Table of Contents
- 1 10 causes of Earthquakes in the World
- 2 Types of Earthquakes
- 3 Epicentre and Focus of Earthquakes
- 4 What Are Seismic Waves?
- 4.1 Types of Seismic Waves
- 4.2 How Are Earthquakes Measured?
- 5 Foreshocks and Aftershocks
- 5.1 When and Where Do Earthquakes Occur?
- 5.2 Can Earthquakes Be Predicted?
- 5.3 Earthquakes Effects
- 5.4 How to Stay Safe If an Earthquake Strikes?
- 5.5 10 of the Largest Earthquakes by Magnitude in History
- 5.5.1 1. Valdivia Earthquake (22 May 1960) – 9.4-9.6
- 5.5.2 2. Great Alaska Earthquake (27 March 1964) – 9.2
- 5.5.3 3. Sumatra Earthquake (2004) – 9.1-9.3
- 5.5.4 4. Tōhoku earthquake (2011) – 9.1
- 5.5.5 5. Kamchatka, Russia Earthquake (1952) – 9.0
- 5.5.6 6. Chile Earthquake (2010) – 8.8
- 5.5.7 7. Ecuador-Colombia Earthquake (1906) – 8.8
- 5.5.8 8. Rat Islands Earthquake (1965) – 8.7
- 5.5.9 9. Assam-Tibet Earthquake (1950) – 8.6
- 5.5.10 10. Sumatra Earthquake (2012) – 8.6
- 5.6 10 of the Deadliest Earthquakes in History
- 5.6.1 1. Shaanxi Earthquake, 1556
- 5.6.2 2. Antioch Earthquake, 115
- 5.6.3 3. Antioch Earthquake, 526
- 5.6.4 4. Tangshan Earthquake, 1976
- 5.6.5 5. Haiyuan Earthquake, 1920
- 5.6.6 6. Aleppo Earthquake, 1138
- 5.6.7 7. Sumatra Earthquake 2004
- 5.6.8 8. Haiti Earthquake, 2010
- 5.6.9 9. Great Kantō Earthquake, 1932
- 5.6.10 10. Ashgabat Earthquake, 1948
- 5.7 Quick Facts
- 5.8 Frequently Asked Questions
10 causes of Earthquakes in the World
What Is an Earthquake?
Earthquakes, the formidable natural phenomena that can shake the very foundations of our planet, have captivated human curiosity for centuries. Understanding the causes of earthquakes (seismic events) is crucial for scientists, engineers, and the general public alike. An earthquake is a shaking, rolling, or sudden shock of the surface of the Earth.
An earthquake, also known as a seismic event, is a powerful shaking, rumbling, or sudden jolt beneath Earth’s surface. Picture yourself standing on a massive rug, and someone unexpectedly yanks it out from under you! That’s what experiencing an earthquake can feel like.
Scientists who study earthquakes are called seismologists. They use special instruments called seismometers to measure and study the waves produced by earthquakes. This helps them understand the causes of earthquakes, and they can even predict some earthquakes by studying patterns and monitoring the movements of the tectonic plates.
You might be pondering, “What exactly are tectonic plates?” Excellent question!
Tectonic plates are gigantic, jigsaw-like slabs that form Earth’s outer layer or lithosphere. These plates are continuously on the move, albeit at a pace too slow for us to notice. However, when they do shift, they generate an immense amount of energy that travels through the Earth as seismic waves, resulting in an earthquake. They are the major causes of earthquakes.
Earthquakes can happen in different places around the world. Some areas are more prone to earthquakes because they are located near the edges of these tectonic plates, where a lot of plate movements occur. For example, the Pacific Rim, also known as the ‘Ring of Fire,’ is an area where many earthquakes happen because several tectonic plates meet there.
What are the Causes of Earthquakes?
You see, the Earth is like a big ball made up of different pieces called tectonic plates. These plates are like giant puzzle pieces that fit together. Sometimes, these puzzle pieces move around, and when they rub against each other or push each other, they can cause the ground to shake. It’s like when you push two toy cars together, and they bump into each other.
When the plates slip, it sends waves of energy called seismic waves throughout the Earth. These waves make the ground shake, and that’s why you feel the earthquake. Depending on how big and strong the earthquake is, the shaking can be gentle, like a little wobble, or it can be really powerful, causing things to fall and buildings to sway.
The plates are always moving and pushing into each other, but they move slowly. Sometimes the plates slide under or against each other and become stuck. When they slide apart, they create pressure force. When the force becomes too great, the rock masses suddenly shift causing a fault in the crust. A fault is a crack in the Earth’s crust. This force causes the Earth to shake and ripple, and this is how we get an earthquake.
Sometimes earthquakes occur because of other natural or human causes. For example, the movement of magma beneath a volcano can cause an earthquake. Holding great amounts of water behind dams causes pressure which can cause quakes. Furthermore, the digging of mines and underground nuclear explosions can also cause quakes.
Types of Faults Resulting Causes of Earthquakes
Did you know that earthquakes can happen because of something called faults? Faults are like big cracks in the Earth’s crust where the rocks can move. Let’s explore the different types of faults that can cause earthquakes.
There are three main types of geological fault that may contribute to causes of earthquakes: normal, reverse, and strike-slip. Normal faults occur when the crust is extended. Reverse faults occur when the crust is shortened. Strike-slip faults occur when the two sides of the fault slip horizontally past each other.
1. Normal Faults
Imagine you have a piece of paper, and you pull both ends of it in opposite directions. What happens? The paper bends, and one side moves up while the other side moves down. Well, that’s similar to a normal fault. When the Earth’s crust is stretched or pulled apart, it creates a normal fault. The rocks on one side move down, and the rocks on the other side move up. This is one of the causes of earthquakes.
2. Reverse Faults:
Now, picture that you push both ends of the paper together, making a little hill or ridge in the middle. That’s similar to a reverse fault. When the Earth’s crust is being squeezed together, it creates a reverse fault. The rocks on one side move up, and the rocks on the other side move down. This squeezing and movement of rocks is also one of the causes of earthquakes.
3. Strike-Slip Faults:
Here’s a different type of fault. Imagine you have two pieces of paper, and you slide one piece past the other horizontally. That’s similar to a strike-slip fault. When the rocks on both sides of the fault move sideways past each other, it creates a strike-slip fault. This sideways sliding can generate strong earthquakes too. This is one of the causes of earthquakes.
Types of Earthquakes
Did you know that not all earthquakes are the same? That’s right! There are various types of earthquakes, each with its own unique characteristics and causes. Let’s check out these fascinating ground-shaking events and how they differ from one another.
1. Tectonic Earthquakes
The most common type of earthquake is called a tectonic earthquake. These earthquakes happen when the Earth’s tectonic plates, which are like giant puzzle pieces that make up the Earth’s crust, move and slide past each other. When the plates get stuck and can’t move smoothly, they build up pressure. When the pressure becomes too much, the plates suddenly slip, causing the ground to shake. Tectonic earthquakes can be big or small, depending on how much pressure is released. The intense energy released during these movements results in the ground shaking and trembling that we know as an earthquake.
2. Volcanic Earthquakes
Another type of earthquake is linked to volcanic activity. When a volcano erupts, the molten rock beneath the Earth’s surface, called magma, rises to the top. As the magma moves and pushes its way out, it can cause the ground to shake. These earthquakes are called volcanic earthquakes. They often happen near volcanoes and can be a sign that the volcano is becoming more active.
When molten rock, or magma, moves beneath the Earth’s surface, it can create pressure and cause the surrounding rocks to fracture. This movement, along with the shifting tectonic plates, can trigger these unique ground-shaking events.
3. Collapse Earthquakes
Collapse earthquakes are smaller earthquakes that take place in underground spaces such as caverns and mines. These quakes happen when the ground above these hollow areas collapses or caves in. Although collapse earthquakes are usually less powerful than other types of earthquakes, they can still cause significant damage if the collapsed cavities are located beneath buildings or other structures.
4. Explosive Earthquakes
Believe it or not, humans can sometimes cause earthquakes too! Certain human activities, like mining deep underground or injecting fluids into the ground, can change the pressure and stress on rocks. This alteration can trigger earthquakes. These earthquakes are called human-induced causes of earthquakes.
Explosive earthquakes are man-made events that occur as a result of the detonation of nuclear or chemical devices or weapons. These explosions release a tremendous amount of energy, causing the ground to shake and create earthquake-like effects. Unlike the other types and causes of earthquakes, explosive earthquakes are not caused by natural processes.
Usually, they are not very strong and not dangerous, but scientists are studying them to understand how to minimize any risks.
Epicentre and Focus of Earthquakes
The epicenter of an earthquake is a crucial point on Earth’s surface that lies directly above the location where the rocks cracked or shifted deep within the Earth. This spot helps scientists understand where the earthquake originated and which areas might have experienced the strongest shaking.
Meanwhile, the focus of an earthquake, also known as the hypocenter, is the actual site where the rocks cracked or slipped underground. The focus is often situated miles beneath Earth’s surface, hidden from view but responsible for the tremors we feel above ground. When an earthquake occurs, seismic waves radiate outwards from the focus, traveling through the Earth and causing the ground to shake and vibrate.
Understanding the difference between the epicenter and focus is essential for grasping the mechanics of earthquakes. The focus represents the underground source of the earthquake, while the epicenter is the point on the surface directly above it. By studying these two key components, scientists can gain valuable insights into the causes, locations, and impacts of these awe-inspiring natural phenomena.
What Are Seismic Waves?
Have you ever wondered how the energy from an earthquake travels through the Earth? Well, it’s because of something called seismic waves! Let’s explore what seismic waves are and how they work.
Seismic waves are like ripples or vibrations that spread out from the source of an earthquake. Imagine dropping a pebble into a calm pond. When the pebble hits the water, it creates ripples that spread out in all directions. Those ripples are a lot like seismic waves, but instead of water, they travel through the Earth! They are most powerful at the center of the earthquake, but they travel through much of the Earth and back to the surface. They move quickly at 20 times the speed of sound.
Types of Seismic Waves
There are two basic types of seismic waves: Body Waves and Surface Waves.
1. Body Waves
They are the waves that travel through the Earth. They are classified into two types:
a. Primary Waves (P-Waves)
The first waves of an earthquake. They cause the ground to move back and forth in the direction of travel. P-waves are the fastest seismic waves and the first ones to reach us during an earthquake. They are also the first waves to arrive at seismic recording stations. They are like a “push and pull” motion. Imagine pushing and pulling a slinky toy back and forth. That’s how P-waves move! They can travel through solids, liquids, and gases, so they can move through the Earth’s layers.
b. Secondary Waves (S-Waves)
The next waves to arrive. They are also called transverse waves. They move more slowly than P-waves. S-waves are like a “shake” or a “wiggle” motion. Picture holding a rope and shaking it up and down. That’s how S-waves move! Unlike P-waves, they can only travel through solids, so they cannot pass through liquids like water or the Earth’s outer core. They travel slower through the Earth. This causes of earthquake waves cause the most damage.
2. Surface Waves
They are the waves that travel at the Earth’s surface. They are usually generated when the source of the earthquake is close to the Earth’s surface. Although the surface waves travel slower than the body waves, they are much larger and more destructive. There are two kinds of Surface Waves:
a. Rayleigh Waves
Also called ground roll. They cause the ground to shake in an elliptical pattern. This motion is similar to that in ocean waves.
b. Love Waves
They cause the surface to move horizontally from side to side perpendicular to the direction of travel. They move faster than Rayleigh waves.
How Are Earthquakes Measured?
Earthquakes occur very frequently though you might not always feel the shaking. This is because not all earthquakes are strong. But how are they measured? Earthquakes are measured according to two aspects: their magnitude and their intensity.
The magnitude of an earthquake is a measure of how large the earthquake is. It only measures the size and does not change depending on where you are or how the shaking feels. Earthquakes spread energy in the form of seismic waves. Instruments called seismographs are used to measure how large the earthquake was.
Earlier, the instrument was using a weighted pen and a spring, and the vibrations from the earthquake made the pen draw lines on some paper. A short wiggly line that didn’t wiggle very much meant a small earthquake, while a long wiggly line that wiggled a lot meant a large earthquake.
Then, from 1930 to 1970, scientists used the Richter scale to measure earthquakes. This scale, invented in 1934 by California scientist Charles Richter, measures the magnitude of an earthquake, and the result is a number from 0 to 10. The larger the number on the scale, the larger the earthquake. You usually won’t even notice an earthquake unless it measures at least a 3 on the scale.
However, the Richter scale only measures the largest wiggle of an earthquake. So, it was replaced with the Moment Magnitude Scale, which measures different parts of the earthquake and records all the different seismic waves to seismographs across the world.
Earthquake Magnitude Classes
Earthquakes are classified into classes depending on their magnitude. These classes also provide earthquake measurement. The classification starts with “minor” for lower magnitudes and ends with “great” for the largest magnitudes. The classes are:
|Description and Damage
|3.0 – 3.9
|May be felt.
|4.0 – 4.9
|Could shake your house. Some people may not notice.
|5.0 – 5.9
|Stuff may fall off of shelves. There may be minor damage.
|6.0 – 6.9
|May cause damage to buildings and other structures. Walls in some houses may crack and windows break.
|7.0 – 7.9
|Serious damage. Weaker buildings will collapse, and cracks will occur in bridges and on the street.
|8.0 – 8.9
|There will be significant damage. Large cracks will appear in the Earth. Sometimes whole cities could be flattened.
The intensity of an earthquake is a measure of how much damage it caused. It tells the severity of the shaking and its effects on people and their environment. So, intensity measurements differ from one location to another depending on how near it is to the epicentre. This means that there can be multiple intensity measurements as opposed to one magnitude measurement.
Earthquake Intensity Scale
Scientists use the Modified Mercalli Scale to measure the intensity of an earthquake. The scale is composed of 12 levels that range from observable quake impacts to catastrophic destruction. Intensity is reported by Roman numerals.
|Description and Damage
|Light shaking. Most people feel it indoors, and some may feel it outdoors. There are vibrations. Windows, dishes, and doors rattle. Walls may make cracking sounds.
|Weak shaking. Only a few people may feel it, especially on upper floors or buildings. Hanging objects may swing gently.
|Weak shaking. People can feel it indoors, especially on upper floors or buildings. Many people do not recognize it as an earthquake. Vibrations are similar to the passing of a truck.
|Moderate shaking. Almost everyone feels it. It wakes sleeping people up. Liquids may be spilled. Doors swing. Windows and dishes are broken. Pendulum clocks may stop or change the rate.
|Very strong shaking. It is difficult to stand. Weak buildings are damaged. Loose bricks, stones and tiles fall. Some chimneys are broken. The furniture is broken.
|Strong shaking. Everyone feels it. It is frightening. People walk unsteadily. Trees shake. Pictures fall off walls. Furniture moves or overturns.
|Severe shaking. Many buildings are damaged, and some may collapse. Chimneys, columns, monuments, and walls fall. Tree branches are broken. There may be cracks in wet ground and on steep slopes.
|Violent shaking. Even strong buildings are damaged. Some buildings completely collapse, and some shift off foundations. There are cracks in the ground. Underground pipes get broken.
|Extreme shaking. There are large landslides. Most buildings are destroyed with their foundations. Bridges, dams, and dikes are destroyed. Water gets thrown on banks of canals, rivers and lakes. Railway rails bent slightly.
|Extreme shaking. There are large landslides. Most buildings are destroyed with their foundations. Bridges, dams, and dikes are destroyed. Water gets thrown on banks of canals, rivers, and lakes. Railway rails bent slightly.
|Railway rails bent greatly. Underground pipes are completely destroyed.
|Nearly total damage. Objects are thrown into the air. Large rock masses get displaced. Whole cities may be flattened.
Foreshocks and Aftershocks
Foreshocks are smaller earthquakes that take place before the main earthquake, or mainshock occurs. These preliminary tremors can sometimes provide scientists with clues about an impending larger seismic event. However, predicting the exact timing and magnitude of a mainshock based on foreshocks remains a challenge for seismologists.
The mainshock is the largest and most powerful earthquake in a series of seismic events. This primary tremor is the one that typically causes the most damage and receives the most attention from scientists, emergency responders, and the public.
Aftershocks are the smaller earthquakes that follow the mainshock. These subsequent tremors can continue for hours, days, or even months after the main earthquake. Aftershocks are typically less powerful than the mainshock but can still cause additional damage to weakened structures and pose risks to people in affected areas.
By understanding the differences between foreshocks, mainshocks, and aftershocks, we can better appreciate the complex and dynamic nature of earthquake sequences.
When and Where Do Earthquakes Occur?
Earthquakes can happen anywhere. Most of them occur along the edges of the plates of Earth’s crust. One great earthquake belt is known as the “Ring of Fire”. This is an area around the edges of the Pacific Ocean. Most large earthquakes occur in the Ring of Fire. Another belt is in the Mediterranean region between Europe and North Africa. In addition, earthquakes can occur at any time of the year and at any time of the day or night.
Can Earthquakes Be Predicted?
Unfortunately, earthquakes cannot be predicted. However, many large earthquakes have foreshocks that tell a large earthquake is coming. In addition, scientists have observed some physical changes that happen before some earthquakes in the environment around their epicentres. These changes include deformation in the crust in the fault zones and an increase in the volume of rocks. With continuous research, scientists may one day be able to predict earthquakes.
Earthquakes can do severe damage to buildings, bridges, pipelines, railways, dams, and other structures, and they can lead to deadly fires. Earthquakes can also cause serious changes at Earth’s surface. These changes include changes in the flow of groundwater, landslides, and mudflows.
Adding to all this, some quakes that occur underwater or near oceans can cause huge, deadly waves called tsunamis. The violent shaking of the seafloor produces waves that spread over the ocean’s surface. When these waves reach the shore, they destroy and wipe out the coastal regions.
How to Stay Safe If an Earthquake Strikes?
Earthquakes can be very dangerous, and they are unpredictable. So, it is important to know some simple safety rules to follow in case of an earthquake.
Preparing Before an Earthquake
- Make an emergency plan with your family members, and plan where to meet if you get separated.
- Know where your electricity, gas, and water switches are and how to shut them off.
- Store large, heavy, and breakable objects on low shelves.
- Practice how to “Drop, Cover, and Hold On” with each member of your household.
What to Do During an Earthquake?
- Drop, Cover, and Hold On: DROP down to the ground, COVER your head and neck with your arms, and HOLD ON to any sturdy item you can until the shaking stops.
- If you cannot drop to the ground, try to sit so the earthquake doesn’t knock you down.
- Crawl under a sturdy piece of furniture, if you can, for more protection.
- Stay away from glass, windows, outside doors and walls, and other items that could fall.
- If you are in bed, turn face down and cover your head and neck with a pillow.
- If you are outdoors, stay outdoors away from buildings. Do not try to run inside.
- If you are inside, stay and do not run outside or to other rooms.
- If you are in a car, stay in it and set the parking brake until the shaking stops.
After an Earthquake
- Earthquakes are sometimes followed by aftershocks. So, be ready to Drop, Cover, and Hold Onagain if you feel an aftershock. Aftershocks can go on for weeks or even months.
- Check your home for damage, and get everyone out if the building is unsafe.
- Do not enter any damaged buildings.
- If you are in a damaged building, go outside and quickly move away from the building.
- If you are trapped, try calling or texting for help. Bang on a pipe or use a whistle to help others know where you are. Cover your mouth with your shirt.
- If you are in an area that may experience tsunamis, go inland or to higher ground right after the shaking stops.
- Follow instructions from public safety officials.
10 of the Largest Earthquakes by Magnitude in History
1. Valdivia Earthquake (22 May 1960) – 9.4-9.6
It is the most powerful earthquake ever recorded. It struck in Chile, and it lasted for about 10 minutes. Not only that, but the earthquake also caused tsunami waves that affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand, southeast Australia, and the Aleutian Islands. Estimates said that between 1000 – 6000 people were killed.
2. Great Alaska Earthquake (27 March 1964) – 9.2
It is the most powerful earthquake in U.S. history. The earthquake lasted for about 4.5 minutes, and it caused a large tsunami and a massive underwater landslide. 139 people were killed: 15 as a result of the earthquake itself, 106 from the subsequent tsunami in Alaska, 5 from the tsunami in Oregon, and 13 from the tsunami in California.
3. Sumatra Earthquake (2004) – 9.1-9.3
Also known as the Indian Ocean Earthquake. Its epicentre was off the west coast of northern Sumatra, Indonesia. It was an undersea earthquake that lasted between eight and ten minutes, and it caused the whole planet to vibrate. The earthquake reached a Mercalli intensity of up to IX in some areas. This earthquake caused massive tsunami waves that killed at least 225,000 people across a dozen countries.
4. Tōhoku earthquake (2011) – 9.1
Also known as the Japan Earthquake. It was a massive undersea earthquake that occurred off the coast of Japan. The earthquake caused massive tsunami waves that were up to 40.5 metres (133 feet) high. It was one of the deadliest in human history. This resulted in 15,894 deaths, 6,152 injured, and 2,562 people went missing.
5. Kamchatka, Russia Earthquake (1952) – 9.0
It was a huge earthquake that struck off the coast of Kamchatka Peninsula, in the far east of Russia. The earthquake caused huge tsunami waves that went up to up to 15 metres (50 feet) high. It caused huge damage to the Kamchatka Peninsula and the Kuril Islands. Around 10,000 to 15,000 people were killed.
6. Chile Earthquake (2010) – 8.8
It occurred off the coast of central Chile, and lasted for about three minutes. The shaking caused some buildings to collapse in many cities, including the capital, Santiago. The earthquake also caused a tsunami that destroyed several coastal towns in Chile. Around 525 people were killed.
7. Ecuador-Colombia Earthquake (1906) – 8.8
It occurred off the coast of Ecuador, near Esmeraldas (a coastal city in northwestern Ecuador). The earthquake caused a destructive tsunami that killed at least 500 people on the coast of Colombia.
8. Rat Islands Earthquake (1965) – 8.7
This earthquake triggered a tsunami of over 10 metres on Shemya Island. However, it caused very little damage because of its distant location.
9. Assam-Tibet Earthquake (1950) – 8.6
This earthquake occurred at the Xizang-India border region. Many buildings were destroyed, and between 1.500 and 3.000 people were killed. The earthquake also caused large landslides that blocked the Subansiri River. This caused a huge wave to break out after some days that overflowed many villages and killed around 530 people.
10. Sumatra Earthquake (2012) – 8.6
It was an undersea earthquake in the Indian Ocean near the city of Aceh, Indonesia. Right after the shaking, authorities feared that the earthquake would cause a tsunami, and they issued warnings, but these warnings were then canceled. The earthquake occurred very far from any inhabited place, and it caused a small tsunami that was not destructive. There were around 10 deaths, most of them caused by panic or heart attacks.
10 of the Deadliest Earthquakes in History
1. Shaanxi Earthquake, 1556
The deadliest earthquake ever recorded in human history. It was a massive earthquake at magnitude 8 in Shaanxi province in northern China. The pre-modern buildings and structures were unable to withstand such a powerful earthquake. There were also great landslides because of the quake. This earthquake resulted in killing or injuring around 830,000 people.
2. Antioch Earthquake, 115
The most damaging earthquake in Turkey. It had a magnitude of 7.5 and a maximum intensity of XI (Extreme) on the Mercalli intensity scale. It destroyed over two-thirds of Antioch, and the damage extended to surrounding areas. It also caused a tsunami that damaged the coast of Lebanon. The total number of deaths is around 260,000 people.
3. Antioch Earthquake, 526
It struck Syria and the city of Antioch in the Byzantine Empire, with a magnitude of 7.0. The earthquake caused severe damage to many of the buildings in Antioch, but most of the damage was by the fires that broke out after the earthquake. More than 250,000 people died in this earthquake.
4. Tangshan Earthquake, 1976
With a magnitude of 7.5, this earthquake nearly destroyed the city of Tangshan, located east of Beijing. There was an aftershock that struck 16 hours later with a similar magnitude, and it was equally destroying. The reports said that around 240,000 people were killed and at least 700,000 people were injured.
5. Haiyuan Earthquake, 1920
It occurred in Haiyuan County, Ningxia Province, China, with a magnitude of 7.8 on the Richter scale. This earthquake caused rivers to change course and caused great landslides. It destroyed at least seven Chinese provinces, and a town was completely buried under a landslide. Around 230,000 people were killed.
6. Aleppo Earthquake, 1138
It struck Aleppo, a city in northern Syria. There was a small foreshock that made many people flee to the countryside before the main earthquake. On the next day, the mainshock occurred, and it caused severe damage. Many buildings collapsed, including the city walls. It is said that around 230,000 people were killed.
7. Sumatra Earthquake 2004
Also known as the Indian Ocean Earthquake. Its epicentre was off the west coast of northern Sumatra, Indonesia. It was an undersea earthquake that lasted between eight and ten minutes, and it caused the whole planet to vibrate. The earthquake reached a Mercalli intensity up to IX in some areas. This earthquake caused massive tsunami waves that killed at least 227,000 people across many countries.
8. Haiti Earthquake, 2010
With a magnitude of 7.0, this earthquake occurred on the West Indian Island of Hispaniola, comprising the countries of Haiti and the Dominican Republic. The earthquake was followed by more than 50 aftershocks. It caused extreme damage, and most buildings collapsed. Around 200,000 people were killed.
9. Great Kantō Earthquake, 1932
It was an earthquake with a magnitude of 7.9 that struck the Tokyo-Yokohama metropolitan area in Japan. It lasted between four and ten minutes. More than half of the brick buildings collapsed. Many hundreds of thousands of houses were either destroyed or burned in the fire that was caused by the quake. It also caused a tsunami that destroyed 155 houses and killed 60 people. The total number of deaths was more than 140,000.
10. Ashgabat Earthquake, 1948
This earthquake struck Ashgabat in Turkmenistan and some nearby villages. With a magnitude of 7.3, this earthquake caused extreme damage. Almost all brick buildings collapsed, and concrete structures were so damaged. The total number of deaths reached about 110,000 persons.
- Most earthquakes last for less than a minute.
- Earthquakes can occur in any kind of weather.
- The Ring of Fire is the most seismically and volcanically active zone in the world.
- Earthquakes are sometimes called earth tremors.
- When two or more of Earth’s tectonic plates are pushed together, they could form large mountain ranges. For example, the Himalayas and the Andes were formed by the movement of tectonic plates.
Frequently Asked Questions
Q: What are the causes of earthquakes?
A: Earthquakes are caused by the movement and interaction of tectonic plates, which are large pieces of the Earth’s crust that float on the semi-fluid layer beneath them.
Q: How long do earthquakes last?
A: The duration of an earthquake can vary. Some earthquakes last only a few seconds, while others may last for several minutes, but the most significant shaking typically lasts for a shorter duration.
Q: Can earthquakes be predicted?
A: While scientists can’t predict exactly when and where an earthquake will happen, they can study patterns and monitor fault lines to estimate the likelihood of earthquakes occurring in specific areas.
Q: How are earthquakes measured?
A: Earthquakes are measured using a scale called the Richter scale or the moment magnitude scale (Mw). These scales measure the energy released by an earthquake and assign it a numerical value.
Q: What is an aftershock?
A: An aftershock is a smaller earthquake that occurs after a larger earthquake in the same area. They can happen for hours, days, or even months after the main earthquake and can sometimes be felt.
Q: Can earthquakes cause tsunamis?
A: Yes, earthquakes that occur under the ocean floor or near coastal areas can cause tsunamis. When the seafloor suddenly moves, it can displace a large amount of water, triggering powerful and destructive ocean waves.
Q: Are all earthquakes felt on the surface?
A: No, not all earthquakes are felt on the surface. Some earthquakes occur deep underground or in remote areas where people may not feel the shaking. However, sensitive instruments can still detect them.
Q: Can buildings collapse during an earthquake?
A: Buildings and structures can be damaged or collapse during strong earthquakes, especially if they were not built to withstand the shaking. Building codes and regulations help ensure structures are designed to withstand seismic forces.
Q: Where do most earthquakes occur?
A: The majority of earthquakes occur along the edges of tectonic plates. Regions like the Pacific Ring of Fire, which encircles the Pacific Ocean, and the Mediterranean region are known for frequent seismic activity.
Q: What should I do during an earthquake?
A: During an earthquake, it’s important to remember to “Drop, Cover, and Hold On.” Drop to the ground, take cover under a sturdy piece of furniture, and hold on until the shaking stops. Afterward, be cautious of potential aftershocks and follow safety instructions.