What does a magma chamber look like?

We imagine that the magma chamber beneath a volcano is a cavity full of magma. But the magma chamber is rather a complex system of fractures in the Earth’s crust that contain some magma.

We obtain clues on the structure of the magma chamber through the analysis of seismic waves under volcanoes. Because seismic waves do not travel through magma the same way they travel through solid earth, precise seismic studies under a volcano can determine the magma chamber’s overall structure.