What sort of volcano is the one in the book?

 

Stratovolcano

The volcano in How BIG is BIG? is a stratovolcano

Stratovolcanos are made by hot magma (the melted rock) coming up through the Earth at the edges of continental plates. The layers of magma build up with layers of volcanic ash (which are small bits of crushed rock also called tephra) one on top of the other. If you cut the volcano in half it would look a bit like a layer cake with the different flavours laid one on top of the other.

Stratovolcanos can also be called compostite volcanos because they are composed (made) from different things.

Stratovolcanos usually have the classic cone or conical shape that we normally think of when we imagine one in our heads.

A couple of really good examples of stratovolcanos are Mount Etna in Sicily, Italy and Arenal in Parque Nacional Volcan Arenal, Costa Rica. These two volcanos are very active and have exploded many times, spewing out lots of lava and putting a huge amount of dust and rock into the air around them.