2.2. Types Of Waves Flashcards
What is the formation of constructive waves?
Distant weather systems generate these waves in the open ocean
Light wind
What is the wave form in constructive waves?
Low rolling waves with a long wavelength
What is the wave break of a constructive wave?
Strong swash
Weak backwash
What is the beach gain/loss of a constructive wave?
Beach gain
What is the beach profile of a constructive wave?
Usually associated with a gentle beach profile although, over time, they will build up the beach and make it steeper.
What is the formation of a destructive wave?
Local storms are responsible for these waves
What is the wave form of destructive waves?
High, plunging waves with a short wavelength
What is the wave break of destructive waves?
Weak swash
Strong backwash
What is the beach gain/loss of a destructive wave?
Beach loss
What is the beach profile of a destructive wave?
Usually associated with a steeper beach profile although, over time, they will flatten the beach
What factors affect wave energy?
- Strength of the wind
- Duration of the wind
- The fetch
How are waves created?
As air moves across water, frictional drag disturbs the surface and forms ripples or waves.
In the open sea, there is horizontal movement of water.
Instead, there is an orbital movement of the water particles.
Close to the coast, horizontal movement of water does occur as waves are driven onshore to break on the beach.
How are beaches and waves a negative feedback loop?
- Constructive waves = gentle
- Over time as more beach material is deposited, the profile steepens
- Because it’s steeper, the waves become more destructive over time, removing sediment from the beach
- This then reduces the gradient of the beach
- However, the beach is never at dynamic equilibrium due to things like weather and wind strength
What is a neap tide?
- Moon at right angles to the sun when in first quarter or last quarter
- Gravitational pulls act against each other to create lower high tides and higher low tides
What is a spring tide?
- Sun and moon in line at full moon or new moon
- Gravitational pulls act together to create higher high tides and lower low tides