Energy at Coast + Wave Type

What are some sources of energy at the Coast ?

• sun - primary source for all natural systems

• wind which forms waves offshore

• tectonic activity

Process of wave formation

• wind moves across surface of water

• this causes frictional drag = small ripples and waves

• this leads to a circular orbital motion of water particles in ocean

• seabed becomes shallower - orbit of water particles becomes more elliptical

• waves have more horizontal movement

• wave height increases however wavelength and wave velocity decrease

• this causes water to back up from behind the wave until the wave breaks

What are the factors affecting wave energy

• strength of wind

• duration of wind

• size of fetch

Constructive waves

• formation = formed by weather systems operating in an open system

• wavelength = long wavelength

• frequency = 6 - 9 per minute

• wave characteristics = low waves which surge up beach

• swash characteristics = strong swash, weak backwash

• effect on beach = gently sloped beaches

Destructive waves

• formation = localised storm events with stronger winds operating closer to coast

• wavelength = short wavelength

• frequency = 11 - 16 per minute

• wave characteristics = high waves, which plunge onto beach

• swash characteristics = weak swash, strong backwash

• effect on beach = steeply sloped beaches