Build a volcano model

A volcano is an opening in Earth's crust where molten rock, ash, and gases escape from below the surface. Volcanoes are powerful reminders of the energy stored deep inside our planet. In this project lesson, you will explore how volcanoes form and connect what you have learned about Earth's layers.

How a Volcano Forms

1. Deep inside Earth, extreme heat melts rock into a thick liquid called magma.
2. Magma collects in a magma chamber beneath the surface.
3. Pressure builds as more magma accumulates and gases form.
4. When pressure becomes too great, magma forces its way up through a crack called a vent.
5. When magma reaches the surface it is called lava. Ash and gases are also released during an eruption.

Parts of a Volcano

• Magma chamber — a reservoir of molten rock deep underground.
• Vent — the channel that carries magma from the chamber to the surface.
• Crater — the bowl-shaped opening at the top of the volcano.
• Lava — molten rock that has erupted onto the surface.
• Ash cloud — tiny fragments of rock and minerals blown into the air during an eruption.

Connection to Earth's Layers

Earth has four layers: the crust (thin outer shell), the mantle (thick layer of hot, slowly moving rock), the outer core (liquid iron and nickel), and the inner core (solid iron and nickel). Magma originates in the upper mantle where temperatures and pressures are high enough to melt rock.

Plate Tectonics and Volcanoes

• Earth's crust is divided into large pieces called tectonic plates that move slowly over the mantle.
• Most volcanoes form along plate boundaries where plates meet or pull apart.
• The "Ring of Fire" around the Pacific Ocean has the highest concentration of volcanoes on Earth.
• Volcanic eruptions can build new land, change climate, and affect ecosystems.