What causes magma to rise to the surface?

Magma is a mixture of molten and semi-molten rock found beneath the surface of the Earth. ... Decompression melting often occurs at divergent boundaries, where tectonic plates separate. The rifting movement causes the buoyant magma below to rise and fill the space of lower pressure. read more

The pressure of the volcano builds up inside the underground feature (volcano) until it can't hold anymore so it BURSTS out!. read more

Quick Answer. Magma rises to the surface because it is less dense than the surrounding rocks and a structural zone in the Earth's crust enables movement. read more