An earthquake is a quick shaking of the ground.
It happens when the Earth’s outer layer, called the crust, breaks or moves.
This shaking can be small or very big, and it usually doesn’t last long — just a few seconds or minutes.
Real-Life Example:
Have you ever jumped on a trampoline?
When you land, the surface moves up and down.
That’s kind of like what happens during an earthquake.
Except, instead of you jumping, the Earth is moving!
What Causes Earthquakes? | Fun Science for Kids
The Earth Has Layers
To understand earthquakes, we need to know what the Earth is made of.
The 4 Main Layers of Earth:
Crust – The outermost layer where we live. It’s made of rocks and looks like a giant puzzle made of plates.
Mantle – A thick layer of hot, soft rock below the crust.
Outer Core – A liquid layer made of melted metals.
Inner Core – The solid, very hot center of the Earth.
Fun Fact:
The crust is like the skin of an apple — very thin compared to the whole Earth!
What Are Tectonic Plates?
The Earth’s crust isn’t one big piece.
It is made of huge pieces called tectonic plates.
These plates fit together like puzzle pieces and float on the soft mantle underneath.
What Do These Plates Do?
These plates move slowly — about as fast as your fingernails grow!
Sometimes they slide past each other, push against each other, or pull away from each other.
This movement is called plate tectonics.
How Do Earthquakes Happen?
When Plates Push or Slide
When tectonic plates move, they can get stuck because the edges are rough.
Pressure builds up.
Eventually, the plates suddenly slip or break free.
This sudden movement causes the ground to shake — that’s an earthquake!
The Focus and Epicenter
The Focus is the spot underground where the earthquake starts.
The Epicenter is the spot on the Earth’s surface right above the focus.
Think of it like a firecracker in the ground.
The focus is where the explosion happens, and the epicenter is where you feel it first.
Types of Plate Movements That Cause Earthquakes
There are three main ways tectonic plates move that cause earthquakes:
Transform Boundaries – Sliding Past Each Other
Plates move side by side in opposite directions.
The friction causes shaking.
Example: San Andreas Fault in California, USA.
Convergent Boundaries – Pushing Together
Plates crash into each other.
One plate may go under the other (subduction).
This creates strong earthquakes and even volcanoes.
Example: Himalayan Mountains (India and Nepal region).
Divergent Boundaries – Pulling Apart
Plates move away from each other.
Magma (hot liquid rock) rises to fill the space.
This can cause smaller earthquakes and new crust to form.
Example: Mid-Atlantic Ridge (in the ocean).
What Is a Fault Line?
A fault is a crack in the Earth’s crust.
Most earthquakes happen along these fault lines.
Example:
Imagine breaking a cookie.
The crack in the middle is like a fault.
If you push both sides of the cookie, it might suddenly snap — that’s like an earthquake!
How Are Earthquakes Measured?
Scientists use a special tool called a seismograph to measure earthquakes.
Richter Scale
This scale tells us how strong the earthquake is.
It goes from 1 to 10.
The higher the number, the stronger the earthquake.
1-3: Very small, most people don’t feel it.
4-6: Shakes buildings, can break things.
7+: Strong and dangerous.
What Damage Can Earthquakes Do?
Earthquakes can cause:
Buildings to fall
Bridges to break
Roads to crack
Landslides and tsunamis
But not all earthquakes are dangerous.
Many are too small to feel.
What Is a Tsunami?
Sometimes, an earthquake happens under the ocean.
It pushes the water and causes huge waves called tsunamis.
These waves can flood cities near the sea and be very dangerous.
Example:
In 2004, an undersea earthquake near Indonesia caused a giant tsunami that affected many countries.
How Do We Stay Safe During an Earthquake?
Even though we can’t stop earthquakes, we can prepare for them.
Earthquake Safety Tips:
Drop, Cover, and Hold On
Drop to the ground
Cover your head under a table or desk
Hold on until the shaking stops
Stay Away from Windows and Heavy Objects
Have an Emergency Kit
Water, flashlight, food, and a first-aid box
Practice Earthquake Drills at School or Home
How Do Scientists Study Earthquakes?
Scientists who study earthquakes are called seismologists.
They use:
Seismographs to record the shaking
Earthquake maps to find danger zones
Computer models to predict future earthquakes
Where Do Most Earthquakes Happen?
Earthquakes often happen in places near plate boundaries.
These are known as earthquake zones.
Most Active Earthquake Areas:
Ring of Fire – A circle of volcanoes and earthquakes around the Pacific Ocean (Japan, Philippines, California, etc.)
Himalayas – In India, Nepal, and nearby countries
Cool Earthquake Experiment (Try with Supervision!)
What You Need:
A tray of jelly
A small cardboard house or toy
A spoon
Steps:
Place the toy house on the jelly tray.
Gently shake the tray side to side.
Watch how the jelly moves and the house wobbles!
This shows how the ground shakes and why buildings need strong foundations!
How Do Engineers Make Buildings Safer?
In places where earthquakes happen often, people build earthquake-proof buildings.
Features Include:
Strong steel frames
Shock absorbers
Deep foundations
Flexible materials that can bend without breaking
