Definition
 Undulation that forms as a disturbance moves along
the surface of the water
Anatomy of a wave
 Crest- highest part of a




wave
Trough- lowest part of the
wave
Wave height- vertical
distance between crest and
trough
Wavelength-horizontal
distance between adjacent
crests
Period- the time a wave
takes to move past a given
point
Wave Facts
 Water under a crest moves up and forward
 Water under a trough moves down and back
 Water particles move in circles as a wave passes
 Waves carry energy across sea surface but do not
transport water
Formation and Size of Waves
 Waves form as soon as the wind blows
 Faster and longer the wind blows the larger the wave
gets
 Size of waves generated by the wind depends on the
fetch (span of water over which the wind blows)
 As a wave approaches the shoreline it slows down and
“piles up” becoming high and steep making them fall
forward and break creating surf
Sea vs. Swell
 Seas- a wave that has a sharp peak and relatively flat
trough; found in the area where waves are generated
by the wind
 Swells- a wave with a flatter, rounded crest and trough;
found away from the area where waves are generated
by the wind
Sea
Swell
Wave Reinforcement
 Wave reinforcement- when the crests of two waves
collide and produce a higher wave
Wave Cancellation
 When a crest and a trough of two different waves
interact and cancel each other