Small knowledge of great earthquakes

The structure of the earth is like an egg, which can be divided into three layers. The middle layer is the "yolk"-the core; In the middle is "egg white"-mantle; The outer layer is the "eggshell"-the shell. Earthquakes usually occur in the earth's crust. The earth is constantly rotating, and the interior of the crust is constantly changing. The resulting force led to the deformation, fracture and dislocation of the crust and strata, so an earthquake occurred.

Earthquake is a phenomenon in which the local medium in the earth ruptures rapidly, producing seismic waves, thus causing ground vibration in a certain range. Earthquake is the rapid vibration of the earth's surface, which was also called earthquake in ancient times. Just like wind, rain, lightning, landslides and volcanic eruptions, they are natural phenomena that often occur on the earth. Ground vibration is the most intuitive and common manifestation of earthquakes. Strong earthquakes at the bottom of the sea or in coastal areas will cause huge waves, which is called tsunami. Earthquakes are extremely frequent. There are about 5 million earthquakes around the world every year, which have a great impact on the whole society.

The place where seismic waves are emitted is called the source. The vertical projection of the source on the ground, and the point closest to the source on the ground is called the epicenter. It was the first place to receive vibration. The depth from the epicenter to the source is called the focal depth. Generally, the focal depth less than 70km is called shallow earthquakes, the depth of 70-300km is called Zhongyuan earthquake, and the depth greater than 300km is called deep earthquake. Earthquakes of the same size have different damage to the ground because of different focal depths. The shallower the source, the greater the damage, but the smaller the spread, and vice versa.

Destructive earthquakes usually occur in shallow earthquakes. For example, the focal depth of the Tangshan earthquake in 1976 was 12km.

The strongest ground motion of a destructive earthquake is called the extreme earthquake zone, which is often the area where the epicenter is located.

The distance from a place to the epicenter is called epicentral distance. Earthquakes with epicentral distance less than 1000 km are called near earthquakes, earthquakes with epicentral distance between 100- 1000 km are called near earthquakes, and earthquakes with epicentral distance greater than1000 km are called teleseisms. Among them, the farther the epicentral distance, the smaller the impact and damage.

The ground vibration caused by earthquake is a complex movement, which is the result of the joint action of longitudinal wave and shear wave. In the epicenter, longitudinal waves made the ground jump up and down. Shear waves make the ground shake horizontally. Because longitudinal waves travel faster and decay faster, while shear waves travel slower and decay slower, they are far from the epicenter, so you often can't feel jumping up and down, but you can feel horizontal shaking.

When a large earthquake occurs in a certain place, a series of earthquakes often occur within a period of time, the largest of which is called the main earthquake, the earthquake before the main earthquake is called the foreshock, and the earthquake after the main earthquake is called the aftershock.

Earthquakes have a certain temporal and spatial distribution law.

In terms of time, earthquakes have periodic phenomena of alternating active periods and quiet periods.

From a spatial point of view, the distribution of earthquakes has certain zones, called seismic zones, which are mainly concentrated in the Pacific Rim and Mediterranean-Himalayan seismic zones. The Pacific seismic belt almost concentrates more than 80% of the shallow earthquakes (0 km ~ 70 km) in the world, and all moderate earthquakes (70 km ~ 300 km) and deep earthquakes release about 80% of the total energy.

important

Magnitude refers to the magnitude of an earthquake and is an index to measure the intensity of an earthquake. It is determined by the energy released by each seismic activity measured by seismograph. The magnitude is usually represented by the letter M. At present, the standard of magnitude used in China is the international Richter scale, which is divided into 9 levels. Earthquakes with magnitude less than 2.5 are usually called small earthquakes, earthquakes with magnitude 2.5-4.7 are called inductive earthquakes, and earthquakes with magnitude greater than 4.7 are called destructive earthquakes. The magnitude difference per 1.0 and the energy difference are about 30 times; For every difference of 2.0, the energy difference is about 900 times. For example, an earthquake of magnitude 6 released energy equivalent to the atomic bomb dropped by the United States in Hiroshima, Japan. An earthquake of magnitude 7 is equivalent to 30 earthquakes of magnitude 6 or 900 earthquakes with magnitude difference of 0. 1, and the average difference of energy released is 1.4 times.

According to the magnitude, earthquakes can be divided into the following categories:

The magnitude of a weak earthquake is less than 3. This kind of earthquake is generally not easy to detect if the source is not very shallow.

The magnitude of the felt earthquake is equal to or greater than 3 and less than or equal to 4.5. People can feel this kind of earthquake, but generally it won't cause damage.

The magnitude of moderate-strong earthquakes is greater than 4.5 and less than 6. It belongs to an earthquake that can cause damage, but the degree of damage is also related to many factors such as focal depth and epicentral distance.

The magnitude of a strong earthquake is equal to or greater than 6. Among them, the magnitude greater than or equal to 8 is also called a giant earthquake.

Three elements of an earthquake:

Time, magnitude and epicenter of the earthquake

earthquake intensity

The damage caused by earthquakes of the same scale is not necessarily the same; The losses caused by the same earthquake are different in different places. In order to measure the degree of earthquake damage, scientists "made" another "ruler"-earthquake intensity. On the China Earthquake Intensity Table, people's feelings and the damage degree of ordinary houses are described, which can be used as the basic basis for determining the intensity. The factors affecting the intensity are magnitude, focal depth, distance from the focal point, ground conditions and stratigraphic structure.

Generally speaking, as far as the relationship between intensity and source and magnitude is concerned, the greater the magnitude, the shallower the source and the greater the intensity. Generally speaking, after the earthquake, the damage in the epicenter area is the heaviest and the intensity is the highest; This intensity is called epicentral intensity. From the epicenter to the surrounding areas, the earthquake intensity gradually decreased. So the earthquake has only one magnitude, but the damage caused by different regions is different. In other words, an earthquake can be divided into several regions with different intensities. This is the same reason that the degree of damage from far and near is different after the bomb explodes. The amount of explosives in the bomb is like magnitude; Bombs destroy different places as much as they do.

For example, on1February 1990 10, an earthquake of magnitude 5. 1 occurred in Changshu-Taicang. Some people say that Suzhou is level 4 and Wuxi is level 3, which is wrong. No matter where it is, it can only be said that an earthquake of magnitude 5. 1 occurred in Changshu-Taicang, but this time, the earthquake intensities in shaxi town, Taicang, Suzhou and Wuxi were 6 degrees, 4 degrees and 3 degrees respectively.

In China, the intensity is divided into 12 degrees, and the impact and damage of earthquakes with different intensities are generally as follows:

People below three degrees have no feelings, only instruments can record them;

Third, people have feelings in the dead of night;

People who sleep at four to five degrees will wake up and the chandelier will shake;

Six times the ship capsized and the house was slightly damaged;

Seven to eight degrees houses are damaged and cracks appear on the ground;

Nine to ten degrees houses collapsed and the ground was seriously damaged;

Eleven to twelve degrees of devastating damage;

For example, the 1976 Tangshan earthquake, with a magnitude of 7.6 and an epicenter intensity of 11 degrees. Affected by the Tangshan earthquake, the earthquake intensity in Tianjin is eight degrees, and that in Beijing is six degrees, only four to five degrees away from Shijiazhuang and Taiyuan.

seismism

When an earthquake occurs, the most basic phenomenon is the continuous vibration of the ground, mainly the obvious shaking.

People in the earthquake zone sometimes feel jumping up and down before they feel a big earthquake. This is because seismic waves travel from underground to the ground, and longitudinal waves arrive first. Shear waves then produce a large horizontal vibration, which is the main cause of earthquake disasters. 1960 during the Chile earthquake, the biggest shaking lasted for 3 minutes. The first disaster caused by the earthquake was the destruction of houses and structures, causing human and animal casualties. For example, in the 1976 Tangshan earthquake in China, 70% ~ 80% of buildings collapsed, causing heavy casualties.

Earthquakes also have a great impact on the natural landscape. The main consequence is that there are faults and ground fissures on the ground. The surface faults of large earthquakes often extend from tens to hundreds of kilometers, and often have obvious vertical and horizontal offsets, which can reflect the characteristics of structural changes at the source (see the Houwei earthquake and the San Francisco earthquake). However, not all surface faults are directly related to the motion of the source, and may also be caused by the secondary influence of seismic waves. Especially in areas with thick surface sediments, ground fissures often appear at the edge of hillsides, banks of rivers and both sides of roads. This is often due to topographical factors. Without support on one side, the topsoil is loose and cracked due to shaking. The shaking of the earthquake makes the topsoil sink, and the shallow groundwater will rise to the surface along the ground fissure, forming the phenomenon of sand blasting and water inrush. A big earthquake will change the local topography, or uplift or sink. Urban and rural roads are cracked, tracks are twisted and bridges are broken. In modern cities, water, electricity and communication are blocked due to the rupture of underground pipelines and the cutting of cables. The leakage of gases, toxic gases and radioactive substances will lead to secondary disasters such as fire, poisoning and radioactive pollution. In mountainous areas, earthquakes can also cause landslides and landslides, which often lead to the tragedy of burying villages and towns. The collapsed rocks blocked the river and formed an earthquake lake upstream. 1923 During the Great Kanto Earthquake in Japan, a mudslide occurred in Kanagawa Prefecture, which went down the valley as far as 5 kilometers.

Two major earthquake zones in the world

Pacific Rim Seismic Belt: It is distributed around the Pacific Ocean, like a huge garland, separating the mainland from the ocean.

Mediterranean-Himalayan seismic belt: From the Mediterranean Sea to the east, one branch passes through Central Asia to the Himalayas, then passes through the Hengduan Mountains in China to the south, passes through Myanmar, turns in an arc to the east, and reaches Indonesia, while the other branch extends from Central Asia to the northeast to kamchatka peninsula, showing scattered distribution.

The seismic activity in China is mainly distributed in 23 seismic zones in five regions. These five areas are: ① Taiwan Province Province and its adjacent waters; (2) Southwest China, mainly Tibet, western Sichuan and central and western Yunnan; (3) Northwest China, mainly distributed in Hexi Corridor of Gansu, Qinghai and Ningxia and the foothills of Tianshan Mountain; ④ North China, mainly located on both sides of Taihang Mountain, Wei Fen Valley, Yinshan-Yanshan area, Luzhong and Bohai Bay; ⑤ Southeast coastal areas such as Guangdong and Fujian. Taiwan Province province in China is located in the Pacific Rim seismic belt, Tibet, Xinjiang, Yunnan, Sichuan and Qinghai provinces are located in the Himalayan-Mediterranean seismic belt, and other provinces are located in related seismic belts.

Famous earthquake

The 11th earthquake in China.

1920 Haiyuan earthquake

1920 65438+February 16 at 20: 05: 53, a strong earthquake of magnitude 8.5 occurred in Haiyuan county, Ningxia. 240,000 people died, four cities were destroyed and dozens of county towns were damaged. This is the most extensive earthquake in the history of China.

1927 Gulang earthquake

1927 At 6: 32: 47 on May 23rd, a strong earthquake of magnitude 8 occurred in Gulang, Gansu, China. More than 40,000 people died. When the earthquake happened, the earth cracked, green and black water came out, and sulfur gas was brilliant, killing countless hungry people.

1932 changma earthquake

1932 65438+February 25th 10: 04: 27, a magnitude 7.6 earthquake occurred in Changmabao, Gansu, China. 70,000 people died. When the earthquake happened, there was yellow wind and white light "Pentium" on the loess wall; Dust emerged from the rocks, and Jiayuguan Tower, a famous historical site in China, collapsed. Xuefeng on the south bank of Shule River collapsed; The falling rocks in the Thousand Buddha Cave are rolling ... aftershocks are frequent and last for half a year.

1933 Diexi earthquake

On August 25th 1933, 15: 50: 30, a magnitude 7.5 earthquake occurred in Diexi Town, Maoxian County, Sichuan Province, China. When the earthquake happened, the ground was yellow and foggy, and the walls were gone. A shepherd boy flew over two mountains. The huge landslide cut off the Minjiang River and dammed it into a lake.

1950 chayu earthquake

1950 At 22: 09: 34 on August 5th, a strong earthquake of magnitude 8.6 occurred in Chayu County, Tibet, China. Hundreds of thousands of square kilometers of Himalayas are instantly unrecognizable: the Yarlung Zangbo River was cut into four sections in the landslide; The whole village was thrown across the river.

1966 Xingtai earthquake

Xingtai earthquake consists of two major earthquakes:15: 29 on March 8, 1966 14 seconds, a 6.8-magnitude earthquake occurred in Longyao County, Xingtai District, Hebei Province,1March 22, 1966 16, 19: 46 seconds, Ningjin County, Xingtai District, Hebei Province.

1970 Tonghai earthquake

65438+65438 0970+1:00: 341On 5 October, an earthquake of magnitude 7.7 occurred in Tonghai County, Yunnan Province, China. Death 1562 1 person, disability 3243 1 person. It is the second serious disaster with more than 10,000 deaths in China since the 1949 Yangtze River flood.

1975 Haicheng earthquake

On February 4th, 1975, 19: 36: 6, a magnitude 7.3 earthquake occurred in Haicheng county, Liaoning province, China. Because the earthquake was successfully predicted and prevented, it avoided more huge and heavy losses, so it was called a miracle in the history of earth science and world science and technology in the 20th century.

1976 Tangshan earthquake

1On July 28th, 976, at 3: 42: 54.2, a 7.8-magnitude earthquake struck Tangshan, Hebei Province, China. 242,000 people died and 1.6 million people were seriously injured. A heavy industrial city was destroyed, with a direct economic loss of more than 654.38 billion yuan, which was the biggest earthquake in the world in the 20th century.

1988 Lancang and Gengma earthquakes

1988 1 1: 03, 16 10. On October 6th, two major earthquakes of magnitude 7.6 (Lancang) and 7.2 (Gengma) occurred in China. The two earthquakes, which were120km apart, were only 13 minutes apart. Two county towns were razed to the ground, 4 105 people were injured and 743 people died, resulting in economic losses of 25 1 1 100 million yuan.

Wenchuan earthquake in 2008

On May 2008 12, 14: 28: 04.0, an earthquake of magnitude 8.0 occurred in Wenchuan County, Sichuan Province (3 1.0 N, 103.4 E), which was the strongest earthquake in China since the founding of the People's Republic of China, and the directly affected area reached 65,438+. As of May 22nd 19, 55,239 people were killed, 28 people were injured and 24,949 people were missing.

The strongest earthquake in the world since the 20th century.

On March 28th, 2005 (09: 00 Beijing time on the 29th), an earthquake measuring 8.5 on the Richter scale occurred off Sumatra Island, which is one of the eight strongest earthquakes in human history since 1900. The following are the basic information of 8 major earthquakes (in order of magnitude):

1, Chile earthquake (1May 22, 960): 8.9 on the Richter scale (later revised to 9.5 on the Richter scale). It happened in the waters of central Chile, and caused tsunami and volcanic eruption. The earthquake killed 5,000 people and left 2 million homeless.

2. Alaska Earthquake (1March 28th, 964): 9.2 on the Richter scale. The tsunami caused 125 deaths and property losses of 3 1 1 billion dollars. Strong earthquakes were felt in most parts of Alaska, Yukon, Canada and Colombia.

3. Alaska earthquake (1March 9, 957): 9. 1 on the Richter scale, which occurred in the waters near Andrea Island and Unac Island in Alaska, USA. The earthquake led to the eruption of Vesivedov volcano, which had been dormant for 200 years, and triggered a tsunami with a height of 15 meters, which spread as far as Hawaii Island.

4. (Parallel) Indonesia Earthquake (65438+February 26th, 2004): 9.0 on the Richter scale, which occurred in Aceh Province, Sumatra Island, Indonesia. The tsunami triggered by the earthquake swept through Sri Lanka, Thailand, Indonesia and India, leaving about 300,000 people missing or dead.

4. (tied) Russian earthquake (1952165438+1October 4th): 9.0 on the Richter scale. The tsunami triggered by the earthquake spread to the Hawaiian islands, but no casualties were caused.

5. Ecuador earthquake (190665438+1October 3 1): 8.8 on the Richter scale, which occurred off the coast of Ecuador and Colombia. The earthquake triggered a strong tsunami, resulting in more than 1000 deaths. Shocks were felt along the coast of Central America, San Francisco and Japan.

6. (Parallel) Indonesia Earthquake (March 28th, 2005): 8.7 on the Richter scale. The epicenter was located in the waters north of Sumatra Island, Indonesia, not far from the place where the 9.0-magnitude earthquake occurred three months ago. At present, it has caused 1000 deaths, but it has not caused a tsunami.

6. (tied) Alaska earthquake (1February 4, 965): 8.7 on the Richter scale. The earthquake triggered a tsunami as high as 10.7 meters, which swept the whole Sumatra island.

7. China Tibet Earthquake (1August 950 15): 8.6 on the Richter scale. More than 2000 houses and temples were destroyed. The Yarlung Zangbo River in India was the worst hit, with at least 1.500 deaths.

8. (tied) Russian earthquake (1February 3, 923): 8.5 on the Richter scale, which occurred in kamchatka peninsula, Russia.

9. (Parallel) Indonesia Earthquake (1February 3, 938): 8.5 on the Richter scale, which occurred in the waters near Banda, Indonesia. Earthquakes triggered tsunamis and volcanic eruptions, causing great losses to people and property.

10, (tied) Kuril Islands earthquake in Russia (196310/0/0/3): 8.5 on the Richter scale, and affected Japan and Russia.

1 1, Wenchuan earthquake, Sichuan, China (May 12, 2008): Richter scale 8, the epicenter was located in Wenchuan County, Aba Prefecture, which affected more than half of China and overseas. Heavy casualties and property losses.

The biggest earthquake in the world is19.5 Chile earthquake on May 22nd, 960.

The biggest earthquake in China was the August 1950 earthquake with magnitude 8.6 in Tibet.

1October 23rd, hua county, Shaanxi, M = 8 earthquake, with 65,438+65,438,0556,830 deaths.

Followed by the Tangshan earthquake of magnitude 7.5 on July 27th, 1976, with official data of 255,000 deaths (estimated to reach 655,000).

★ Encyclopedia of earthquake self-help

There are likely to be aftershocks after the earthquake, and the location of the aftershocks may not be very close to the source. So learning to save yourself is one of the most important measures after the earthquake.

When an earthquake happens, it is very important to keep a clear head and a calm attitude. Only when you are calm, it is possible to judge the magnitude and distance of an earthquake with the earthquake knowledge you usually learn. Recent earthquakes often start with ups and downs and then swing from side to side. The teleseism is not so bumpy, but it is mainly shaking from side to side, with clear voice and small vibration. Generally, small earthquakes and distant earthquakes do not have to flee.

The latest self-help advice: Don't hide under the table.

There are ten items of knowledge about earthquake prevention in Japan's Earthquake Handbook, the first of which clearly says "hide under solid furniture". Therefore, Japanese teachers firmly believe that the best way is to "hide under the table". This idea is based on the premise that the earthquake in Japan ended dozens of seconds later and the ceiling did not fall.

When the ceiling of a building collapses due to a strong earthquake, it will crush tables, beds and other furniture. If people hide inside, the consequences are unimaginable. If people hide next to the furniture in a low posture, the furniture can be forced by the collapsed objects first, so that the people next to it can get living space.

When you encounter an earthquake while driving, you should leave the car as soon as possible. Many people who died in the parking lot during the earthquake were crushed to death in the car, but the people between the two cars were not injured at all. When a strong earthquake occurs, if you are in the parking lot, don't stay in the car, lest the collapsed ceiling crush the car and cause injury; You should lie prone beside the car, because the falling smallpox will not directly hit people, and it may form a "living space" to increase your chances of survival.

School shock absorption

When you are in the playground or outdoors, you can squat down in place, protect your head with your hands, and pay attention to avoiding tall buildings or dangerous objects.

Don't go back to the classroom

Evacuation should be organized after the earthquake.

Never jump off a building! Don't stand outside the window! Don't go to the balcony

Classes should be held outdoors when necessary.

Family shock absorption

The earthquake warning time is short, and the indoor shock absorption is more real, and the triangular space formed after the collapse of indoor houses is often a relatively safe living place for people, which can be called shock absorption space. This mainly refers to the space formed by large collapsed bodies and supports.

Indoor triangular space is easy to form:

Under the edge of the kang, close to solid furniture;

Root and corner of interior wall;

Kitchen, bathroom, storage room and other small places.

Shock absorption in public places

Listen to the instructions of the field staff, don't panic, don't rush to the exit, avoid crowding, avoid crowds, and avoid being pushed to the wall or fence.

In theatres, gymnasiums, etc:

Pay attention to avoid hanging objects such as chandeliers and electric fans;

Protect your head with a schoolbag, etc.

After the earthquake, listen to the command of the staff and evacuate in an organized manner.

In shopping malls, bookstores, exhibitions, subways, etc.:

Choose solid counters and commodities (such as low furniture, etc.). ) or pillars, and squat down in the inner corner, and protect your head with your hands or other things; Avoid glass doors and windows, glass windows or counters; Avoid tall and unstable shelves or shelves with heavy objects and fragile items; Avoid tall or hanging objects, such as billboards and chandeliers.

In a moving electric (automobile) vehicle:

Grasp the handrail to avoid falling or bumping; Lower your center of gravity and hide near your seat.

Don't get off until the earthquake has passed.

Outdoor shock absorption

Field selection of outdoor shock absorber;

Squat or get down to avoid falling;

Don't run around and avoid crowded places;

Don't go back indoors casually.

Avoid tall buildings or structures:

Buildings, especially those with glass curtain walls;

Crossing bridges and overpasses;

Under tall chimneys and water towers.

Avoid dangerous objects, towering or hanging objects:

Transformer, telephone pole, street lamp, etc. ;

Billboards, cranes, etc.

Avoid other dangerous places:

Narrow streets;

Dangerous old houses, dangerous walls;

Under the parapet, high gate face and awning;

Bricks, wood and other things piled up.

Workshop worker shock absorption

Workshop workers can hide under cars, machine tools and tall equipment, and don't panic and run around. Workers in special posts should first close the valves of flammable, explosive and toxic gases, reduce the temperature and pressure of high-temperature and high-pressure pipelines in time, and close the operation equipment. Most people can leave the work site, and a few people can stay at the site to monitor the danger at any time under the premise of safety protection, deal with possible accidents in time and prevent secondary disasters.

Emergency shock absorption of running vehicles in earthquake.

(1) The driver should slow down as soon as possible and brake gradually;

(2) Passengers (especially on the train) should firmly grasp the handle, post or seat with their hands, and pay attention to prevent luggage from falling from the luggage rack and hurting people. People facing the driving direction should put their arms on the seat cushion in front, protect their faces, lean toward the passage, and protect their heads with their hands; People with their backs to the direction of driving should protect the back of their heads with their hands, raise their knees to protect their abdomen, tighten their bodies and take a defensive posture.

Emergency shock absorption of people in buildings during earthquakes.

Once an earthquake happens, keep a clear head, judge the vibration in time, and never jump off a building in a panic. Secondly, you can hide under solid furniture, or in a corner, or you can move to a kitchen, toilet and small room with many load-bearing walls for temporary shelter. Because these places have strong binding force, especially the pipeline has good supporting force and large seismic coefficient after treatment. In a word, according to the building layout and indoor conditions, we can evaluate the situation and find safe spaces and passages to avoid and reduce casualties.

Emergency shock absorption in the store during earthquake

The department store kept calm when it was hit by an earthquake. Due to the panic of people and the falling of goods, the refuge passage may be blocked. At this time, you should hide near big pillars and big commodities (avoid commodity display cabinets), or hide in an unobstructed passage, and then bend down and wait for the earthquake to subside. In the upstairs position, in principle, it is best to transfer to the ground floor. However, stairs are often the weak parts of buildings in earthquake resistance. Therefore, we must seize the opportunity to escape. Attendants should organize the masses to avoid nearby and evacuate safely after the earthquake.

Three strategies for shock absorption of high-rise buildings

Strategy 1: Stay calm during the earthquake and go outdoors after the earthquake. This is an international standard for earthquake prevention. Many earthquake examples at home and abroad show that people are most likely to be killed or injured when they enter or leave buildings in a short time. Therefore, experts remind that indoor shock absorption conditions are good, and indoor shock absorption must be selected first. If the building has poor earthquake resistance, try to run out of the room.

According to the relevant national standards, residential buildings in Beijing should have the ability to resist the damage of the 8-degree earthquake. Don't panic when an earthquake happens, keep your vision wide and moving so that the camera can move. Especially don't stay in bed; Don't run to the balcony; Don't run to the corridor where there are many people; Don't jump off a building; Don't use the elevator. If there is an earthquake, you should leave the elevator as soon as possible. If the door won't open, hold your head down. In addition, it is necessary to immediately put out the fire and cut off the power supply to prevent burns, electric shocks and fires.

Strategy 2: The position of shock absorber is very important. If you live in a building shock absorber, you can judge the situation according to the building layout and indoor conditions and find a safe space to escape. It is best to find a place where a triangular space can be formed. It's safer to squat next to the heater, which is very important. The reticular structure and elasticity of metal pipes are not easy to be torn, and it is not easy to be thrown out even if there is a big earthquake. The heating pipe is well ventilated, which is not easy to cause suffocation; The water stored in the pipeline can also prolong the survival period. More importantly, trapped people can send information to the outside world by tapping the heating pipe, and the location of the heating near the external wall is conducive to getting help as soon as possible.

Hiding in a small room like kitchen and bathroom, pay special attention to stay away from stoves, gas pipes and fragile dishes. If the kitchen and bathroom are located in the corner of the building and the partition wall is thin-walled, don't choose it as the best location for shock absorption. In addition, don't get into cabinets or boxes, because once people get into them, they will immediately lose their mobility, their vision will be blocked, and their limbs will be tied, which not only misses the opportunity to escape, but also is not conducive to being rescued; Poor lying posture increases the plane area of human body, and the probability of being hit is five times greater than that of standing posture, making it difficult to maneuver.

Strategy 3: near water is not close to fire, but outside rather than inside. This is an important principle to ensure timely assistance from others in urban earthquakes. Stay away from gas stoves, gas pipelines and household appliances; Don't choose the internal position of the building, try to be close to the external wall, but don't hide under the window; Try to get close to the water source. Once trapped, try to contact the outside world. In addition to using a mobile phone, you can also use water pipes and radiators or turn on a flashlight.