Volcanoes and Earthquakes - Frequently Asked Questions

Why do volcanoes erupt?

Volcanoes erupt when some of the hot magma (liquid rock) from below the Earth’s surface squeezes up through holes in the surface. Magma is so hot that it melts solid rock in its path and makes a tunnel through the crust just below the surface. Gradually, more and more magma builds up there, until suddenly the volcano erupts and the hot liquid rock spurts into the air.

What is a volcanic island?

When a volcano erupts on the ocean floor, the hot liquid rock cools and sets into hard rock. Each time the volcano erupts, it gets a bit larger as more liquid rock piles up and hardens on its sides. Eventually, it becomes a tall underwater mountain with its tip sticking out above the water, forming an island.

Did you know?

Several million earthquakes happen around the world every year, but most are so small that people do not even know they have happened.

Why did earthquakes happen?

Earthquakes happen because the plates that makes up the Earth’s crust are moving like giant rafts on the bubbling magma below. These plates usually slide against each other gently, but sometimes two plates get stuck and push hard against each other. When they suddenly jolt apart again, this sudden movement creates the violent shaking at the Earth’s surface as earthquakes.

How do earthquakes cause damage?

When small earthquakes shake the land they may simply knock books from shelves, but large earthquakes can make buildings and roads crumble. They can create huge cracks in the land into which whole lakes disappear. Some earthquakes set off landslides, where huge amounts of soil slide down a hill and bury buildings at the bottom.