The term used to describe when magma rises to the surface but does not occur at a boundary is intraplate volcanism.

Here's a breakdown:

* Intraplate: Means "within a plate" referring to a tectonic plate.

* Volcanism: Refers to any volcanic activity, including the eruption of magma.

Intraplate volcanism occurs in the middle of tectonic plates, away from the boundaries where most volcanic activity happens. This type of volcanism is often associated with:

* Hotspots: Areas where plumes of hot mantle material rise from deep within the Earth, melting the overlying crust and creating volcanoes.

* Plate stretching: As plates stretch, the crust becomes thinner and weaker, making it easier for magma to rise.

Examples of intraplate volcanism include the Hawaiian Islands and Yellowstone National Park.