Why are earthquake waves recorded differently as P waves and S waves?
Quick Answer
P waves are compressional waves that travel through solids and liquids, while S waves are shear waves that only move through solids. Their different speeds help scientists locate earthquakes and study Earth’s interior.
The Full Story
Primary or P waves push and pull material in the same direction they travel, so they move faster and arrive first at seismographs. Secondary or S waves move material at right angles to their direction of travel and cannot pass through liquids, which is why they disappear in Earth’s outer core. The speed gap between P and S waves lets seismologists estimate how far away an earthquake was. It also helped prove that Earth has a liquid outer core, a major discovery in early 20th-century geophysics.
Key Facts
YouTube Angle
Suggested video title for this topic:
"Two types of earthquake waves helped reveal Earth’s hidden core — here’s how."
Was this answer helpful?
Tap a reaction — it helps us pick what to cover next.