Earthquake

geology · Earth · powerful

Sudden energy burst. An earthquake happens when energy stored in Earth's outer layer is suddenly released, sending shaking waves through the ground.

Seismic waves. The released energy travels as waves called seismic waves, which ripple outward and make the surface shake.

Big and small. Some earthquakes are so weak nobody can feel them, while others are strong enough to damage whole cities.

Tracking the shakes. Scientists study how often, how big, and what type of earthquakes happen in an area to understand its activity.