Earth’s Structure

Diagram of Thermal Convection

Surachit: Creative Commons 3.0

In this topic, you learned that the Earth has four major layers and two sub layers. The major layers are the crust, mantle, inner core, and outer core. The sub layers are the lithosphere and the asthenosphere.

You also learned that the crust is in balance with the mantle and adding weight to the crust causes it to sink further into the mantle. As you now know, the lithosphere moves by thermal convection.

You will explore thermal convection in the next topic and how this process helped spread the continents to their current locations.