Deck 18: Restless Realm: Oceans and Coasts

Question 1

Compared with the continental lithosphere,the oceanic lithosphere is ________.

A) thicker
B) thinner
C) approximately the same thickness
D) exactly five times thinner

Answer 1

B

Question 2

The castle on the island of Mont Saint-Michel,France,can be accessed ________ a day during ________ tide,but ________ during neap tide.

A) twice; high; all day
B) once; low; all day
C) twice; low; never
D) once; high; never

Answer 2

C

Question 3

Rip currents ________ the shoreline.

A) flow directly toward
B) flow directly away from
C) flow parallel to
D) are not affected by

Answer 3

B

Question 4

Why is a spring tide so much higher than a normal high tide?

A) because the Sun is aligned with the moon
B) because the Moon is aligned with the Earth
C) because the Moon is directly over the North Pole
D) because the Sun is directly over the North Pole

Question 5

Waves ________.

A) refract so as to impact the shore in a nearly parallel manner
B) refract so as to impact the shore nearly perpendicular to the shoreline
C) reflect directly backward from the angle at which they approach the shoreline
D) are reflected off the shoreline but never refract

Question 6

What is the average percentage of dissolved salt in seawater?

A) 1.5%
B) 3.5%
C) 5.5%
D) 6.5%

Question 7

Which portion of the seafloor is most steeply sloped?

A) abyssal plains
B) continental shelves
C) continental slopes
D) continental rises

Question 8

You are running a sonar survey to map the bathymetry of an ocean basin.Using the following continuous sonar data giving the depth of the seafloor in meters,what feature have you just discovered? $$\begin{array} { | l | l | l | l | l | l | l | l | l | l | l | l | l | } \hline 3071 & 3011 & 2891 & 2846 & 2756 & 2577 & 2532 & 2487 & 2502 & 2577 & 2756 & 2921 & 3041 \\\hline\end{array}$$

A) an abyssal plain
B) a deep trench
C) a mid-ocean ridge
D) a continental shelf

Question 9

The shallowest portions of an ocean found along the margins of continents are the ________.

A) abyssal plains
B) continental rises
C) continental shelves
D) continental slopes

Question 10

The width of the intertidal zone depends on the __________.

A) tidal flat
B) tidal bore
C) tidal range
D) ebb tide

Question 11

Approximately what percentage of the Earth's surface is covered with ocean water?

A) 30%
B) 50%
C) 70%
D) 85%

Question 12

Compared with the continental crust,the oceanic crust is ________.

A) denser
B) less dense
C) about the same density
D) about half as dense

Question 13

Why is the surface salinity in the tropics so much higher than that of the equator or high latitudes?

A) There is a higher evaporation rate in the tropics.
B) There is a higher rate of precipitation in the tropics.
C) There are more continents in the tropics,and thus more sediment weathered.
D) There is a large influx of freshwater from rivers along the equator.

Question 14

You have been given the extraordinary opportunity to take Alvin (a submersible)down into the Atlantic Ocean to examine how the seafloor sediments have changed throughout geologic history.Which of the following locations would yield the most information?

A) down along the Mid-Atlantic Ridge
B) any spot in the abyssal plain
C) just off the coast of Iceland
D) just off the coast of North America

Question 15

At the equatorial ocean basins,sea surface temperatures may reach 25°C or greater.What is the range of temperatures for the seafloor,approximately 4-5 km below?

A) slightly warmer (33°C)
B) about room temperature (25°C)
C) cool (10°C-15°C)
D) near freezing (1°C-2°C)

Question 16

Using the figure below,which of the following lists correctly identifies the seafloor landforms G,C,and F?

A) G = abyssal plain,C = mid-ocean ridge,F = trench
B) G = abyssal plain,C = continental rise,F = trench
C) G = continental shelf,C = abyssal plain,F = continental rise
D) G = abyssal plain,C = volcanic arc,F = trench

Question 17

The sea surface salinity is ________ at the mouth of the Amazon River and ________ in the Dead Sea.

A) low; low
B) high; low
C) low; high
D) high; high

Question 18

Longshore currents ________ the shoreline.

A) flow directly toward
B) flow directly away from
C) flow parallel to
D) are not affected by

Question 19

High tide during a full moon will be ________.

A) the same as normal
B) lower than normal
C) higher than normal
D) reversed relative to normal

Question 20

The form and topography (depth profile)of the ocean floor is termed ________.

A) orogeny
B) bathymetry
C) sonar
D) marine geology

Question 21

Barrier islands are constantly moving in the direction of ________.

A) the longshore drift
B) the open ocean
C) downwelling
D) the Coriolis effect

Question 22

What will eventually happen to the headlands in the figure below?

A) They will join as the bays in between fill with sediment.
B) They will become a straight line of cliffs as rock is eroded away.
C) They will remain as they are for millions of years.
D) The sea will submerge them as the terrace is uplifted.

Question 23

Which of the following features is characteristic of a rocky coast?

A) sand spits
B) sea stacks
C) lagoons
D) accretionary prisms

Question 24

Swamps and marshes are examples of __________.

A) estuaries
B) coastal wetlands
C) fjords
D) swashes

Question 25

Major oceanic surface currents travel ________.

A) parallel to the prevailing wind direction in a region
B) in direct opposition to prevailing winds as a result of the Coriolis effect
C) at an angle to prevailing winds as a result of the Coriolis effect
D) at an angle to prevailing winds as a result of the Doppler effect

Question 26

Surface currents flow __________ in the Northern Hemisphere and __________ in the Southern Hemisphere.

A) counterclockwise; clockwise
B) upward; downward
C) clockwise; counterclockwise
D) equatorward; poleward

Question 27

The Coriolis effect causes the apparent deflection of currents as a result of

A) changes in wind speed.
B) the rotation of the Earth.
C) changes in ocean currents.
D) the location of the Moon.

Question 28

When the sea level rises,an ocean may invade a river valley,producing a nearshore body of water of mixed and variable salinity termed a(n)________.

A) atoll
B) lagoon
C) estuary
D) jetty

Question 29

The major surface currents on Earth that display a circle-like path and follow the ocean basin margins are known as __________.

A) eddies
B) lochs
C) pools
D) gyres

Question 30

In the figure below,which way is the wave moving?

A) to the right
B) to the left
C) back and forth
D) The wave is stationary.

Question 31

Thermohaline circulation carries ________ water from the poles to the equator,where the water becomes ________.

A) warm; cold
B) cold; warm
C) low density; more dense
D) low density; more salty

Question 32

In the figure below,which letters represent the wave height and wavelength?

A) B and E
B) E and D
C) C and E
D) B and C

Question 33

If a beach is in an east-west orientation and the waves are approaching the shore from the southeast,in which direction will the longshore drift be?

A) northern
B) western
C) southern
D) eastern

Question 34

A(n)__________ is a vegetated,flat-lying stretch of coast that floods at high tide,becomes particularly exposed at low tide,and does not feel the impact of strong waves.

A) marine terrace
B) coral reef
C) coastal wetland
D) estuary

Question 35

Because of wave refraction,erosion along an irregular coastline is ________.

A) even along the length of the coast
B) greatest along headlands
C) greatest in bays
D) the same as it would be along a regular coastline

Question 36

Which of the following is the BEST example of an organic coast?

A) gently sloping,well-developed beach
B) wave-cut platform
C) shoreline that has just received beach nourishment
D) shallow coral reef

Question 37

A coastline characterized by steep-sided cliffs and associated with an active margin is likely to be __________.

A) accretionary
B) submergent
C) passive
D) emergent

Question 38

In the figure below,which letters represent the crest and trough?

A) A and B
B) E and D
C) C and D
D) C and B

Question 39

The density of seawater increases with ________ temperature and ________ salinity.

A) increasing; increasing
B) decreasing; increasing
C) increasing; decreasing
D) decreasing; decreasing

Question 40

A coral reef would MOST likely be found

A) in an expansive,warm-water tropical tidal flat.
B) in clear,shallow waters at high latitudes.
C) in the shallow waters surrounding a tropical volcanic island.
D) along the coasts of active margins.

Question 41

A coast that grows seaward as a result of regular sedimentation is a(n)__________

A) active continental margin.
B) erosional coast.
C) accretionary coast.
D) coastal plain.

Question 42

Why is it a bad idea to build on barrier islands?

Question 43

Which of the following scenarios is most likely to result in an emergent coast?

A) global sea level rise
B) uplift associated with active margin tectonics
C) subsidence of the shoreline caused by near-shore removal of groundwater
D) the formation of a near-shore coral reef

Question 44

The process of reef bleaching occurs when __________.

A) reefs lose their color and die in response to warming of seawater
B) reefs lose their color following sedimentation due to a large storm
C) reefs are exposed to too much sunlight
D) overfishing causes a decrease in species diversity

Question 45

Sea level is currently rising at 3.3 mm/year,and scientists predict that global warming could cause a rise in sea level of 7 m if left unabated.How long will it take the sea to rise 7 m at the current rate?

A) 2,121 years
B) 0.0004 year
C) 2.121 years
D) 0.47 year

Question 46

Draw a representation of the motion of an ocean wave in cross-section.Your illustration should include labels for the following: amplitude,wavelength,wave height,crest,trough,and directional arrows.

Question 47

Define the flow of the Ekman transport and explain its process.

Question 48

Structures-like jetties,groins,and breakwaters-that are designed to prevent beach erosion __________.

A) are permanent solutions that protect erosional beaches
B) must be built in conjunction with beach nourishment
C) are a temporary solution that decreases the rate of beach erosion
D) have the added benefit of allowing organic coasts to develop

Question 49

Notice the newly constructed seawall in the illustration below.The most likely outcome of its construction is that the seawall will __________.

A) permanently protect the home from beach erosion
B) increase sediment production on the beach,decreasing the rate of erosion
C) deter biological activity that might compromise the integrity of the cliff
D) temporarily protect the cliff from beach erosion

Question 50

Which type of coastline would most likely contain estuaries or fjords?

A) a subductive coastline
B) an emergent coastline
C) a submergent coastline
D) a divergent coastline

Question 51

Along beaches,groins have ________.

A) solved the problem of beach drift
B) increased erosion rates immediately up-current from the groin
C) increased erosion rates immediately down-current from the groin
D) increased depositional rates immediately down-current from the groin

Question 52

Label the landforms of ocean basins shown in the image below using the following word bank.(Note: not all of the words will be used.)

Question 53

How is an erosional coast different from an accretionary coast?

Question 54

If the Earth's solid surface was smooth and completely submerged beneath the ocean,each location would experience two tides a day and the tidal reach would depend on the position of the location relative to the highest part of the bulge.This is not the case.Describe three factors,aside from the tide-generating force,that affect the timing and magnitude of tides.

Question 55

Why do tides occur? What is the driving force and what factors contribute to this force?

Question 56

Describe one way humans have tried to mitigate beach erosion.What were the short-term and long-term results of this action?

Question 57

The Florida coast is an example of a(n): ________.

A) emergent coast
B) submergent coast
C) continental slope
D) abyssal plain

Question 58

Contrast emergent and submergent coasts.List at least one reason why coasts may become emergent or submergent.

Question 59

What is the average salinity of the oceans? How does ocean salinity vary? What factors are responsible for higher and lower salinity?

Question 60

Which of the following is true of beach nourishment as a solution to coastal erosion?

A) It is a permanent solution that will protect an erosional beach.
B) The flux of sediment from beach nourishment will change a beach from erosional to accretionary.
C) It is a temporary,but inexpensive,solution to coastal erosion.
D) It is costly and may only provide a temporary solution.