to do? Go into the deep sea, because in the vast ocean, you can't notice the tiny vibrations.

Now let’s see what new experiences this earthquake and tsunami can give us. Well, this disaster brought together the most developed and the most backward areas in the world, the richest and poorest people in the world, and even very powerful people like Cole, all at the same time and place. The same kind of catastrophe is a phenomenon that has never happened before. Some people say that our global village is getting smaller and smaller. Why do we see old friends who have not seen each other for many years? Everyone often says, "The earth is too small." This is not the case now. It is said that you saw an old friend, but it was a disaster. People from such a far away northern Europe, and Indians, the hottest people in this place, encountered disaster together. How could this have happened in the past?

Second, the lives of people in our global village have never been so fragile, and have never been so tenacious. These are two contradictory aspects. There are some people who survive, so they will try their best to survive. Let me give you some examples. We can see that some people miraculously survived being swallowed by huge waves. We have to ask whether this is an exception or a universality. From a personal perspective, it is an exception. From a human perspective, it is an exception. The desire to live and cherish life is universal, but unfortunately not all people have this opportunity.

We want to get a kind of enlightenment. To truly avoid disasters, we must have our own knowledge, but also the support of the broader society, and the government that supports this society. This constitutes different levels. Only with such a power can it be possible to avoid and reduce the losses of disasters:

The first story we tell is "Mother and Son in the Tsunami". You may have seen it in the newspaper. The mother is a policeman. , she has three children, you see three arrows drawn, what, these are her three children, and among them is her younger brother, at the seaside. This is her, the protagonist of the story. Everyone has seen the white one. The white color is the waves, the tsunami. When it comes, she runs towards the waves, running away for the danger, but actually running towards her child. A family of five people came here to play. She said, "I saw a white wall of water approaching from the horizon to the beach. The wall of water was getting bigger and bigger. The tourists started screaming, get off the beach quickly, leave quickly." Beach, I also shouted to these people playing in the sea, but they couldn't hear it because the noise was too loud and the waves were too loud. They didn't know that the huge waves behind them were coming toward them. "At this time, she heard people. He warned her to leave the beach for fear that something would happen to her, but in order to save her child, the mother said, "I can only ignore it, because nothing can stop me. I just want to be close to my children and protect them." However, When she was 20 meters away from her children, a wave came over and flipped her three children and her brother into the huge wave. Soon after, she was also swallowed up by the overwhelming waves, but fortunately, or perhaps a spirit from heaven was moved, the mother was lifted up to a high ground by the flood, and was lifted up and thrown to the high ground.

Ten minutes later, she went to look for her relatives and her child, and suddenly found her whole family on a high ground farther away from the flood. She saw her child, her husband, and her brother together. , hugging each other tightly, full of fear and confusion.

This is "a small popular science solves a big problem". A child saved a hundred adults. This is a little girl from the UK. She and her family were on vacation in Phuket while playing. , she said, "I saw bubbling and bubbling on the sea, and the tide suddenly receded, and the bubbling receded. At this time, she said, I immediately realized that a tsunami might be coming, so I quickly told her Mom, there are so many articles just with the words "I suddenly realized". Later, her mother notified the management of the beach and hotel, and evacuated more than a hundred people, and for a few minutes there was a huge wave. When the earthquake and tsunami hit, there was no one on the beach. It is said that this beach is one of the few beaches in Phuket where no one died in the earthquake and tsunami. So why, people are very concerned about this. Well, this little girl said that the reason why she understood tsunamis so well was because before arriving in Thailand, her class had just held a special lecture on tsunamis. By coincidence, the child is a thoughtful person. When all the abnormalities appeared on the sea, The situation was consistent with the introduction in the lecture. Therefore, the smart child had a premonition of the earthquake at the first time. She made a personal warning and saved a hundred people. If there were more such children, many lives would be saved. ?, so the science is small, but it can do big things.

Elephants save tourists. Everyone likes to ride on elephants when they go there. The elephants are gentle and squat down for you to sit down. This tsunami happened. In the future, it was discovered that many animals may have some premonitions about natural disasters that exceed those of humans. In a tourist resort in the north of Phuket Island, Thailand, tourists riding an elephant suddenly discovered that the elephant was going crazy and took him with him. He followed him and ran up the mountain. The man hugged the elephant tightly. He didn't know what was going on. He was panicked. The man driving the elephant didn't know what was going on. He chased it. When he reached the top of the mountain, the elephant slowly stopped. When I came down, I looked back and saw that the big wave was coming, and I followed my footsteps. The elephant's premonition is completely sensitive to vibrations. I tell everyone that I am engaged in earthquakes, ground shaking, and seismic equipment. This person At home, you can know by the sound of your footsteps that your child is your wife. You can also feel that the elephant and the elephant herd are tens or hundreds of kilometers apart. They convey information and talk about love. Just rely on those thighs, kicking, pushing, kicking, to produce underground fluctuations. There is a special article here to introduce this aspect. Different vibrations, different frequencies, different amplitudes and different rhythms all express different meanings: I am encountering difficulties. Everyone, please help me. The elephant herd is here. I need your help if I need anything. I especially miss my friends. The elephants take different kicking actions, so I think the instincts of these animals are well exerted, so this example There is still a scientific basis.

Here is some knowledge. What should you do if you encounter a tsunami?

First, if you feel shaken, you must consider the possibility of a tsunami. , of course you live by the sea, that’s it in a nutshell

Second, if you hear a tsunami warning, what should you avoid? Avoid returning to the harbor, because it is easy to cause high waves in the harbor. If you are on a boat, you should drive the boat to open water, drive out of the harbor, and evacuate the boats in the harbor. In short, this is a dangerous area, a dangerous area.

Third, if you see the sea water rising or falling significantly, and the ebbing or rising tide speed is very high, what should you do? There is only one way, thirty-six strategies, escape is the best strategy , run to higher places, people walk to higher places, and water flows to lower places.

What I just talked about was a person, as an individual. There is also a technical system that emphasizes a tsunami technical early warning system. Tsunami technical early warning includes three:

The first is earthquake monitoring, which also refers to earthquakes and tsunamis;

The second one is followed by a dynamic tracking of the tsunami. There is a calculation of where the wave went, how high it got there, and how long it took;

The third one, I will tell you after the calculation is done. After talking about arriving at that place in a few hours, the officials and experts at that place must have a way to inform everyone. If you don’t inform everyone, the information you will get is zero, so the monitoring system, tracking system and communication system are three necessary aspects. .

Currently, a tsunami early warning system has been established in the Pacific. Japan has a very complete national tsunami early warning system. Let’s talk about building it. Don’t you know that it is very expensive to build this? You need to order a seismometer. An earthquake is not one station, but several stations. So building a seismic station and a network requires hundreds of thousands or millions of investments at a time. This is not difficult for China. Why? Because it already exists. China already has a seismic network. Now there are still some problems to be solved regarding the tsunami schedule. You reported this location and it spread. How did you know that you came to me? You can't say that I saw it. , the waves are monstrous, then I don’t want you. There must be a detector under the seabed. What to detect is the underground pressure of the seafloor, including its water pressure, including underground stress. Such an instrument is very expensive, and its probe needs to be pierced. On the rocks, its information floats on the water. What does it mean? Their ears are attached to the ground and their mouths are exposed on the water. What are they doing? Tell this message to our communication system and tell us. The TV stations tell our telecommunications bureau, and then they are gathered into a center to analyze the data and make judgments. For example, if you forget it and calculate it, when will the tsunami arrive? Is that the case? I have to test it and judge its possible size, so the coastline monitoring system and the tsunami tracking calculations are mutually reinforcing and calibrating. According to them, it would cost 200,000 U.S. dollars to build such a device on the seashore and under the sea. This is not a small number, because the seabed is deep and the conditions there are very, very harsh, because cables are needed to communicate with the outside world, and a lot of new ones are needed. Technology is easy to buy, but more difficult to maintain. According to them, maintenance fees cost millions or tens of millions every year. People say it doesn’t matter how much money you have, as long as it can save lives. I have money. The problem is this. Today’s The success rate of tsunami forecasting is not very high. According to some statistics, during a certain period of time, one statistic showed that 15 times out of 30 times, the forecast was inaccurate, and only 15 times was accurate. People say it is so low. I am very envious. Our earthquake prediction is not yet at this level, 120%, 230%, so with such a large investment, we still don’t have enough grasp of this law, so it becomes a social issue at this time, and the investment issues, and issues of public understanding. So, this monitoring system for the Indian Ocean tsunami, I listened to the radio this morning, and I also read it online. I have decided to build it and invest 30 million US dollars. An investment of 30 million is a huge investment. I need everyone's help. , Fortunately, there is a relatively wealthy country in Australia, and everyone is helping to help these countries in difficulty. But we must be aware of this issue. We cannot rely solely on technology. From a purely technical point of view, we will suffer great losses. The Americans considered this situation and later sent people. Not all of them were unmanned, or Someone is sent to conduct monitoring and proofreading, and the instrument is called "tsunami police". The quotation mark means that there are both instruments and people to conduct interactive prediction and monitoring of tsunami.

So, how far is our country from tsunamis? Regarding this question, how far is it in front of us? Let me tell you the conclusion first. This may be a family opinion. Our country is not only less prone to earthquakes and tsunamis in coastal areas, but also in the far seas. Earthquakes and tsunamis that occur will not pose a threat to our country's coast. I'm going too far in saying this, it's just a matter of family. Because, why I say this, one basis is based on the geological structure. Except for the Tanlu fault, which runs through the Bohai Sea, there are few major faults and fault zones in the coastal areas of the mainland. Major earthquakes will not occur along the coast. In my country's sea areas There are also very few island lakes and trenches, and the vertical differential movement in modern times is not obvious. It does not have such an up-and-down motion, and there is no up-and-down motion component, so it does not have the conditions for a major earthquake. Another factor is the depth of the sea. In other words, only a sea depth of one or two thousand meters will provide the possibility for a tsunami to occur. Our country has a well-developed and broad continental shelf, and the water is shallow, most of which are within 200 meters. Especially the average depth of the Bohai Sea is 18 meters. The average depth of the Yellow Sea is 44 meters, which is not conducive to the formation and spread of earthquakes and tsunamis. This is telling the truth and may involve certain risks, but in any case, it still has some basis.

So, what is the current status of tsunami disasters in our country? Transoceanic tsunamis occur in other parts of the world, and the energy transmitted from the deep sea to our sea areas will not pose a threat. For example, the tsunami in Chile At that time, it caused disasters to the Philippines and even Japan. However, when the tsunami reached Shanghai, the tide gauge station at the mouth of the Wusong River only recorded a tsunami wave height of 15 to 20 centimeters. It reached the shore, not the sea, but the sea. It's amazing inside, but it's amazing when we get together. It's already reached my point, and the waves are so high. The second local tsunami, I divided into two. I just talked about the transoceanic tsunami, and now it's a local tsunami. According to historical records, tsunamis have occurred in our country. In the past two thousand years, there have been ten earthquakes and tsunamis per year, with an average of one in every two hundred years. The most recent one was in 1876, which occurred in Beihai, Keelung, Taiwan Province on February 18. A tsunami occurred, killing hundreds of people.

Finally, I want to summarize it in two sentences. The first is man and nature. Human beings are not powerless in the face of tsunamis. What I emphasize is not to defeat it. We must be in harmony with it, but we can take action. What action? Let's make the next disaster less cruel. This is called disaster reduction.

In this way, our human wisdom can be brought into play, our global village can survive, and our future generations can develop. This is our wish. I think this should be an important revelation we can get, thank you all.