What’s the Difference Between Lava and Magma?
When volcanoes erupt, magma is liquid rock within the interior of the Earth. But as molten rock finds its way to the surface, we refer to it as lava.
So the main difference between magma and lava is location.
Magma is within the interior of the Earth. But lava is on the outside.
Let’s explore the differences between lava and magma with a bit more detail.
Magma is within the Earth
We find both magma and lava at volcanoes. In fact, it’s this liquid rock that pools in the magma chamber. But we know it’s magma when it’s within the surface of Earth.
Magma is liquid rock with dissolved gas. As pressure builds up, the gas expands and explodes at the mouth of the volcano.
Different kinds of volcanoes lock in different types magma underground. It’s from the various types of magma that differentiate the types of volcanoes.
After magma flows upwards from the mantle beneath, lava reaches the surface. When the lava hardens, it becomes dark igneous rock like “basalt”.
Lava flows outside of volcanoes
Volcanoes erupt because of the expansion of gases at the mouth of the volcano. Like hot wax dripping down a candle, lava spews and flows downhill.
When it hardens, it becomes igneous rocks like granite. This is why volcanoes are the foundation for igneous rocks.
They’re also vital in the rock cycle. This is why geologists often refer to igneous rocks as the starting point of the rock cycle.
Not only do volcanoes spew out lava, but also water. But because water won’t sit on lava, it evaporates into a gas. So you often have water vapor forming clouds near volcanic eruptions mixed with ash with lightning strikes.