Earthquakes provide evidence for plate tectonics because they are caused by movement of tectonic plates and usually occur at plate boundaries.

• A. They are caused by changes in Earth's magnetic field.
• B. They occur at the centers of plates.
• C. They are caused by movement of tectonic plates and usually occur at plate boundaries.
• D. They occur only during volcanic eruptions.

Answer: (C)

Earthquakes arise when rocks deform under stress from moving tectonic plates, and they release energy as seismic waves. The pattern of earthquakes lines up with plate boundaries because that's where most plate interactions—sliding past each other, pulling apart, or colliding—generate the stress that breaks rocks. Magnetic-field changes don’t cause earthquakes, and the centers of plates are typically steadier with less stress accumulation (intraplate quakes are rare exceptions). Earthquakes aren’t caused only by volcanic eruptions, though volcanic activity can trigger some, so the strongest evidence for plate tectonics is the link between plate movement and earthquakes occurring at boundaries.