Coasts

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COASTS:

How waves form:

Waves are formed by friction with the surface of the water causes ripples to form and these develop into waves. The stretch of open water over which the wind blows is called the fetch. The longer the fetch, the more powerful a wave can become.

Waves reaching the coast:

Despite the wavy motion of the water surface, there is little horizontal transfer of water. It is only when the waves approach the shore that there is forward movement of water as waves break and wash up the beach.

The seabed interrupts the circular orbital movement of the water. As the water becomes shallower, the circular motion becomes more elliptical. This causes the crest of the wave to rise up and then eventually topple onto the beach. The water that rushes up the beach is called the swash. The water that flows back towards the sea is called the backwash.

Types of wave found at the coast:

Constructive Waves: are waves that surge up the beach with a powerful swash. They carry large amounts of sediment and 'construct' the beach, making it more extensive. They are formed by distant storms, which can be hundreds of kilometres away. The waves are well spaced apart and are powerful when they reach the coast.

Destructive Waves: are formed by local storms close to the coast. They are so named because they 'destroy' the beach. They are closely spaced and often interfere with each other, producing a chaotic, swirling mass of water. They rear up to form towering waves before crashing down onto the beach. There is little forward motion when a destructive waves breaks, but a powerful backwash. This explains the removal of sediment and the destruction of the beach.

Weathering:

COASTS:

How waves form:

Waves are formed by friction with the surface of the water causes ripples to form and these develop into waves. The stretch of open water over which the wind blows is called the fetch. The longer the fetch, the more powerful a wave can become.

Waves reaching the coast:

Despite the wavy motion of the water surface, there is little horizontal transfer of water. It is only when the waves approach the shore that there is forward movement of water as waves break and wash up the beach.

The seabed interrupts the circular orbital movement of the water. As the water becomes shallower, the circular motion becomes more elliptical. This causes the crest of the wave to rise up and then eventually topple onto the beach. The water that rushes up the beach is called the swash. The water that flows back towards the sea is called the backwash.

Types of wave found at the coast:

Constructive Waves: are waves that surge up the beach with a powerful swash. They carry large amounts of sediment and 'construct' the beach, making it more extensive. They are formed by distant storms, which can be hundreds of kilometres away. The waves are well spaced apart and are powerful when they reach the coast.

Destructive Waves: are formed by local storms close to the coast. They are so named because they 'destroy' the beach. They are closely spaced and often interfere with each other, producing a chaotic, swirling mass of water. They rear up to form towering waves before crashing down onto the beach. There is little forward motion when a destructive waves breaks, but a powerful backwash. This explains the removal of sediment and the destruction of the beach.