GEOL 1121 - HW18

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

a submergent coastline

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

are a temporary solution that decreases the rate of beach erosion

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

denser

Rip currents ________ the shoreline.

flow directly away from

Barrier islands are constantly moving in the direction of ________.

the longshore drift

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?

2121 years

What is the average percentage of dissolved salt in seawater?

3.5%

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

70%

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

B and E

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

C and D

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

G= abyssal plain, C = mid-ocean ridge, F = trench

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

It is costly and may only provide a temporary solution.

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

There is a higher evaporation rate in the tropics.

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

They will become a straight line of cliffs as rock is eroded away.

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?

a mid-ocean ridge

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

accretionary coast.

Major oceanic surface currents travel ________.

at an angle to prevailing winds as a result of the Coriolis effect

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

bathymetry

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

because the Sun is aligned with the moon

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

clockwise; counterclockwise

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.

coastal wetlands

Swamps and marshes are examples of __________.

coastal wetlands

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

cold; warm

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

continental shelves

Which portion of the seafloor is most steeply sloped?

continental slopes

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

decreasing; increasing

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

emergent

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

emergent coast

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) ________.

estuary

Longshore currents ________ the shoreline.

flow parallel to

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

greatest along headlands

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

gyres

High tide during a full moon will be ________.

higher than normal

A coral reef would MOST likely be found

in the shallow waters surrounding a tropical volcanic island.

are a temporary solution that decreases the rate of beach erosion

increased erosion rates immediately down-current from the groin

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?

just off the coast of North America

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

low; high

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?

near freezing (1°C−2°C)

The process of reef bleaching occurs when __________.

reefs lose their color and die in response to warming of seawater

Waves ________.

refract so as to impact the shore in a nearly parallel manner

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

sea stacks

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

shallow coral reef

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

temporarily protect the cliff from beach erosion

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

the rotation of the earth

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

thinner

The width of the intertidal zone depends on the __________.

tidal range

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

to the right

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

twice; low; never

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

uplift associated with active margin tectonics

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?

western