The type of plate boundary most likely to lead to above-ground volcanic activity is a convergent plate boundary , specifically a subduction zone where one tectonic plate dives beneath another. This process causes melting of the subducted plate and the mantle above it, generating magma that rises to the surface and forms volcanoes. Volcanic arcs, including island arcs and Andean-type volcanoes, commonly form at these subduction zones. Volcanic activity also occurs at divergent boundaries where plates move apart allowing magma to rise, but subduction zones are most strongly associated with above- ground volcanic eruptions. Transform boundaries typically do not produce volcanic activity.
Key Points
- Subduction zone (convergent boundary): One plate goes under another, melts due to high heat and pressure, and magma rises to form volcanoes above ground (volcanic arcs).
- Divergent boundaries: Plates move apart and magma rises to form new crust, sometimes causing volcanoes (e.g., Mid-Atlantic Ridge and Iceland).
- Transform boundaries: Plates slide past each other with little to no magma generation, thus usually no volcanoes form.
Therefore, the most likely zone for above-ground volcanic activity is a subduction zone at a convergent plate boundary.
