Transcript Slide 1

Which one is the odd one out?
Which one is the odd one out?
Which one is the odd one out?
How do waves affect the coast?
Although waves may sometimes result from
submarine earth movements, they are
usually formed by the wind blowing over
the sea. The size of a wave depends upon
the:
• Strength of the wind;
• Length of time which the wind blows;
• Distance of the sea which the wind has to
cross
Why do waves break?
wavelength
the bottom of the wave touches the sand, slows
down and the top of the wave topples over
Why do waves break?
Do you think the waves will be strong
waves or weak?
Do you think the waves will be strong
waves or weak?
Pacific Ocean
What island is this?
Do you think the waves will be strong
waves or weak?
Y
X
Strong winds from the south west
have been blowing for three days
after crossing 1000km of ocean.
X
Gentle winds from the south west
have been blowing for one day
after crossing 10km of ocean.
Y
Give three reasons why the waves at X are likely to be higher
and more powerful than the waves at Y.
Types of waves
Destructive Waves
backwash>swash
Constructive Waves
swash>backwash
• Would destructive waves cause erosion or
deposition?
• Would constructive waves cause erosion
of deposition?
• What type of waves come into contact with
a spit?
• What type of wave come into contact with
a Stack?
Cliffs
Wave-cut platform
The waves attack the base of the cliff through the processes
of abrasion, corrosion, hydraulic action and attrition.
Over time the cliff will be undercut and a wave-cut notch is
formed.
Eventually the cliff becomes unstable and collapses. Further
cliff retreat will form a wave-cut platform.