Seismic Waves

Seismic waves are the energy released by earthquakes, radiating outward in all directions from their source.

As seismic waves travel through Earth's layers, they change speed and direction. At boundaries like the crust-mantle interface, they can refract or reflect. Their speed increases in solid, dense materials and decreases in liquid or less dense ones.

A seismic wave consists of a high point known as a crest and a low point known as a trough. The height of a wave from its centerline to the crest is called its amplitude, while the distance from one crest to the next is its wavelength.

Seismic waves are categorized into two types: body waves and surface waves.

Body waves travel through Earth's interior, while surface waves move along the ground's surface.

During an earthquake, body waves arrive first, causing the sharp jolts people feel. Surface waves follow, producing rolling motions responsible for most of the destruction.

Although surface waves are the slowest, they are also the most destructive, causing intense shaking and significant structural damage.