waves Flashcards
what are ocean waves?
energy traveling along the interface between ocean and atmosphere
what is the crest?
top of the wave
what are troughs?
separate crests
what us the still water level?
halfway between crests and trough = level water would occupy if there were no waves
what is the wave height?
vertical distance between trough and crest
what is the wavelength?
horizontal distance between successive crests or successive troughs
what is the wave period?
time it takes one full wave - one wavelength - to lass a fixed position
the height, length, and period that are eventually achieved by a wave depend on 3 factors. what are they?
- wind speed
- wind duration - length of time wind has blown
- fetch - distance wind has traveled uninterrupted
what is circular orbital motion
-as a wave passes, each bit of water moves in a near-circle and returns to about where it started
-the energy contributed by the wind to the water is transmitted not only along the surface of the sea but also downward
-beneath the surface, the circular motion rapidly diminishes
what is the wave base?
depth equal to one-half the wavelength measured from still water level, here the movement of water particles becomes negligible
describe what happens when a wave breaks
-as a wave advances toward the shore, the wave bottom slows down, slightly faster waves farther out to sea catch up, decreasing the wavelength
-as speed and length of the wave decreases, the wave steadily grows higher
-critical point is reached when the wave is too steep to support itself, and the wave front collapses, or breaks causing water to advance up the shore
what is the surf?
turbulent water created by breaking waves
