What Are Mountains and Hills?
Mountains and hills are raised areas of land that stick up from the surrounding ground. The main difference is that mountains are much taller and steeper than hills. But both are created by the same amazing forces working deep beneath our feet.
The Earth's Crust is Always Moving
Did you know that the ground you're standing on is actually moving? The Earth's crust (the rocky outer layer) is split into huge sections called tectonic plates. These plates are constantly shifting, very, very slowly. They move just a few centimetres each year—about as fast as your fingernails grow.
Think of it like a jigsaw puzzle that's slowly being rearranged. The puzzle pieces (tectonic plates) bump into each other, slide past each other, and sometimes overlap.
Three Ways Mountains Form
Collision mountains form when two tectonic plates bump into each other head-on. When they crash together, the rock gets pushed upward to create enormous peaks. The Himalayas, the world's tallest mountain range, was formed this way. Two plates collided millions of years ago and are still pushing upward today.
Fold mountains happen when plates don't crash directly into each other but instead slide sideways and squeeze the rock in between. The rock gets folded and crumpled like a wrinkled carpet, creating wavy ridges and valleys.
Think of it like pushing two sides of a rug toward each other—the middle bunches up into folds and waves.
Volcanic mountains form when hot melted rock called lava erupts from inside the Earth. When a volcano erupts again and again over thousands of years, the lava builds up in layers, creating a cone-shaped mountain.
It Takes a Very Long Time
Mountains don't appear overnight. It takes millions of years for enough rock to push up and build a mountain tall enough to see from far away. Even though the movement is tiny each year, over millions of years it adds up to thousands of metres of height. The forces at work are so powerful that they can bend, break, and completely reshape the Earth's surface.