moon
has the greatest influence over the tides
2 lows 2 highs
how many tides do most coasts experience in a typical 24 hour period
What causes the high tides that occur twice a month?
the sun, moon, and earth being arranged in a straight line
Antarctic Circumpolar Current
includes the southern portions of the Pacific, Atlantic, and Indian Ocean gyres. Also transfers surface and subsurface currents between these main basins as it flows past Africa, South America, and Australia.
Canary Current
the major warm current located in the West Atlantic Ocean
Ekman spiral
combines the effects of the Coriolis effect, current speed, and water depth to produce the direction of a current
plankton, European eels, humpback whales, blue sharks, sea turtle, sea birds
sea life that is thought to take advantage of ocean currents in their efforts to move about
higher than outside the gyre
in the center of a ocean gyre, the sea level is usually ____.
more oxygen but less nutrients
water that is forced down by downwelling typically has _____ than surrounding waters.
prevailing winds
has the least effect on subsurface currents
2 things applying to thermohaline currents
density currents
subsurface currents
wave base
the deepest depth below the ocean's surface that is affected by the wave's passage
wave period
most directly related to wave speed
rip currents
cause the greatest amount a drownings per year
a strong, narrow surface current that carries water from the shore to the sea
neap tides
occur twice each month; lower-than-usual tides
Great Pacific Garbage Patch
the result of man's carelessness and a strong oceanic gyre
turbidity current
type of density current that carries a great amount of sediment and acts like an underwater mudslide
wavelength
the horizontal distance from the crest of one wave to the crest of the next wave
fetch
distance that wind blows over the water's surface in one direction
stack
a mass of rock that has been cut off from the mainland by erosion
Why is upwelling often associated with very productive fisheries?
Upwelling pulls up nutrients that support phytoplankton, the basis of the marine food chain
Why is it inaccurate to call a tsunami wave a tidal wave?
Tsunami waves are caused by large earthquakes. The regular changes in sea levels caused by the gravitational pull of the sun and the moon are true tidal waves.
Why are groins sometimes constructed along coastlines?
Groins disrupt longshore currents, thus reducing beach erosion
breaker
an unstable wave whose crest is falling forward
gyre
a circular flow of currents within an ocean basin
hook
a pit with a harp bend
longshore current
a current resulting from waves breaking at an angle to the shore
spring
a higher-than-usual tide occurring twice a month
tides
the alternating rise and fall of local sea level
tombolo
a wave deposit that connects an island or a stack with the mainland
trough
the lowest part of a wave
upwelling
cold water rising to the surface
power plants
designed to harness the power of tidal changes
are fairly small
currents
are affected by the rotation of the earth
Cold ocean currents
along a coast can dry the air so much that a desert forms
longest waves
greatest speed
List at least 3 things besides the position of the sun and moon that can affect the height and times of the tides.
1. the shape of the coastline
2. width of the continental shelf
3. the size and depth of the ocean basin
4. position of the moon relative to the Equator
5. a hurricane can also push water forward, causing dangerously high tides, especially if it occurs du
Describe density currents and the major factors that cause them to develop and flow
Water that is higher in salinity is also denser, causing it to sink below less dense water. Cooler water is also denser than warmer water. AS a result, these factors cause the coldest, densest water to move to the sea floor where gravity causes it to foll