Characteristics of All Wind-generated Waves

Deep Water Waves

Shallow Water Waves

Other Water Waves

Crest, trough, wavelength

Wave Height (H)

Wave Steepness

Period (T)

A wave in water depth > one-half wavelength

Sea vs. swell

What determines wave height?

Waves in water depth less than 1/20 of wavelength

Often associated with surf zone

Variety of surf depends on shape of bottom◦ Plunging◦ Spilling◦ Surging

spilling

plunging

surging

Deep water wave◦ Speed = 1.56T

Shallow water wave◦ Speed = 3.1 times square root of water depth

Bending of wave crests Waves approach beach at angle One part of crest reaches shallow water first

and slows down Waves become more parallel to shore

Wave Refraction

note distribution of wave energy most of energy strikes headlands causes erosion of headland, deposition in

bays coastal straightening occurs

disturbance of ocean floor speed greater than 700 km/hr wavelength greater than 200 km crests can exceed 30 m as reach shore

http://nctr.pmel.noaa.gov/