How do volcanoes irrupt?

Answer:
The Earth's crust is made up of huge slabs called plates, which fit together like a jigsaw puzzle. These plates sometimes move.
Between the Earth's crust and the mantle is a substance called magma which is made of rock and gases.
When two plates collide, one section slides on top of the other, the one beneath is pushed down. Magma is squeezed up between two plates.
Contributor: Conrad
First answer by Conrad Cheung. Last edit by Caitlyn 1310. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 6 [recommend question].