Where do the majority of volcanoes occur?

• A. In long belts at the margins of tectonic plates.
• B. Along ridges in the middle of tectonic plates.
• C. Only on continental interiors.
• D. Only at hotspots.

Answer: (A)

Volcanic activity is driven by movement at tectonic plate boundaries. Where plates interact, rock melts to form magma that can rise to the surface and erupt. This happens most extensively along long belts around the edges of many plates, especially at subduction zones where one plate sinks beneath another, and at divergent boundaries where magma rises as plates move apart. Because these boundary processes create broad, continuous belts of volcanism around the planet, the majority of volcanoes are found there, with the Pacific Ring of Fire as the best-known example. Volcanoes that form away from plate margins—such as those at hotspots inside plates—exist, but they are far less numerous overall, so they don’t define the global pattern.