Why do the waves break on reaching the shore and how does shore geometry affect it ?

Question

Why do the waves break on reaching the shore and how does shore geometry affect it ?

Answer 1

most waves are caused by winds which blow across the open sea. the height of a wave increases as winds grow in strength and, in stormy weather, waves may reach 12 metres or more in height.

in the open sea , however, waves do not move water particles horizontally. try this - tie a rope to a fence and then shake the rope, ripples or waves run through the rope, but the rope itself does not move forward. waves in the open sea are much like this. near coasts, the nature of waves changes. when the depth of the water is less than half of a wave length [the distance between two crests] the water is said to be shallow. in shallow water the rotating movement of the water drags against the bottom and slows down, causing the crests to move closer together. as the wave approaches the shore, the water in front is insufficient to complete the shape of the wave. it then breaks and water surges up the beach, falling back again as the next wave advances