12.2 Flashcards
Wave
Rhythmic movement that carries energy through matter or space
How are most waves generated
Wind moving over the surface of water
Anatomy of a wave (4 parts)
Crest, Trough, Wavelength, Wave height
Crest
The highest point of a wave
Trough
The lowest point of a wave
Wavelength
The horizontal distance between 2 consecutive crests
Wave height
The vertical distance between crest to trough
Wave base
Equal to half the wavelength
Wave height depends on three factors
Fetch, Wind duration, Wind speed
Fetch
The expanse of water that the wind blows across
wind duration
how long the wind blows uninterruptedly
wind speed
faster the wind speed, higher the waves
Breaker
a foamy mass of water that collapses onto the coastline
Tide
periodic rise and fall of sea level caused by the gravitational attraction among earth, the moon, and the sun
when is there high and low tide
when the water level is higher there is high tide and when the water level is lower there is low tide
tidal range
the distance in water level between high and low tide
how long is one daily tidal cycle
about 24 hours and 50 minutes
how many different tidal cycles are there
3
what are the 3 different tidal cycles
semidiurnal cycle, diurnal tidal cycle, mixed tidal cycle
semidiurnal cycle
see two high tides each day
mixed tidal cycle
see one pronounced and one smaller high tide per day
diurnal
see one high tide each day
what are the 2 special types of tides
spring and neap
spring tide
the earth, sun, and moon align to make a straight line
other details about spring tide
occur twice a month
the moon must be a new or full moon
increases the daily tidal range
neap tide
the earth, sun, and moon are right angles to each other
other details about neap tide
occur twice a month
the moon must be 1 quarter or 3 quarters full
decreases the daily tidal range
surface currents
wind driven movement of ocean water that primarily affects the upper few hundred meters of the ocean
gyre
closed circular ocean current systems
name the 5 major gyres
north atlantic, north pacific, south atlantic, south pacific, indian ocean
which way do the gyres move
clockwise in north hemisphere
counterclockwise in south hemisphere
upwelling
the upward motion of ocean water
density current
movement of ocean water that occurs
