Maavärinelainete

Maavärinelainete, often translated as seismic waves, are vibrations that travel through the Earth, usually caused by earthquakes. They can also be generated by volcanic eruptions, large landslides, and artificial explosions. These waves are the primary way scientists study the Earth's interior, as they allow us to infer the composition and structure of subsurface layers without direct observation.

There are two main categories of seismic waves: body waves and surface waves. Body waves travel through the Earth's interior. The fastest are P-waves (primary waves), which are compressional waves that cause particles to move back and forth in the same direction as the wave's propagation. S-waves (secondary waves) are slower and are shear waves, causing particles to move perpendicular to the direction of wave travel. S-waves cannot travel through liquids, which is how scientists determined the Earth has a liquid outer core.

Surface waves travel along the Earth's surface. Love waves are faster than Rayleigh waves and cause horizontal shearing motion. Rayleigh waves are the slowest but often the most destructive, producing a rolling motion that moves the ground both vertically and horizontally. The amplitude of seismic waves typically decreases with distance from the source, but their energy can be detected by seismometers located all over the world. The study of seismic waves is crucial for understanding earthquake mechanics, predicting seismic hazards, and exploring for natural resources.