The Juan de Fuca Ridge is an example of a mid-ocean ridge, a place where two of the Earth's tectonic plates are slowly moving apart from each other. Along the plate boundary, molten rock or magma rises up from deep in the Earth and creates new ocean floor. This is why Axial is such an active volcano.

The mid-ocean ridge system circles the entire Earth, somewhat like the seams of a baseball. Most of the volcanic eruptions on Earth occur on the mid-ocean ridge.