What are the sources of energy ? Flashcards
What are the sources of energy ?
- Waves
- Wind
- Tides
- Sea currents
What is the wavelength ?
This is the distance between successive crests
What is the crest ?
The highest point of a single wave
What is the wave height ?
This is the difference between a wave crest + trough
What is the trough ?
The lowest point of a single wave
What is the wave frequency / wave period ?
This is the time for one wave to travel the distance f one wavelength, or the time between one crest and the following crest passing a certain point
How does wind play an important part in wave formation ?
Waves are created by the transfer of energy from the wind blowing over the sea surface. (Referred to the frictional drag of the wind)
What happens when the wave approaches shallow water ?
When the wave approaches shallow water, the friction with the sea bed increases, so the base of the wave slows down. This increases the height of the wave and steepness of the wave until the upper part plunges forward and he wave breaks onto the shore (1:7)
What is the fetch ?
The distance over which the wind is blowing
Which direction is the prevailing wind ?
South West
What affects the waves ?
- Fetch
- Prevailing wind
- Strength of wind
- Duration of wind
What are the characteristics of a destructive wave ?
- Steeper beaches
- Plunging
- High energy
- Weak swash
- Strong backwash
- Tall wave height
- Short wavelength
- High frequency > 10-14 /min
- More sediment is removed
What are the characteristics of a constructive wave ?
- Gentle beaches
- Spilling waves
- Low energy
- Strong swash
- Weak backwash
- Low height
- Long wavelength
- Low frequency > 6-8 /min
- Beach material builds up
Give an example of negative feedback ?
Destructive waves > makes beach steeper > making constructive waves > builds the beach back
