How Does the Rock Inside a Volcano Get So Hot?

The rocks inside a volcano melt into a mass called magma, and it’s really, really hot. But why?

Deep inside our Earth, there’s a lot of heat. This heat comes from two main sources. First, when our planet was formed about 4.5 billion years ago, it started off very hot because of all the energy from crashing particles. Over time, it has been cooling down, but the center is still super hot.

Second, there are radioactive elements like uranium inside the Earth. When these elements break down, they release heat. It’s like how a battery gives off a little warmth when it’s being used.

Both these sources of heat make the rock deep inside our Earth melt. This melted rock is magma. To give you an idea of how hot it is: water boils at 100°C (212°F), but magma can be anywhere from 700°C to 1,300°C (1,300°F to 2,400°F)!

When magma rises towards the Earth’s surface, it can form volcanoes. So, next time you think of a volcano, imagine a pot of super-hot melted rock deep inside our planet, warmed up by the Earth’s ancient heat and natural “batteries.”