Where are earthquakes most common? Earth disasters - earthquakes

Major earthquakes have occurred throughout human history, with the earliest recorded dating back almost 2,000 BC. But it is only in the last century that our technological capabilities have reached the point where the impact of these disasters can be fully measured. Our ability to study earthquakes has made it possible to avoid catastrophic casualties, such as in the case of a tsunami, when people have the opportunity to evacuate a potentially dangerous area. But unfortunately, the warning system does not always work. There are several examples of earthquakes where the greatest damage was caused by the subsequent tsunami, and not by the earthquake itself. People have improved building standards and improved early warning systems, but they have never been able to completely protect themselves from disasters. There are many different ways to estimate the strength of an earthquake. Some people rely on the Richter scale, others on the number of deaths and injuries, or even the monetary value of the damaged property. This list of the 12 strongest earthquakes combines all of these methods in one.

Lisbon earthquake

The Great Lisbon Earthquake struck the Portuguese capital on November 1, 1755, causing enormous destruction. They were made worse by the fact that it was All Saints' Day and thousands of people attended mass in the church. Churches, like most other buildings, could not withstand the elements and collapsed, killing people. Subsequently, a tsunami 6 meters high hit. An estimated 80,000 died due to fires caused by the destruction. Many famous writers and philosophers dealt with the Lisbon earthquake in their works. For example, Emmanuel Kant, who tried to find a scientific explanation for what happened.

California earthquake

A major earthquake struck California in April 1906. Etched into history as the San Francisco earthquake, it caused damage to a much wider area. Downtown San Francisco was destroyed by a huge fire that followed. Initial figures mentioned 700 to 800 dead, although researchers claim the actual death toll was more than 3,000. More than half of San Francisco's population lost their homes as 28,000 buildings were destroyed by the earthquake and fires.

Messina earthquake

One of Europe's largest earthquakes struck Sicily and southern Italy in the early hours of December 28th, 1908, killing an estimated 120,000 people. The main epicenter of the damage was Messina, which was virtually destroyed by the disaster. The magnitude 7.5 earthquake was accompanied by a tsunami that hit the coast. A recent study suggested that the size of the waves was so huge because of an underwater landslide. Much of the damage was due to the poor quality of buildings in Messina and other parts of Sicily.

Haiyuan earthquake

One of the deadliest earthquakes on the list occurred in December 1920, with its epicenter in Haiyuan Chingya. At least 230,000 people died. Measuring 7.8 on the Richter scale, the earthquake destroyed almost every home in the region, causing significant damage to major cities like Lanzhou, Taiyuan and Xi'an. Incredibly, waves from the earthquake were visible even off the coast of Norway. According to a recent study, Haiyuan was the strongest earthquake to hit China during the 20th century. Researchers have also questioned the official death toll, suggesting there may have been more than 270,000. This number represents 59 percent of the population in the Haiyuan area. The Haiyuan earthquake is considered one of the most destructive natural disasters in history.

Chilean earthquake

A total of 1,655 were killed and 3,000 were injured after a magnitude 9.5 earthquake struck Chile in 1960. Seismologists called it the strongest earthquake ever to occur. 2 million people were left homeless and economic losses amounted to $500 million. The force of the earthquake caused a tsunami, with casualties in places as far away as Japan, Hawaii and the Philippines. In some parts of Chile, waves have moved building ruins 3 kilometers inland. The massive Chilean earthquake of 1960 caused a giant rupture in the ground extending over 1,000 kilometers.

Earthquake in Alaska

On March 27th, 1964, a strong 9.2 earthquake struck the Prince William Sound region of Alaska. As the second most powerful earthquake on record, it caused a relatively low number of deaths (192 deaths). However, significant property damage occurred in Anchorage, and tremors were felt in all 47 US states. Due to significant improvements in research technology, the Alaska earthquake has provided scientists with valuable seismic data, allowing them to better understand the nature of such events.

Kobe earthquake

In 1995, Japan was hit by one of its most powerful earthquakes when a magnitude 7.2 shock struck the Kobe region in south-central Japan. Although it was not the worst ever seen, the devastating impact was felt by a significant portion of the population—an estimated 10 million people living in the densely populated area. A total of 5,000 were killed and 26,000 were injured. The US Geological Survey estimated damage at $200 billion, with infrastructure and buildings destroyed.

Sumatra and Andaman earthquake

The tsunami that struck across the Indian Ocean on December 26, 2004 killed at least 230,000 people. It was caused by a large undersea earthquake off the west coast of Sumatra, Indonesia. His strength was measured at 9.1 on the Richter scale. The previous earthquake in Sumatra occurred in 2002. It is believed to have been a seismic pre-shock, with several aftershocks occurring throughout 2005. The main reason for the huge number of casualties was the lack of any early warning system in the Indian Ocean capable of detecting an approaching Tsunami. A giant wave reached the shores of some countries, where tens of thousands of people died, for at least several hours.

Kashmir earthquake

Jointly administered by Pakistan and India, Kashmir was hit by a magnitude 7.6 earthquake in October 2005, killing at least 80,000 people and leaving 4 million homeless. Rescue efforts were hampered by conflicts between the two countries fighting over the territory. The situation was aggravated by the rapid onset of winter and the destruction of many roads in the region. Eyewitnesses spoke of entire areas of cities literally sliding off cliffs due to the destructive elements.

Disaster in Haiti

Port-au-Prince was hit by an earthquake on January 12, 2010, leaving half the capital's population without their homes. The death toll is still disputed and ranges from 160,000 to 230,000. A recent report highlighted that as of the fifth anniversary of the disaster, 80,000 people continue to live on the streets. The impact of the earthquake has caused severe poverty in Haiti, which is the poorest country in the Western Hemisphere. Many buildings in the capital were not built in accordance with seismic requirements, and the people of the completely destroyed country had no means of subsistence other than the international aid provided.

Tohoku earthquake in Japan

The worst nuclear disaster since Chernobyl was caused by a magnitude 9 earthquake off the east coast of Japan on March 11, 2011. Scientists estimate that during the 6-minute earthquake of colossal force, 108 kilometers of the seabed rose to a height of 6 to 8 meters. This caused a large tsunami that damaged the coast of Japan's northern islands. The Fukushima nuclear power plant was badly damaged and efforts to salvage the situation are still ongoing. The official death toll is 15,889 dead, although 2,500 people are still missing. Many areas have become uninhabitable due to nuclear radiation.

Christchurch

The worst natural disaster in New Zealand's history claimed 185 lives on February 22, 2011, when Christchurch was hit by a powerful 6.3 magnitude earthquake. More than half of the deaths were caused by the collapse of the CTV building, which was built in violation of seismic codes. Thousands of other houses were also destroyed, including the city's cathedral. The government declared a state of emergency in the country so that rescue efforts could proceed as quickly as possible. More than 2,000 people were injured, and reconstruction costs exceeded $40 billion. But in December 2013, the Canterbury Chamber of Commerce said that three years after the tragedy, only 10 per cent of the city had been rebuilt.

The strongest earthquakes throughout human history have caused colossal material damage and caused a huge number of casualties among the population. The first mention of tremors dates back to 2000 BC.
And despite the achievements of modern science and the development of technology, no one can still predict the exact time when the elements will strike, so quick and timely evacuation of people often becomes impossible.

Earthquakes are natural disasters that kill the most people, much more than, for example, hurricanes or typhoons.
In this rating we will talk about the 12 most powerful and destructive earthquakes in human history.

12. Lisbon

On November 1, 1755, a powerful earthquake occurred in the capital of Portugal, the city of Lisbon, later called the Great Lisbon Earthquake. A terrible coincidence was that on November 1 - All Saints' Day, thousands of residents gathered for mass in the churches of Lisbon. These churches, like other buildings throughout the city, could not withstand the powerful shocks and collapsed, burying thousands of unfortunates under their rubble.

Then a 6-meter tsunami wave rushed into the city, covering the surviving people rushing in panic through the streets of destroyed Lisbon. The destruction and loss of life were colossal! As a result of the earthquake, which lasted no more than 6 minutes, the tsunami it caused and numerous fires that engulfed the city, at least 80,000 residents of the Portuguese capital died.

Many famous figures and philosophers touched on this deadly earthquake in their works, for example, Immanuel Kant, who tried to find a scientific explanation for such a large-scale tragedy.

11. San Francisco

On April 18, 1906, at 5:12 am, powerful tremors shook sleeping San Francisco. The force of the tremors was 7.9 points and as a result of the strongest earthquake in the city, 80% of the buildings were destroyed.

After the first count of the dead, authorities reported 400 victims, but later their number increased to 3,000 people. However, the main damage to the city was caused not by the earthquake itself, but by the monstrous fire it caused. As a result, more than 28,000 buildings throughout San Francisco were destroyed, with property damage amounting to more than $400 million at the exchange rate of that time.
Many residents themselves set fire to their dilapidated houses, which were insured against fire, but not against earthquakes.

10. Messina

The largest earthquake in Europe was the earthquake in Sicily and Southern Italy, when on December 28, 1908, as a result of powerful tremors measuring 7.5 on the Richter scale, according to various experts, from 120 to 200,000 people died.
The epicenter of the disaster was the Strait of Messina, located between the Apennine Peninsula and Sicily; the city of Messina suffered the most, where practically not a single surviving building remained. A huge tsunami wave, caused by tremors and amplified by an underwater landslide, also caused a lot of destruction.

Documented fact: rescuers were able to pull two exhausted, dehydrated, but alive children from the rubble, 18 days after the disaster struck! The numerous and extensive destructions were caused primarily by the poor quality of buildings in Messina and other parts of Sicily.

Russian sailors of the Imperial Navy provided invaluable assistance to the residents of Messina. The ships as part of the training group sailed in the Mediterranean Sea and on the day of the tragedy ended up in the port of Augusta in Sicily. Immediately after the tremors, sailors organized a rescue operation and thanks to their brave actions, thousands of residents were saved.

9. Haiyuan

One of the deadliest earthquakes in human history was the devastating earthquake that struck Haiyuan County, part of Gansu Province, on December 16, 1920.
Historians estimate that at least 230,000 people died that day. The force of the tremors was such that entire villages disappeared into the faults of the earth’s crust, and large cities such as Xi’an, Taiyuan and Lanzhou were greatly damaged. Incredibly, strong waves formed after the disaster were recorded even in Norway.

Modern researchers believe that the death toll was much higher and totaled at least 270,000 people. At that time, this was 59% of the population of Haiyuan County. Several tens of thousands of people died from the cold after their homes were destroyed by the elements.

8. Chile

The earthquake in Chile on May 22, 1960, considered the strongest earthquake in the history of seismology, measured 9.5 on the Richter scale. The earthquake was so powerful that it caused tsunami waves more than 10 meters high, which covered not only the coast of Chile, but also caused enormous damage to the city of Hilo in Hawaii, and some of the waves reached the coasts of Japan and the Philippines.

More than 6,000 people died, most of whom were hit by the tsunami, and the destruction was unimaginable. 2 million people were left homeless and the damage amounted to more than $500 million. In some areas of Chile, the impact of the tsunami wave was so strong that many houses were carried away 3 km inland.

7. Alaska

On March 27, 1964, the most powerful earthquake in American history occurred in Alaska. The magnitude of the earthquake was 9.2 on the Richter scale and this earthquake was the strongest since the disaster struck Chile in 1960.
129 people died, of which 6 were victims of tremors, the rest were washed away by a huge tsunami wave. The disaster caused the greatest destruction in Anchorage, and tremors were recorded in 47 US states.

6. Kobe

The Kobe earthquake in Japan on January 16, 1995 was one of the most destructive in history. Tremors with a magnitude of 7.3 began at 05:46 am local time and continued for several days. As a result, more than 6,000 people died and 26,000 were injured.

The damage caused to the city's infrastructure was simply enormous. More than 200,000 buildings were destroyed, 120 of the 150 berths in the port of Kobe were destroyed, and there was no power supply for several days. The total damage from the disaster was about $200 billion, which at that time was 2.5% of Japan's total GDP.

Not only government services rushed to help the affected residents, but also the Japanese mafia - the Yakuza, whose members delivered water and food to those affected by the disaster.

5. Sumatra

On December 26, 2004, a powerful tsunami that hit the shores of Thailand, Indonesia, Sri Lanka and other countries was caused by a devastating earthquake measuring 9.1 on the Richter scale. The epicenter of the tremors was in the Indian Ocean, near the island of Simeulue, off the northwestern coast of Sumatra. The earthquake was unusually large; the earth's crust shifted at a distance of 1200 km.

The height of the tsunami waves reached 15-30 meters and, according to various estimates, from 230 to 300,000 people became victims of the disaster, although the exact number of deaths is impossible to calculate. Many people were simply washed into the ocean.
One of the reasons for such a number of victims was the lack of an early warning system in the Indian Ocean, with which it was possible to inform the local population of the approaching tsunami.

4. Kashmir

On October 8, 2005, the worst earthquake to hit South Asia in a century occurred in the Pakistani-controlled region of Kashmir. The strength of the tremors was 7.6 on the Richter scale, which is comparable to the San Francisco earthquake in 1906.
As a result of the disaster, according to official data, 84,000 people died, according to unofficial data, more than 200,000. Rescue efforts have been hampered by military conflict between Pakistan and India in the region. Many villages were completely wiped off the face of the earth, and the city of Balakot in Pakistan was completely destroyed. In India, 1,300 people became victims of the earthquake.

3. Haiti

On January 12, 2010, an earthquake measuring 7.0 on the Richter scale occurred in Haiti. The main blow fell on the capital of the state - the city of Port-au-Prince. The consequences were terrible: almost 3 million people were left homeless, all hospitals and thousands of residential buildings were destroyed. The number of victims was simply enormous, according to various estimates from 160 to 230,000 people.

Criminals who had escaped from a prison destroyed by the elements poured into the city; cases of looting, robberies and robberies became frequent on the streets. Material damage from the earthquake is estimated at 5.6 billion dollars.

Despite the fact that many countries - Russia, France, Spain, Ukraine, the USA, Canada and dozens of others - provided all possible assistance in eliminating the consequences of the disaster in Haiti, more than five years after the earthquake, more than 80,000 people still live in improvised camps for refugees.
Haiti is the poorest country in the Western Hemisphere and this natural disaster has dealt an irreparable blow to the economy and living standards of its citizens.

2. Earthquake in Japan

On March 11, 2011, the strongest earthquake in Japanese history occurred in the Tohoku region. The epicenter was located east of the island of Honshu and the strength of the tremors was 9.1 on the Richter scale.
As a result of the disaster, the nuclear power plant in the city of Fukushima was severely damaged and power units at reactors 1, 2, and 3 were destroyed. Many areas became uninhabitable as a result of radioactive radiation.

After underwater tremors, a huge tsunami wave covered the coast and destroyed thousands of administrative and residential buildings. More than 16,000 people died, 2,500 are still considered missing.

The material damage was also colossal - more than $100 billion. And given that the complete restoration of the destroyed infrastructure may take years, the amount of damage may increase several times.

1. Spitak and Leninakan

There are many tragic dates in the history of the USSR, and one of the most famous is the earthquake that shook the Armenian SSR on December 7, 1988. Powerful tremors in just half a minute almost completely destroyed the northern part of the republic, capturing the territory where more than 1 million inhabitants lived.

The consequences of the disaster were monstrous: the city of Spitak was almost completely wiped off the face of the Earth, Leninakan was severely damaged, more than 300 villages were destroyed and 40% of the republic’s industrial capacity was destroyed. More than 500 thousand Armenians were left homeless, according to various estimates, from 25,000 to 170,000 residents died, 17,000 citizens remained disabled.
111 states and all republics of the USSR provided assistance in the restoration of destroyed Armenia.

One of the most terrible and unpredictable natural phenomena occurring on planet Earth is an earthquake. The destructive power of this earthly catastrophe can reach colossal proportions and humanity cannot fight it. Due to the fact that earthquakes or tremors occur as a result of sudden and fleeting changes in the very depths of the planet, it is currently almost impossible to prevent their occurrence. And sometimes it is also quite difficult to predict where, when and with what force tremors will occur. Therefore, in order to try to save yourself and the lives of your loved ones during this natural disaster, it is very important to know what to do during an earthquake and be able to provide first aid.

A huge number of earthquakes occur on planet Earth every year. But due to the fact that most of them have a very small impact force or occur at the very bottom of the oceans, many of the tremors do not affect us at all and we are absolutely unaware of their occurrence, and some are not even aware of their existence. Noticeable destruction can only be caused by strong earthquakes or tsunamis that arise in the ocean due to them.

Due to the fact that during earthquakes its energy is produced in many different forms (magnetic, electrical, mechanical), it is impossible to measure the force of its action with absolute accuracy. The greatest part of the destructive power of this natural phenomenon occurs at the epicenter of its occurrence, and the rest of the energy turns into waves, the strength of which decreases with increasing distance.

The strength of an earthquake is usually determined by such concepts as intensity, magnitude and energy class. The most accurate measurement of the amplitude of an earthquake is considered, that is, the magnitude of the vibrations that arise directly at the very epicenter of the disaster, and the concept of intensity or intensity, measured in points, is more often used in everyday life, since it is this that allows us to characterize the strength of the earthquake on the surface of the earth’s crust. The stronger the earthquake and the closer its epicenter, the greater the intensity. Let's consider the impact of this natural disaster depending on the number of points of its intensity:

• From 1 to 2 points– insignificant shock force, which can only be determined with the help of special instruments. Earthquakes of magnitude 2 can also sometimes be detected by a person if at that moment he is motionless.
• From 3 to 4 points– tremors are felt more strongly in high-rise buildings, chandeliers may sway, slight mixing of objects and a feeling of slight dizziness.
• From 5 to 7 points– the tremors begin to be felt quite strongly on the ground, minor destruction of buildings is possible, for example, cracks begin to appear on the walls, windows break, and plaster crumbles.
• 8 points– an earthquake causes deep cracks to appear on houses, the ground and even slopes.
• 9 points– the tremors become so strong that they can destroy the walls of houses and even some underground communication structures.
• From 10 to 11 points– an earthquake of such strength causes severe destruction of many buildings, bridges, collapses, and landslides.
• 12 points– the destructive force of such shocks can significantly change the surface of the earth’s crust, practically crumble buildings and even change the movement of water in rivers.

The strength of an earthquake largely depends on how close to the Earth's surface internal changes and movements of the earth's crust occurred. The closer the source, the greater the destructive power of a natural disaster.

Causes of earthquakes

Quite often, many people have the question: “Why do earthquakes happen?” In ancient times, people believed that such disasters were sent to them from above as punishment for bad deeds. Currently, despite the fact that this question has not yet been fully studied, scientists have some answers. In fact, there are quite a lot of reasons for the occurrence of such disasters and they are all divided into the following impacts:

• Natural. Natural influences include internal changes of the planet Earth, the influence of cosmic storms, the sun, and some other phenomena of the Cosmos.
• Artificial. The artificial influence on the motivation for the occurrence of an earthquake is Man and his influence on the environment. Such actions can be explosions, digging up earth rocks for mining, and the like.

Depending on the cause of occurrence, the following types of earthquakes are distinguished:

• Tectonic earthquakes. This type is the most common phenomenon that occurs due to movements, faults and collisions of tectonic plates. Such earthquakes manifest themselves in different ways. This may be the appearance of huge cracks on the surface of the earth, various collapses and landslides, or, with low strength, earthquakes may not reveal themselves at all.
• Landslide earthquakes. These earthquakes occur due to the impact of landslides and landslides on the earth's crust. Such phenomena most often occur due to the appearance of voids underground and inside the mountains. Most often, landslide earthquakes are not very powerful.
• Volcanic earthquakes caused by a volcanic eruption. Their peculiarity is that they do not cause any significant destruction and can be repeated a number of times.
• Artificial earthquakes. This type occurs as a result of a large number of simultaneous explosions, nuclear explosions, as well as underground tests of various types of weapons.
• Man-made earthquakes arise from direct human impact on the environment. It can arise as a result of artificial changes in the landscape during the construction of dams or new structures, the search for oil accumulations, the extraction of various types of minerals, or the destruction of mountains and plains by humans.

According to the results of numerous observations, the following natural phenomena occur before the occurrence of many earthquakes:

• Heavy and prolonged rain showers.
• The appearance in the air of an excess of gases such as uranium compounds, radon, helium, argon.
• Severe anxiety and unusual behavior of domestic and wild animals, it is believed that, for example.
• An unexpected glow in the air.

Ecological consequences of earthquakes

Depending on the strength of the earthquake, the proximity of the epicenter, and the location of its occurrence, varying degrees of consequences of this phenomenon appear.

Disasters with higher intensity significantly affect the ecology of the environment.

• The most common environmental consequences resulting from earthquakes are the occurrence of such natural processes as landslides, landslides, mudflows, destruction of the earth's crust and even floods. With any even slight change in the usual landscape, in any case, great stress arises for the living organisms living in this area. For example, large landslide debris spoils the composition of the soil; flooding caused by an earthquake tsunami can permanently kill the life of organisms in the area.
• In the case of deep faults, various heavy metals begin to enter the atmosphere from the bowels of the earth, negatively affecting living organisms.
• One of the most dangerous effects of an earthquake is the provocation of man-made disasters. In the event that it arose in an area where there were various structures created to create production technologies, such as, for example, an oil refinery or pharmaceutical enterprise. As a result of violations of such buildings, severe environmental pollution almost always occurs.
• If an earthquake occurs in an area where waste was stored, all toxic and unsafe substances can spread over a long distance around the area, which is also detrimental to good environmental conditions.
• The destruction of oil and gas pipes is also very dangerous, causing a large accumulation of harmful substances in the air.
• The destruction of such energy facilities as a result of an earthquake, such as thermal power plants and state regional power plants, can cause fires of enormous destructive proportions, capable of destroying the area for many kilometers around. The most terrible consequences of earthquakes occur when a nuclear power plant is destroyed.

The area where earthquakes occur does not have a uniform distribution. The main point or seismic belt where earthquakes often occur is in the Pacific Ocean. This belt covers Indonesia, the western coast of Central and South America, Japan, Iceland, Kamchatka, Hawaii, the Philippines, the Kuril Islands and Alaska.

The regions of the Eurasian belt are in second place in terms of seismic activity. It includes such mountain ranges as the Pyrenees, Caucasus, Tibet, Apennines, Himalayas, Altai, Pamir and Balkans.

A large number of earthquakes occur along fault lines and where plate collisions are most likely to occur, as well as in places where volcanoes are active.

Over the past ten years, the most destructive and powerful disasters have occurred in the following countries:

• India – more than 20 thousand victims.
• Iran - an entire city was razed to the ground and about 30 thousand people died.
• O. Sumatra - more than 200 thousand people became victims.
• Pakistan - more than 70 thousand dead.
• China – more than 80 thousand died
• Haiti – more than 200 thousand people became victims.
• Japan - the earthquake caused the death of about 30 thousand people and caused the destruction of nuclear power plants, which led to harmful emissions into the atmosphere.

Where do earthquakes occur in Russia?

Russia also has a fairly large number of places where earthquakes periodically occur. The main seismically active points here are mountainous areas such as Kamchatka, Eastern Siberia, the Caucasus, and Altai. Also, quite often, similar catastrophes of fairly large scale were noticed on Sakhalin and the Kuril Islands, where tsunamis are also often formed due to earthquakes.

The most destructive and terrible in terms of the scale of casualties and destruction in recent years in Russia was the earthquake that occurred on the island of Sakhalin in 1995. The intensity of this disaster was almost 8 points, which contributed to the destruction of most of the city of Neftegorsk, where it occurred, and the death of more than two thousand people.

It is very important for every person to know the rules of behavior during an earthquake in order not to get confused at the most crucial moment and to try, if possible, to provide themselves and others with the maximum possible help. First of all, this applies to those people who permanently live or are temporarily located in seismically dangerous zones, who must always be prepared.

In order for an earthquake not to take all important documents and savings by surprise, a first aid kit, as well as a flashlight, must be stored in one place, and always keep in mind an approximate plan of action when you are in any of the possible places where you could be. Also, do not store heavy, sharp or nuclear-containing substances on top shelves and cabinets.

If you receive a message about a strong earthquake and the need to evacuate, if you are not at home and you have a small amount of time, you need to immediately go to your home, collect all the necessary documents and things, turn off the water, electricity and gas and close the doors. After which it is necessary to leave the populated area as soon as possible and go to a safer place.

During an earthquake, it is very important to pull yourself together, suppress panic and confusion, and try to act rationally, as quickly and productively as possible, in order to have a greater chance of saving yourself from damage. First of all, if you are indoors, you should try to get out of the premises as soon as possible, while capturing and, if possible, going to a more open area where there is no electricity, buildings or trees nearby. If you exit from higher floors, it is better to do so by stairs rather than by elevator.

If you cannot leave the premises, you must find the safest place in it. This could be a place near a load-bearing wall that is not overloaded with objects, a doorway, or under a strong table or bed that will be able to protect from falling objects. Under no circumstances should you stand near windows, shelves or heavy objects; you should also not use gas or electricity.

If there are children near you, first of all you need to try to calm them down, find them a secluded place, or, if you are in an open area, under no circumstances let them out of sight and keep them close to you.

If an earthquake finds you in a car, you also need to try to find a more open area, not cluttered with poles, various plantings and billboards intended for advertising, stop the car, open the door and stay in it until the tremors are over.

They demonstrated the terrifying power of these natural phenomena. Almost 16,000 people died and more than a million buildings were completely or partially destroyed. A year after these events, 330,000 people are still living in hotels or other temporary housing, unable to return home. Another 3,000 people are still missing. Giant tsunami waves generated by the earthquake flooded the power and cooling systems of three reactors at the Fukushima nuclear power plant.

Earthquakes cannot be stopped, but we know how they work. Scientists have developed networks of sensors to monitor the movement of the earth, changes in groundwater and magnetic fields that can indicate an impending earthquake. Engineers, meanwhile, have developed new forms of architecture to withstand earthquakes. So, without further ado, let's find out the most interesting facts about earthquakes.

1. The record depth at which the earthquake epicenter was recorded.

750 kilometers.

2. How many earthquakes occur per year?

3. Do earthquakes occur more often in warm weather?

4. What is the earth's crust made of?

The Earth's crust is broken into moving pieces called plates. These plates float on the dense rocks of the mantle, a sticky layer that lies between the planet's core and the Earth's crust. The most common rock in the crust that forms the Earth's continents is granite. This continental crust averages 35 km thick and is deepest beneath mountain ranges. The oceanic crust is thinner - six kilometers on average - and is mostly made of dense volcanic rocks such as basalt. Interestingly, granite consists of 75% oxygen and silicon. Basalt is denser because the silicon is contaminated with heavy elements such as iron.

5. How thick is the earth's crust?

from 5 to 70 kilometers.

6. Did the earthquake in Japan in 2011 really make the days shorter?

Yes, but you'll hardly notice it. Every day is now 1.8 microseconds shorter, according to NASA. The fact is that the Japanese earthquake accelerated the rotation of the Earth, changing its rotation around an imaginary line called an axis. The Earth's mass is balanced around its axis, and it wobbles as it rotates. This fluctuation is up to one meter per year due to the movement of glaciers and ocean currents. In 2011, an earthquake moved the ocean floor near Japan as much as 16 meters vertically and 50 meters horizontally—equivalent to the horizontal distance of an Olympic swimming pool! Shifts of the ocean floor increased the Earth's oscillations around its axis by 17 centimeters. And as the vibrations increased, the Earth accelerated its rotation. This principle will be better understood if we remember that a skater pulls his arms closer to his body in order to spin faster.

7. What is the shadow side of an earthquake?

The shadow zone is where seismographs cannot detect an earthquake after its seismic waves have passed through the Earth. The shadow zone is located on the Earth's surface at an angle of 104-140 degrees from the origin of the earthquake, and is not crossed by S-waves or direct P-waves. The shadow zone forms because S-waves cannot pass through the Earth's liquid outer core, while P-waves are refracted by the liquid core.

8. Where do earthquakes most often occur?

About 90 percent of earthquakes occur on the so-called Ring of Fire, a belt of seismic activity surrounding the Pacific Plate. The Ring of Fire is a massive subduction zone where the Pacific Plate collides with and sinks beneath other crustal plates. Most earthquakes have been observed in Japan, which lies on the Ring of Fire at the junction of the Pacific, Philippine, Eurasian and Okhotsk plates. Japan has a good earthquake monitoring network, and scientists can detect even small earthquakes. Indonesia's volcanic island chain probably experiences the highest number of earthquakes on land, but has fewer instruments to measure them.

9. Is it true that earthquakes occur more often in the morning?

10. What are tremors?

Tremors are another name for earthquakes. It also represents the vibration you experience during an earthquake.

11. How do scientists record the size of an earthquake?

Scientists use a seismograph to record earthquake waves called P and S waves. P waves travel faster than S waves and can travel through liquids. By measuring the delay between the P and S waves, scientists can calculate the distance the waves have traveled.

12. When was the earliest record of a major earthquake in history?

The first earthquake was described in China in 1177 BC. By the 17th century, accounts of the effects of earthquakes were published around the world.

13. What do the lines on a seismograph mean?

The wavy lines on the seismogram represent the recorded waves. The first large wavy line is P-waves, the second line is S-waves. If the latter is missing, the earthquake occurred on the other side of the planet.

14. Why do earthquakes cause tsunamis?

When two plates come into contact underwater, they exert pressure on each other, thereby creating pressure. There comes a time when one slab cannot stand it and slides off. As a result, the accumulated energy is released and an underwater earthquake occurs. A column of water is pushed upward, resulting in a tsunami on the surface of the ocean. Tsunamis are giant waves that can cross oceans at enormous speeds of up to 700 kilometers per hour and reach heights of 20 meters.

15. How do P and S waves move?

P waves (primary waves) are the fastest waves produced by an earthquake. They can pass through solid and molten rocks. P waves move in a spiral that resembles a Slinky spring toy.

S-waves (secondary waves) are 1.7 times slower than P-waves and can only travel through hard rock. However, they cause more damage because they are larger and shake the ground vertically and horizontally.

16. How long do earthquakes last?

10-30 seconds.

17. Do earthquakes occur only on Earth?

There is evidence of "marsquakes" on Mars, as well as "Venusquakes" on Venus. Signs of earthquakes have also been observed on several of Jupiter's moons, as well as on one of Saturn's moons. In addition, tidal “moonquakes” have been discovered on the Moon, which are caused by the influence of Earth’s gravity. The moon also vibrates from meteorite impacts and tremors caused by the heating of the lunar surface after a two-week lunar night.

18. Can animals predict earthquakes?

It is not known for certain whether animals can predict earthquakes, but there are many stories about their strange behavior. One such story claims that hibernating snakes left their burrows a month before the earthquake that struck China in 1975.

Earthquakes are a natural phenomenon that even today attracts the attention of scientists not only due to their lack of knowledge, but also due to their unpredictability, which can harm humanity.

What is an earthquake?

An earthquake is an underground tremors that can be felt by a person largely depending on the power of vibration of the earth's surface. Earthquakes are not uncommon and occur every day in different parts of the planet. Often, most earthquakes occur at the bottom of the oceans, which avoids catastrophic destruction within densely populated cities.

The principle of earthquakes

What causes earthquakes? Earthquakes can be caused by both natural causes and man-made ones.

Most often, earthquakes occur due to faults in tectonic plates and their rapid displacement. For a person, a fault is not noticeable until the moment when the energy generated from the rupture of rocks begins to break out to the surface.

How do earthquakes occur due to unnatural causes? Quite often, a person, through his carelessness, provokes the appearance of artificial tremors, which in their power are not at all inferior to natural ones. Among these reasons are the following:

• - explosions;
• - overfilling of reservoirs;
• - above-ground (underground) nuclear explosion;
• - collapses in mines.

The location where a tectonic plate breaks is the source of an earthquake. Not only the strength of the potential push, but also its duration will depend on the depth of its location. If the source is located 100 kilometers from the surface, then its strength will be more than noticeable. Most likely, this earthquake will lead to the destruction of houses and buildings. Occurring in the sea, such earthquakes cause tsunamis. However, the source can be located much deeper - 700 and 800 kilometers. Such phenomena are not dangerous and can only be recorded using special instruments - seismographs.

The place where the earthquake is most powerful is called the epicenter. It is this piece of land that is considered the most dangerous for the existence of all living things.

Studying earthquakes

A detailed study of the nature of earthquakes makes it possible to prevent many of them and make the life of the population living in dangerous places more peaceful. To determine the power and measure the strength of an earthquake, two basic concepts are used:

• - magnitude;
• - intensity;

The magnitude of an earthquake is a measure that measures the energy released during release from the source in the form of seismic waves. The magnitude scale allows you to accurately determine the origins of vibrations.

Intensity is measured in points and allows you to determine the ratio of the magnitude of tremors and their seismic activity from 0 to 12 points on the Richter scale.

Features and signs of earthquakes

Regardless of what causes an earthquake and in what area it is localized, its duration will be approximately the same. One push lasts on average 20-30 seconds. But history has recorded cases when a single shock without repetitions could last up to three minutes.

Signs of an approaching earthquake are the anxiety of animals, which, sensing the slightest vibrations on the surface of the earth, try to get away from the ill-fated place. Other signs of an imminent earthquake include:

• - the appearance of characteristic clouds in the form of oblong ribbons;
• - change in water level in wells;
• - malfunctions of electrical equipment and mobile phones.

How to behave during earthquakes?

How to behave during an earthquake to save your life?

• - Maintain reasonableness and calm;
• - When indoors, never hide under fragile furniture, such as a bed. Lie down next to them in the fetal position and cover your head with your hands (or protect your head with something extra). If the roof collapses, it will fall on the furniture and a layer may form, in which you will find yourself. It is important to choose strong furniture whose widest part is on the floor, i.e. this furniture cannot fall;
• - When outside, move away from tall buildings and structures, power lines that may collapse.
• - Cover your mouth and nose with a wet cloth to prevent dust and fumes from entering if any object catches fire.

If you notice an injured person in a building, wait until the tremors are over and only then get into the room. Otherwise, both people may be trapped.

Where do earthquakes not occur and why?

Earthquakes occur where tectonic plates break. Therefore, countries and cities located on a solid tectonic plate without faults do not have to worry about their safety.

Australia is the only continent in the world that is not at the junction of lithospheric plates. There are no active volcanoes and high mountains on it and, accordingly, there are no earthquakes. There are also no earthquakes in Antarctica and Greenland. The presence of the enormous weight of the ice shell prevents the spread of tremors across the surface of the earth.

The probability of earthquakes occurring on the territory of the Russian Federation is quite high in rocky areas, where the displacement and movement of rocks is most actively observed. Thus, high seismicity is observed in the North Caucasus, Altai, Siberia and the Far East.