How Volcanoes Form And Erupt

Formation of Volcanoes

The Earth’s surface is made up of large pieces called tectonic plates. These plates slowly move over the Earth’s mantle, a layer of hot rock.

Volcanoes are formed when the earth’s plates move together (convergent) or apart (divergent).
Molten rock called magma collects in chambers under the Earth’s surface. When magma reaches the surface, it’s called lava.
When the lava cools and hardens, it forms the cone-shaped mountain we think of as a volcano.
Most of the world’s volcanoes are found around the edges of tectonic plates on land and in the oceans.

Eruption of Volcanoes

An eruption occurs when enough magma and gas pressure build up in the chamber under the volcano.

Cracks and Vents:

Eruption:

When the pressure is too high, the magma erupts through the vent and comes out as lava.

After the Eruption:

The volcano can continue to release gases, ash, and lava, building up over time.

Type of Eruptions

Some volcanoes explode while others gently flow lava because of the type of magma inside them.

Explosive Volcanoes:

Thick Magma: If the magma is thick and sticky, it traps gas bubbles.
High Gas Content: The trapped gas builds up pressure.
Big Explosion: When the pressure is too high, it causes a violent explosion.

Effusive (Gentle-Flow) Volcanoes:

Fun Facts

Here are some interesting facts about volcanoes:

Most of the world’s volcanoes are located in the “Ring of Fire,” a region around the edges of the Pacific Ocean.
Underwater volcanic eruptions formed islands like Hawaii.
Erupting volcanoes release gases like water vapor, carbon dioxide, and sulfur dioxide.
Mars has the largest volcano in the solar system, called Olympus Mons.

Review

Let’s quickly recap what we learned about volcanoes:

Basics of Genetics