Chapter 14 - Ocean Motions Flashcards
What occurs when seawater piles up, as in the middle of a gyre or against a shore?
Downwelling
What occurs when dense, cold, salty water moves from the abyssal regions to the surface?
Upwelling
What is the daily or twice-daily change in local sea level due to the moon’s gravity?
Lunar tide
What is set in motion by wind?
Surface current
What is a type of density current?
Thermohaline current
What is a lower-than-usual tide that occurs when the sun and moon are at a right angle to the earth?
Neap tide
What is a higher-than-usual tide that occurs at new moon or full moon?
Spring tide
True or False? The moon is the only astronomical body that affects Earth’s oceans.
False
What is a current that flows parallel to the shore?
Longshore current
What is formed by a wave that becomes unstable?
Breaker
What is the distance between the crest and trough of a wave?
Wave height
What is a narrow, fast current that gathers to flow offshore through gaps in offshore bars?
Rip current
What is the distance from one crest to another crest of a wave?
Wavelength
True or False? The very high tides that occur twice a month are caused by the sun, moon, and earth being arranged in a straight line.
True
True or False? In the center of an ocean gyre, the sea level is usually lower outside the gyre.
False
True or False? The greatest number of drownings is probably caused by longshore currents.
False
True or False? Twice each month, lower-than-usual tides called neap occur.
True
True or False? The Great Pacific Garbage Patch is the result of man’s carelessness and a strong oceanic turbidity.
False
True or False? A bulge current is a type of density current that carries a great amount of sediment and acts like an underwater mudslide.
False
True or False? The wavelength of a series of waves is the horizontal distance from the crest of one wave to the crest of the next wave.
True
True or False? The distance that blows over the water’s surface in one direction is the gyre of a wave caused by the wind.
False
True or False? A stack is a mass of rock that has been cut off from the mainland by erosion.
True
True or False? Density currents have a predictable path, but they move very slowly compared to the currents closer to the surface.
True
A(n) _____________ is defined as the alternating rise and fall of local sea level.
tide
A(n) __________________ is a higher-than-usual tide occurring twice a month.
spring
A _____________ is the lowest part of the wave.
trough
A ________________ is an unstable wave whose crest is falling forward.
breaker
A(n) _______________ is a spit with a sharp bend.
hook
A __________________ is a wave deposit that connects an island or a stack with the mainland.
tombolo
A ______________ is a circular flow of currents within an ocean basin.
gyre
A(n) _______________ is cold water rising to the surface.
upwelling
The major warm current located in the West Atlantic Ocean is the __________________.
Gulf Stream
