Structure of Earth facts for kids

Our planet Earth is like a giant onion, made up of several different layers. Each layer has its own special job and is made of different materials. Understanding these layers helps us learn how Earth works, from earthquakes to volcanoes, and even why we have a magnetic field that protects us!

Earth's Amazing Layers

Imagine cutting the Earth in half, like an apple. You would see distinct layers, each with unique features. These layers are the crust, the mantle, the outer core, and the inner core. They all work together to make our planet dynamic and alive.

The Crust

The crust is the outermost layer of Earth. It's like the skin of an apple, very thin compared to the other layers. This is where we live! It includes all the land we walk on, like continents and islands, and also the ocean floor.

• Thickness: The crust is usually about 5 to 70 kilometers (3 to 43 miles) thick. It's thinnest under the oceans (oceanic crust) and thickest under mountains (continental crust).
• What it's made of: The crust is made of solid rocks. Oceanic crust is mostly made of a dark, heavy rock called basalt. Continental crust is lighter and made of rocks like granite.
• Temperature: The temperature of the crust increases with depth, but it's generally much cooler than the layers below.

The Mantle

Below the crust is the mantle, which is the thickest layer of Earth. It makes up about 84% of Earth's total volume! The mantle is not completely solid; it's made of very hot, dense rock that flows very, very slowly. Think of it like super-thick, gooey caramel.

• Thickness: The mantle is about 2,900 kilometers (1,800 miles) thick.
• What it's made of: It's mostly made of silicate rocks rich in iron and magnesium.
• Movement: The rock in the mantle moves in slow currents, like water boiling in a pot. These movements are called convection currents. They are incredibly important because they cause the Earth's crust to move, leading to earthquakes, volcanoes, and the movement of continents over millions of years. This process is called plate tectonics.
• Temperature: Temperatures in the mantle range from about 500°C (900°F) near the crust to over 4,000°C (7,200°F) closer to the core.

The Outer Core

The outer core is a super-hot, liquid layer that surrounds the Earth's solid inner core. It's like a giant ocean of molten metal!

• Thickness: This layer is about 2,400 kilometers (1,500 miles) thick.
• What it's made of: It's mostly made of liquid iron and nickel, with some other lighter elements.
• Movement: The liquid metals in the outer core are constantly swirling and moving. This movement creates electric currents. These currents, in turn, generate Earth's powerful magnetic field.
• Earth's Magnetic Field: The magnetic field acts like a giant invisible shield around our planet. It protects us from harmful particles from the sun, like the solar wind, which could strip away our atmosphere. Without this magnetic field, life on Earth as we know it might not be possible!
• Temperature: The temperature in the outer core is extremely hot, ranging from about 4,400°C (8,000°F) to 6,100°C (11,000°F).

The Inner Core

At the very center of our planet is the inner core. Even though it's incredibly hot, it's a solid ball! This is because the immense pressure from all the layers above it is so strong that it keeps the iron and nickel from melting, even at extreme temperatures.

• Size: The inner core has a radius of about 1,220 kilometers (760 miles), which is roughly the size of the Moon!
• What it's made of: It's primarily made of solid iron and nickel.
• Temperature: The inner core is the hottest part of Earth. Its temperature is estimated to be around 5,200°C (9,400°F) to 6,200°C (11,200°F). This is as hot as the surface of the sun!
• Pressure: The pressure in the inner core is about 3.6 million times the pressure at the Earth's surface. This incredible pressure is what keeps it solid.

Images for kids

• 

  World map showing the position of the Moho.

See also

In Spanish: Estructura de la Tierra para niños