Why do ocean waves only crash and break when they reach the shore?
Standing in the surf: wave after wave rises up and curls over right before it hits you — but out where the swimmers are, the water just gently lifts them. Same sea, so why do they only crash at the shore?
Talk about it
- Next time you're at the beach, watch one wave from far out until it crashes. Where exactly does it start to curl over?
- Out where the swimmers float, the water just lifts them. At the sand it crashes. Same water — so what changed underneath?
- Make a wave in the bathtub and tilt a tray as a 'beach.' Does a steeper tray make a bigger splash?