Why Do Volcanoes Have Different Shapes?

Volcanoes come in different shapes as a result of different types of eruptions and different volcanic materials present in the volcano. The three main volcano shapes are the cinder cone, the shield volcano and the stratovolcano.

All volcanoes have a magma chamber inside, a crater at the mouth of the volcano and a central vent that brings material up from the magma chamber to the crater.

Cinder cone volcanoes, also known as scoria cone volcanoes, are typically under 300 meters tall, with straight sides and a wide crater at the summit. These are the most common type. A cinder cone volcano is typically formed from an explosive eruption in which cinders are the primary materials ejected. Most cinder cone volcanoes only erupt once.

Stratovolcanoes exhibit the characteristic volcano shape. They are tall and wide, with steep upper slopes and gentle lower slopes. They are built through a series of dramatic explosions that send out large amounts of pyroclastic ash and lava. Because stratovolcanoes erupt over and over again, they change their shape and grow over time.

Shield volcanoes are short but wide, resembling a traditional shield set on the ground. They are formed from slow eruptions of flowing lava, which is made up of melted basalt at extremely high temperatures. Shield volcanoes tend to erupt often and the eruptions continue for long periods of time.