What is S-waves (secondary waves)?

S-waves are like shaking waves that move through the ground after an earthquake.

Imagine you're holding a rope at one end, and your friend is holding the other end. If you shake the rope up and down, it moves in a side-to-side motion, this is just like how S-waves travel through the Earth!

S-waves are called secondary waves because they arrive after the faster P-waves (which we can explain another time). While P-waves push and pull things straight ahead, S-waves make things move from side to side, like a jump rope in motion.

Think of it like this: if you're standing on a trampoline and someone shakes the edge, you go up and down, that's like a P-wave. But if they shake the edge from side to side, you bounce left and right, that’s an S-wave!

These shaking waves can only move through solid materials, not liquids or gases, so they help scientists figure out what’s deep inside our planet!