Journey to the Centre of the Earth: Exploring Earth’s Layers

• New lesson editor
• Science
• Secondary Education

Learning Objective

At the end of this lesson you will be able to name Earth's main layers, describe their properties, and answer questions about their temperature and state (solid or liquid).

What do you already know about the layers of the Earth?

What Are the Layers of the Earth?

The Earth is made up of three main layers: the crust, the mantle, and the core. Each layer is different in thickness, material, and temperature.

The Crust: Earth's Thin Skin

The crust is the thinnest layer. It is where we live, and contains rocks, soil, oceans, and mountains. It is solid and between 5 and 70 kilometres thick.

The Mantle: Hot and Flowing

The mantle is beneath the crust. It is very hot and made of solid rock that can flow slowly. The mantle is about 2,900 kilometres thick.

The Core: Outer and Inner

The core is split into two parts: the outer core and the inner core. The outer core is liquid metal (iron and nickel), while the inner core is solid metal. The core is extremely hot.

Temperature and State

Temperature

Solid or Liquid?

The temperature increases as you go deeper. The crust is coolest, the mantle is hotter, and the core is hottest (up to 5,500°C).

Crust and mantle are solid (mantle can flow). Outer core is liquid. Inner core is solid because of high pressure.

Label the Diagram

Quick Quiz: Test Yourself

1. Name the three main layers of the Earth. 2. Which layer is liquid? 3. Which layer is the thinnest? 4. Where is it hottest inside the Earth?

Key Facts to Remember

Crust: Thin, solid, where we live. Mantle: Thick, hot, solid rock that flows. Core: Iron and nickel, very hot, with a liquid outer part and solid inner part.

Reflection

How might knowing about Earth’s layers help us understand volcanoes and earthquakes?

Write down 3 things you learned in this lesson.

Write down 2 things you want to know more about.

Ask 1 question about something you haven't quite understood yet.