How to protect yourself when the tsunami comes?
At the end of 2004, an undersea earthquake triggered a huge tsunami, which brought great disasters to Indonesia, Bangladesh, India, Maldives and other countries, causing more than 6,543,800 casualties. Tsunamis can reach 3,000 to 5,000 kilometers away, causing casualties in Somalia more than 4,000 kilometers away. On the high seas, a tsunami can move forward at a speed of 800 kilometers per hour like a commercial plane. Therefore, it takes two to three hours for it to cause harm to people. This provides people with an opportunity for early warning, but countries along the Indian Ocean lack such an early warning mechanism. Although the disaster has happened, it is still having a profound and extensive impact, and the victims in the affected countries are still suffering from the disaster.
In the course of the disaster, a series of sad stories and self-help stories appeared. For example, a young woman was on vacation at the seaside with her boyfriend. When the tide came, she grabbed a palm tree and escaped, but her boyfriend was swept away by the tide. An Indian grandmother with her little grandson drifted 60 kilometers on the board and was finally rescued. There is also a mother who is on holiday in Crabbie Beach, Thailand. Facing the 30-foot-high waves, she rushed to the coast to save her children. An Indonesian father named Bolton tied several children to a tree with a towel to avoid being washed away by the waves. His three children escaped safely ... These touching stories not only shocked and touched us, but also told teenagers how to deal with and save themselves in the face of disasters.
(1) What is a tsunami?
Tsunami is a violent movement of seawater, which is extremely destructive. The wild waves caused by this wave movement are shocking and surging. The waves it rolls up can reach tens of meters high and contain huge energy. After landing on the beach, it is invincible and often seriously damages life and property. Submarine earthquakes, volcanic eruptions, underwater collapses and landslides can all cause tsunamis. Among them, the submarine earthquake is the main cause of tsunami, and all catastrophic tsunamis in history are caused by submarine earthquake.
When the tsunami is in the open sea, it is generally ignored because of the small water depth and wave fluctuation. In the shallow water area on the shore, the huge energy makes the waves suddenly increase, forming a water-blocking wall of more than ten meters or even higher, and rushing to the land like an avalanche. It is so powerful that it can completely destroy the buildings on the shore. Everywhere I went, I was devastated and in a mess, posing a great threat to human life.
When a tsunami spreads to the coast, there are generally two manifestations: the first is that the seawater in the coast, island or bay is abnormally ebbing or the river is dry, and then the seawater suddenly sweeps over and rushes to the land; The second is the sharp rise of sea water, which suddenly forms a water wall of tens of meters high and comes to the coastal land with a rumbling noise, and then the sea water suddenly recedes.
(2) Signs and preventive measures before the tsunami.
The earliest signal of earthquake and tsunami is strong ground vibration, and there is a time difference between the arrival of earthquake wave and tsunami, which is beneficial to people's prevention.
If you find that the tide fluctuates suddenly and abnormally, the sea level drops obviously or there are huge waves coming, you should leave the shore as soon as possible.
When the sea water receded abnormally before the tsunami, many marine life such as fish and shrimp were often left in the shallows, and the scene was spectacular. Don't pick up fish or go sightseeing at this time. You should leave the coast quickly and move to the inland highlands.
In the event of a tsunami, ships sailing at sea should not return to port or dock, but should immediately sail to the deep sea area, which is safer than the coast.
(3) How to help each other after the tsunami?
If you fall into the water in the tsunami, try to catch floating objects such as wooden boards to avoid colliding with other hard objects.
Don't raise your hand in the water, don't struggle, try to reduce your movements, and you can float on the water. This can not only avoid sinking, but also reduce unnecessary physical consumption.
Don't take off your clothes when the sea temperature is low.
Try not to swim to avoid excessive heat loss in the body.
Don't drink sea water. Seawater can not only quench thirst, but also make people hallucinate, leading to mental disorder and even death.
Try to get close to other drowning people, which is not only convenient to help and encourage each other, but also easier for rescuers to find because of the expansion of the target.
When people are immersed in seawater for a long time, the loss of heat will lead to a drop in body temperature. After the drowning person is rescued ashore, it is best to put it in warm water to restore his body temperature. If there are no conditions, he should also try to wrap quilts, blankets, coats and so on to keep warm. Be careful not to take local heating or massage, and don't drink water for drowning people. Drinking water can only make the heat dissipate faster. Just give the drowning person some sugar water properly, which can replenish the water and energy in the body.
If the drowning person is injured, first aid measures such as hemostasis, dressing and fixation should be taken, and the seriously injured person should be sent to the hospital for treatment in time.
Remember to remove the inhalants from the nose, mouth and abdomen of the drowning person in time. The specific method is: put the belly of the drowning person on his thigh, press it from behind, and suck out the numbers such as seawater. If heartbeat and breathing stop, mouth-to-mouth resuscitation and cardiac compression should be performed alternately immediately.
Earthquake disaster is a kind of natural disaster that directly endangers human survival. For a long time, mankind has accumulated quite rich experience in the process of fighting earthquake disasters.
At ordinary times, we should establish "I would rather not shake for a thousand days." The concept of an earthquake that cannot be prevented for a day; Formulate family earthquake-proof and shock-proof plans; Don't put heavy objects on high places. Furniture should be placed in the weak part of the wall. Don't put anything under the table and bed. Put the bed by the door. Arrange emergency items in an orderly manner, and remember the positions of water, electricity and gas switches and evacuation passages; If you are in a short-term earthquake prediction area, you should prepare food, medicine and emergency supplies.
The scene of a big earthquake is unimaginable for people who have never experienced a strong earthquake: when people hear or see terrible, strong and strange ground sounds or light, they will feel great fear; When the ground vibrates strongly, some people sit unsteadily and stand unsteadily, and the house they live in shakes violently and collapses instantly; When the doors and windows of the living room are deformed, and some people are eager to escape, it is difficult to open them, and the living room items fall and dump, making a loud noise; It was just dark when the earthquake happened. Someone was sleeping in vinegar, and suddenly there was no electricity or water, and it was dark around. When the air is dirty and full of dust and smoke, it is suffocating; When people are out of control and unable to act independently, run or stand unsteadily; When someone is shaken down or even feels thrown up and weightless, what kind of emergency action will you take when you feel the same way?
1976 when Tangshan earthquake of magnitude 7.8, the number of people buried was as high as 570,000. Through self-help and mutual rescue, the number of people who escaped from danger reached about 450 thousand, accounting for 79%. According to the investigation of 947 survivors of Tangshan earthquake, 258 of them took anti-seismic measures, and 188 people successfully escaped from danger safely, accounting for 72% of those who took anti-seismic measures.
If we can face it correctly in such a harsh environment and take self-help and mutual rescue measures, we may survive.
I. Emergency response
1, earthquake early warning phenomenon
Although the earthquake is threatening, it may bring some macroscopic phenomena of impending earthquake to people in a short time, which is the so-called earthquake early warning phenomenon. There are mainly initial ground motion, ground sound and ground light.
1) The initial ground vibration: people feel that the earth is "trembling";
2) Earthquake: it lasts for several seconds to several minutes, and it is strong and strange, such as thunder, the roar of cannons or machines, the roar of strong winds, and the sound of trees breaking. It seems that there is wind, but the treetops and leaves are still;
3) Ground light: lasting for several seconds to several minutes, bright and horrible, colorful, flaky, banded, columnar, spherical, etc. , as bright as day; But the tree has no shadow.
The warning time of a major earthquake is generally more than ten seconds. The ground moves first (tremors first), accompanied by ground sound and ground light; Then move (shake back); Then the house collapses, which will cause casualties and property losses.
2. Distance and intensity of earthquakes
As mentioned earlier, during an earthquake, people feel "shaking first" and then "swinging". With the increase of epicentral distance, the time difference between "tremor" and "shaking" will be lengthened and the intensity will be weakened. Outside a certain range, people will not feel "tremor", but only "shaking".
Therefore, if you feel that the tremor is not obvious during the earthquake, but only slightly shaking, it means that the earthquake is far away from you or has just begun. Generally, there is a "warning time" of more than ten seconds, so you can choose a suitable shock-proof place; On the contrary, if you feel shaking up and down and shaking violently during the earthquake, it means that the earthquake is close to you or has been going on for some time; If the tremor and shaking are not too strong, it means that the magnitude is not big.
3. Instant selection
(1) Indoor shock absorption
After the collapse of indoor houses, the triangular space formed by a large number of collapsed bodies and supports is often a safe place for people to live, which is called earthquake-proof space or "safety island". For example, under the kang, under the bed, under the table, near solid furniture; Interior wall corner; Kitchen, bathroom, storage room and other small places (Figure 2- 10).
For example, Chen, who lived on the 4th floor of Zone VII during the Tangshan earthquake, said that the earthquake happened around 3: 30 in the middle of the night and he was about to come out of the toilet. At that time, I was awake and squatted down with my hand over my head. Later, I heard the sound of the house collapsing. The house fell down, and when it was less than two stories high, the roof was pulled aside, the toilet wall fell down, and the precast slab at the foot sank, and I fell on the ruins and squatted. All the big rooms in this building collapsed, only the small rooms, kitchen and toilet on the third and fourth floors collapsed. Most of the survivors of the whole building hid in a small room.
Note: the places that are not conducive to shock absorption are beds and unsupported floors; Don't take the elevator during an earthquake, and generally don't choose to jump off a building as a shock absorber.
(2) Outdoor shock absorption
Plan to choose an open and safe place to reach the highest point.
Attention: avoid tall buildings, chimneys, hutongs, overhead pipelines, high-voltage lines, transformers, bridges, steep slopes, dangerous rocks and rolling stones, and river banks. The car driver intends to brake in a safe zone, and the train driver intends to take emergency braking measures.
For example, Sun, who lived in a bungalow during the Tangshan earthquake, said that it was sultry that day. She got up in the middle of the night to take a shower and then lay down and couldn't sleep. Suddenly she heard a sound like a strong wind (earth sound), got up and closed the window, but there was no wind. Seeing the red light (earth light) outside the window, she thought the ammunition depot was on fire and ran outside. She ran out and came back to call her husband and son. Just then, she heard a noise under her feet, felt the ground shaking (at first it was shaking) and realized the earthquake. Because the door was deformed and couldn't be opened, four people jumped out of the window and the house collapsed as soon as they got into the yard.
(3) Shock absorption at school and at work
Planning to hide under a table or large equipment; Special departments should operate according to the earthquake emergency plan.
Attention: Turn off the machine, flammable and explosive toxic valves and cut off the power supply.
(4) Shock absorption in public places
It is planned to be selected under the row chairs, at the foot of the stage, under the desk, beside the podium and under the counter (Figure 2- 1 1).
Attention: Stop all normal activities; Evacuate in an orderly manner to avoid crowding.
Fig. 2- 1 1 The correct way to reduce vibration in schools, public places and outdoors.
For example, during the Tangshan earthquake, Zhang Shiqin, a cadre of Tangshan Iron and Steel Plant in X-zone, was eating in the canteen. That night (about 3: 30), before he had taken a few bites, he heard a muffled sound, like thunder (ground sound), felt the ground shaking (initial ground vibration) and realized that an earthquake had occurred. Just after running 5 meters, the light went out, and it was dancing and swaying. There was no root at the foot, so I couldn't leave. The canteen door is relatively narrow, and only one person can pass through it at ordinary times. There were so many people in the earthquake that no one could get out. As soon as the front leg stepped out when I touched the door, the whole canteen was pinned down. The inside of the door is the worst, and many people are buried, which is terrible. It took only ten seconds from hearing the noise to being buried. There were 30 to 40 people eating in the canteen, and a dozen people ran out. An old man didn't run away or get hurt under the table. The remaining twenty people were smashed to death at the door.
(5) "to be determined" method
An old man who personally experienced the Haiyuan M8.5 earthquake in 1920 described: "When you feel the earthquake indoors, you should quickly lie down on the edge of the kang, face down, head against the wall, arms crossed on your chest, right hand holding your left arm, the concave part above your nose between your eyes resting on your arm, close your eyes and mouth, and breathe through your nose" (Figure 2 2- 10)
In addition, you can squat or sit down, curl up and lower your center of gravity during an earthquake; You can also catch solid objects to prevent injuries caused by falling.
Second, avoid difficulties.
Post-earthquake self-help refers to the measures that people take to eliminate danger and save lives by using their own conditions after the earthquake.
1, post-earthquake dilemma
After the strong earthquake, people's daily calm was broken.
(1) lost contact.
If family members are killed or injured, or relatives cannot be found; Or alone, unable to contact family; Or you can't go home without transportation. All this has brought great mental trauma to the survivors.
(2) Dangerous situation
The earthquake hurt my body; Or trapped in tall buildings, broken bridges, or other dangerous environments; Or buried in the ruins.
(3) Secondary disasters
For example, fires, gas leaks and explosions caused by earthquakes; Social security is chaotic, and bad guys take advantage of the fire to rob and commit crimes.
2. Emergency survival
(1) Burying countermeasures
If you are unfortunately buried in the earthquake, you must not have a nervous breakdown. You should summon up courage and confidence to survive, do everything possible to keep breathing normally and wait for help. Try to show your hands and head; Save your strength. Don't shout, don't act reluctantly. When you hear someone on the ground, do everything possible to send out a distress signal. Prevent dust choking and suffocation; If you can't get in touch with the outside world, you should analyze and judge where you are buried, open the passage and find a shortcut to escape. In case it takes time and effort to escape, it should be stopped immediately; Looking for food, water and medicine, you can drink urine to survive when you are in danger of dying of thirst; Strive to expand the living space; Look for sharp tools to keep the air flowing.
For example, after the Tangshan earthquake, five miners, including Chen Shuhai of Kailuan Coal Mine, were trapped underground because of the collapse of the coal mine. They lived on the water in the mine and were finally rescued after 15 days and nights. Another example is the Tangshan earthquake, when Tian Huiying was only 12 years old. Her family was buried in the collapsed building, and her parents and brother died one after another. She always remembers that her mother told her to "hold on no matter what!" "Take care of my nephew, really thirsty, you feed him some saliva. He tried to keep his urine, which was very effective when he was thirsty. " So he persisted in the ruins for three days and nights and was finally rescued.
(2) to prevent new infringement
After the earthquake, aftershocks continue, and the living environment may deteriorate further, so we should be psychologically prepared; Waiting for rescue requires some time and enough patience; Try to improve the living environment and try to escape; Cover your nose and mouth with wet clothes when you smell toxic and harmful gases or dust is too heavy; Try to avoid hanging unstable and easily collapsed objects above your body; Expand and protect the living space and strive to support the ruins; Don't use water and electricity casually, and don't use naked flames, because there may be flammable gases in the air; Eyes in the dark for a long time cannot be stimulated by strong light immediately; Eat in water step by step to avoid gastrointestinal damage.
(3) Get out of danger quickly
Evacuate the dangerous house and go to an open place. When leaving, put out the open flame, turn off the gas switch and cut off the power supply and fire source; Evacuate classrooms or public places under the command of relevant personnel to prevent injuries caused by crowding; Don't go back to the dangerous house easily, beware of the threat of aftershocks. Get together with your family as soon as possible and act according to the family plan before the earthquake, or contact the service office and go to the specified evacuation place for shock absorption.
In the event of floods, landslides and other situations that endanger the safety of houses, it is necessary to transfer them in time.
How to avoid a tornado?
Tornado is a kind of strong vortex with almost vertical axis, accompanied by strong thunderstorm. It is shaped like a funnel-shaped rotating cloud column. When it happens on the water surface, it often rises in a column after absorbing water, like "dragon absorbing water", which is called waterspout. When it appears on land, it is called a tornado. Tornadoes are characterized by:
The range of (1) is small. Generally, the diameter of waterspout is between10m and100m. The land dragon roll is a little bigger, but it is only 100 ~ 1000 meters.
(2) Life is short. Usually only a few minutes, no more than a few hours.
(3) The central air pressure is extremely low. It is estimated that the central air pressure can be as low as 400 hectopascals. Even as high as 200 hectopascals.
(4) The wind is strong. The wind speed near the tornado center can reach100 ~ 200m/s.
(5) destructive power. Tornadoes often pull up trees, overturn vehicles, destroy buildings and sometimes suck people away, which is very harmful.
The tornado struck suddenly and violently, and the wind force produced was the strongest on the ground. In the United States, the number of deaths caused by tornadoes is second only to lightning every year. Its damage to buildings is also quite serious, often devastating. Under the attack of a strong tornado, the roof of the house will fly like a glider. Once the roof is swept away, the rest of the house will collapse. 1995 A tornado occurred in Adelmo, Oklahoma, USA. Heavy objects such as roofs were blown dozens of miles away, and lighter fragments flew more than 300 kilometers before landing. Most of the debris falls on the left side of the tornado passage, and there are often obvious landing areas according to different weights.
Globally, tornadoes mainly occur in mid-latitude areas of 20-50 degrees. There are more than 1000 tornadoes recorded every year in the world, among which the United States has an average of 800 tornadoes every year, which is called the "Tornado Kingdom". Most provinces (autonomous regions and municipalities) in China have traces of tornadoes, with an average frequency of less than 100 times per year, and most of them are concentrated in the eastern half, with relatively more in Jiangsu, Shanghai, Anhui, Zhejiang, Shandong, Hubei, Guangdong and other provinces in East China. Tornadoes generally appear from May to September, mostly in the afternoon to evening.