study guide ch 13-15

Which statement best explains the formation of seamounts?

They represent volcanoes situated over mantle plumes that have since moved away from their source of magma and subsided.

How is the height of an ocean wave measured?

Wave height is measured vertically from trough to crest.

What happens to irregular coastlines over time? Choose all that apply.

Wave refraction causes erosion of the headlands. Wave refraction causes deposition in the bays.

The surface area of Earth is composed of ____ percent ocean and _____ percent landmass.

71; 29

What is a tablemount?

A seamount that grew above sea level, experienced wave erosion, and is now inactive.

Why is deep-ocean circulation referred to as thermohaline? Choose all that apply.

Differences in salinity cause oceanic deep circulation. Differences in temperature cause oceanic deep circulation.

How are satellites able to map the ocean floor?

Due to gravity, ocean water is attracted to areas of high topography and away from areas of low topography on the sea floor, causing bulges and depressions on the ocean surface. Satellite radar can detect these changes in elevation.

What is the location and flow of the Gulf Stream?

The Gulf Stream flows northward along the east coast of North America.

Plates move apart at __________ boundaries, move together at __________ boundaries, and move side-by-side at __________ boundaries.

divergent/convergent/transform

Which sea floor resource-based industry is second in economic value only to the petroleum industry?

sand and gravel

Which of the following terms is a depositional feature on shorelines? Choose all that apply.

spit tombolo bar

What type of plate boundary is associated with deep-ocean trenches?

subduction zone

Which of the following oceans is the largest and deepest on Earth?

the Pacific Ocean

Which ocean current is the only one to completely circle Earth?

the West Wind Drift

What percent by weight of seawater consists of salts?

3.5 percent

What is the correct water depth for an echo travel time of 6 seconds? (For the purposes of this exercise, assume pressure and temperature effects on sound wave velocity are negligible.)

4500 meters

What is a seamount?

An active volcano that occurs along the crest of the mid-ocean ridge.

Which of the following mountain ranges are examples of continental arcs?

Andes and Cascades

What is the difference between a barrier reef and an atoll?

Barrier reefs surround an inactive volcano emerging above sea level, while atolls surround the previous location of a submerged volcano.

Which of the following statements is related to the recent increase in ocean acidity? Choose all that apply.

Carbon dioxide dissolves in ocean water. Acidification is caused by carbonic acid.

Which of the following statements about coral reefs and seamounts is most accurate?

Coral reefs at the ocean surface grow away from seamounts over time.

Which response best explains the absence of volcanoes and earthquakes at a passive continental margin?

Earthquakes and volcanoes are rare due to the distance from any active boundaries.

Which is the correct order of coral reef development near seamounts?

Fringing reef, barrier reef, atoll

Which of the following statements is true for ocean gyres? Choose all that apply.

Gyres are circular-moving currents. Gyres rotate clockwise in the Northern Hemisphere. Gyres occur at the ocean surface.

Where do coral reefs exist with sea mounts?

In tropical latitudes

Why are mid-ocean ridges elevated?

Lithosphere created at the ridge is hot.

How are marine organisms classified? Choose all that apply.

Marine organisms are classified by where they live. Marine organisms are classified by how they move.

Which of the following statements correctly describes productivity in temperate oceans?

Productivity in temperate oceans shows marked seasonal variation.

Why do coral reefs at the ocean surface grow away from seamounts over time?

Seamounts subside as tectonic plates move. Coral reefs grow away from the seamount in order to stay near the sunlight.

How do temperature and density vary with ocean depth at low latitudes? Choose all that apply.

Temperature decreases with depth near the equator. Density increases with depth near the equator.

What would happen to Earth if ocean floor were created at divergent boundaries at a faster rate than it is destroyed at convergent boundaries?

The Earth would increase in volume.

What is the relationship between the crust and lithosphere?

The crust is part of the lithosphere.

Why do all marine algae live near the ocean surface?

The sunlight at the ocean surface is needed for photosynthesis.

What is an emergent coast?

a coastal area that experiences an uplift of land or drop in sea level

Which feature would you expect to find at the mouth of a submarine canyon?

a deep sea fan

What is a volcanic arc?

a row of volcanoes that forms on the overriding plate near a subduction zone

What is a food chain?

a sequence through which energy is transferred from primary producer to top carnivore

What is the ideal ocean temperature for the growth of reef-building corals?

about 75 degrees Fahrenheit

Where is the youngest ocean floor found?

along the crest of mid-ocean ridges

What two factors influence an ocean region's photosynthetic activity? Choose all that apply.

amount of sunlight amount of nutrients

Ocean sediment composed of former diatoms falls under which category?

biogenous

Moving off the east coast of North America, identify the sequence of environments you would encounter as you move deeper into the Atlantic Ocean.

continental shelf, continental slope, continental rise, abyssal plain

Which is not one of the three broad zones describing the ocean floor?

continental slope

Which method is not a technique currently used by ocean scientists to map the topography of the ocean floor?

magnetometer

Which of the regions below are the three main provinces of the ocean floor? Choose all that apply.

mid-ocean ridge deep-ocean basin continental margin

Which geologic features are associated with divergent boundaries?

mid-ocean ridges and continental rift valleys

Complete this statement: Divergence is to moving away as convergence is to _______.

moving toward

Which geologic features are associated with convergent boundaries?

ocean trenches and volcanoes

Which of the following terms is an erosional feature on shorelines? Choose all that apply.

platform arch cliff

What processes decrease ocean salinity?

precipitation melting of sea ice runoff melting of icebergs

Which of the two following features compose a passive continental margin? Choose all that apply.

slope shelf

What two elements make up the most abundant seawater salt?

sodium, chlorine

What modern technique is used to measure the depth of the oceans?

sonar beneath the oceans

Which coast represents an active continental margin?

the west coast of South America

How many tidal patterns exist worldwide?

three

In the graph of echo sounding data that you created as part of this exercise, why is the vertical component of the graph exaggerated?

to compensate for the differences in the smaller vertical depths in the ocean relative to the greater horizontal distances measured

The deepest parts of the ocean are related to which tectonic feature?

trenches