Waves Pt 2 Flashcards
What happens when the wave “feels bottom”?
slows, and the accompanying** reduction** in the **wavelength results **in increased
height and steepness as the wave’s energy is condensed in a
smaller water volume.
How do we calculate the steepness of the wave?
height/wavelength
(h/L)
What happens to hight and wavelength when steepness increases?
Height Increases
Wavelength decreases
What are breakers?
**shallow **water waves that become too steep at surface so they collapse
How do breakers work?
particles at the wave’s crest move faster **toward **the shore resulting in the **curling **of the crest and the eventual breaking of the wave
What happens if the wave steepness exceeds 1:7?
wave becomes** too steep **and the wave breaks
What are the types of breaker waves?
Spilling
Plunging
Surging
What are spilling breakers?
-lasts long and** continually breaking** and slowly loosing energy across the surf zone
-Most common
-Flat bottom
What are plunging breakers?
-entire wave front steepens, curls and **collapses, relesing energy all at once.
-Occurs** in** steep bottoms**
What are surging?
-Don’t break because it never reaches a critical wave **steepness.
(H/L)=1:7
-diminishes** in size and** looses momentum** as water
rushes up beach face
-occurs in** steep bottoms**
What are stokes drift?
mass** transport** of water forward in
the direction of wave energy** movement.**
How do stoke drifts occur?
Negligible in open ocean
Slow movement against coast causes nearshore
currents
What is the general speed of a wave equation?
Celerity(Speed)=wavelength/time
What happens to wavelgth as celerity is reduced
Wavelength is shortened
What are shallow wave speed infuenced by?
influenced more by** depth**
than wavelength
What are deep water waves influecnced by?
influenced by wavelength than depth
What is dispersion?
Sorting of free waves as they move because** long period waves travel faster** than short period waves in deep water.
What is deep water group speed?
when a group
of waves travels if generated by the same source in
deep water
What is deepwater group speed equation?
Group wave speed=individual wave speed/2
What is the shallow water speed equation?
celerity=3.13 * Sqare root of depth
What is the deep water speed equation?
celerity=1.56*period