Stratovolcano (Composite Volcano)

**Stratovolcanoes** (also known as **composite volcano**) are large, steep structure in a form of **cone**, built upon alternating **lava** and **ash layers**. They are one of the oldest mountain structures of the Earth, reaching almost 2 500 metres above the base.

**Magma** is being stored in the **magma chamber**, opening beneath the volcano, which is protected by strong, solid rock. When the magma erupts, it charges itself through the **main vent** and releases through **crater**. This reaction is accompanied by launch of **bomb**s (twisted blocks of hot lava) and **ash** (melted or solid particles containing rock and glass). Upon hitting the surface, magma becomes **lava** and flows downhill the cone, until it cools down and solidifies, creating a **lava layer** and enlarging the cone. **Secondary vent** can be created, but its power is significantly lower than of the main vent.