The earthquake magnitude communicates its energy level, and the intensity communicates its strength based on its effects.

Meanwhile, one hypothetical magnitude 7.8 earthquake on the San Andreas fault could send “extreme,” or Intensity 10, shaking across most of urbanized Southern California.

Magnitude and Intensity measure different characteristics of earthquakes. Magnitude measures the energy released at the source of the earthquake.

Quakes are measured by magnitude — a measure of how much energy it produced. They’re also measured by intensity — how strong of a shake did people feel from a temblor.