Which boundary has frequent earthquakes but little volcanism?

• A. Divergent
• B. Transform
• C. Convergent
• D. Hotspot

Answer: (B)

Transform boundaries are where two plates slide past one another horizontally. The sideways motion creates a lot of friction, so rocks continually deform until they snap and release energy as frequent earthquakes. There isn’t a lot of upwelling or melting at these edges, so magma doesn’t rise to form volcanoes, meaning volcanism is rare there. This combination—lots of earthquakes and little volcanism—is characteristic of transform boundaries. For context, the San Andreas Fault is a famous example. By comparison, divergent boundaries commonly have volcanic activity from upwelling magma, convergent boundaries often produce both strong earthquakes and volcanism due to subduction, and hotspots create volcanoes away from plate boundaries with fewer boundary-driven earthquakes.