OCE1001 Chapter 3

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern. Seamounts Metal sulfide deposits Trenches Pillow basalts Rift valley

Trenches

Which of the following best describes turbidity currents? Turbid water that kills coral and other photosynthesizing creatures by blocking light Muddy water brought to the ocean by rivers and streams to form a delta Underwater avalanches of muddy water mixed with rocks and other debris Riftvalley sediments found within the depression at midocean ridges Metalrich deposits that form on the flanks of submarine volcanoes

Underwater avalanches of muddy water mixed with rocks and other debris

What percent of Earth's volcanic activity, each year, takes place on the seafloor? 70% 80% 75% 85% 65%

85%

Active continental margins are characterized by which of the following? Broad continental shelves No sediment accumulation Deep-sea trenches Shallow coastal waters Sparse earthquake activity

Deep-sea trenches

Rocks like the ones shown in the photo most likely formed at which of the following tectonic settings? Convergent plate boundary Divergent plate boundary Intraplate setting Transform plate boundary

Divergent plate boundary

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern. Active margin Transform active margin Convergent active margin Continental margin Rift valley

Rift valley

Older lithosphere is destroyed in association with: fracture zones. spreading centers. hydrothermal vents. deep-sea trenches. mid-ocean ridges.

deep-sea trenches.

The majority of ocean trenches are associated with ___________. Choose all that apply. the Pacific Ring of Fire very deep ocean water depths narrow or no continental margins the mid-ocean ridge subduction zones and associated faults

the Pacific Ring of Fire very deep ocean water depths narrow or no continental margins volcanic arcs and active continental margins subduction zones and associated faults

The greatest proportion of Earth's surface lies in this elevation/depth interval. 3,000 4,000 m below sea level 1,000 2,000 m above sea level 5,000 6,000 m below sea level 0 1,000 m above sea level 4,000 5,000 m below sea level

4,000-5,000 m below sea level

A ship's fathometer (an echo sounder) transmits a sound pulse and records the return of an echo 7.4 seconds later. If the speed of sound in water is 1,500 m/second, what is the water depth in meters? 5,550 meters 11,100 meters 3,000 meters 7,400 meters 4,550 meters

5,500 meters

Characteristics of passive continental margins include which of the following? Deep-sea trenches Thin sediment accumulation Volcanic and earthquake activity Chains of islands Broad continental shelves

Broad continental shelves

Passive margins are usually produced over geologic time by which of the following? Continental rifting and continued sea floor spreading Subduction of oceanic crust and submarine volcanic activity Hot spot volcanism forming a chain of island and seamounts Transform faulting along a continental margin or a mid-ocean ridge The closing of an ancient sea to form a salt lake

Continental rifting and continued sea floor spreading

Where does the deepocean basin begin along a passive continental margin? ANSWER: Continental shelf Shoreline Abyssal plain Continental rise Continental slope

Continental slope

Which of the following features is related to transform faults along midocean ridges? Continental shelf Submarine canyon Continental slope Fracture zone Continental rise

Fracture zone

The distinctive type of sedimentary layering that has largest particles on the bottom and smallest particles on the top, with intermediate sized particles in the middle, is called which of the following? Sandstone Layering Nonconformities Turbidity Currents Graded beading Suspension Deposits

Graded beading

What is a linear sea floor feature that is seismically inactive, occurs beyond offset mid-ocean ridge segments, and the relative movement between two points on either side of the feature is in the same direction? Seaknolls Transform fault Nemataths Guyots Fracture zone

Guyots

Which of the following techniques used to determine ocean bathymetry is illustrated in the image? Magnetometer Multibeam Sonar Seismic Reflection Seismic Relfection Side-Scan Sonar Souding

Multibeam Sonar

Of the following statements about mapping the ocean floor, which is/are true? Nearly 80% of the ocean floor has been accurately mapped using sonar from ships. Only about 20% of the sea floor has been accurately mapped in detail. Satellites can be used to determine the structure and composition of the sea floor. Multibeam surveys from ships produce very detailed maps of the sea floor. Measurements of sea surface elevation by satellites are used to produce maps of the sea floor.

Only about 20% of the sea floor has been accurately mapped in detail. Multibeam surveys from ships produce very detailed maps of the sea floor. Measurements of sea surface elevation by satellites are used to produce maps of sea floor.

Tamu Massif, the largest single volcano on Earth occurs in which of the following oceans? Atlantic Ocean Arctic Ocean Pacific Ocean Indian Ocean Southern Ocean

Pacific Ocean

Which of the following techniques used to determine ocean bathymetry is illustrated in the image? Magnetometer Multibeam Sonar Seismic Reflection Sidescan Sonar Sounding

Side-scan sonar

The first recorded attempt to measure the ocean's depth was conducted using which of the following techniques? Magnetometer Seismic Reflection Multibeam Sonar Sounding Side-scan Sonar

Sounding

Which of the following is the predominant process that forms the thick blanket of sediment on abyssal plains the deepocean floor? Precipitation Black smokers Suspension setting Undersea streams Melting icebergs

Suspension setting

Judge the following sentence according to the criteria given below: Multibeam SONAR systems have resolution limitations in deep water BECAUSE beams of sound spread out with depth. The assertion and the reason are both correct, and the reason is valid. The assertion and the reason are both correct, but the reason is invalid. The assertion is correct, but the reason is incorrect. The assertion is incorrect, but the reason is correct. Both the assertion and the reason are incorrect.

The assertion and the reason are both correct, but the reason is valid.

Judge the following sentence according to the criteria given below: Few abyssal plains are located in the Pacific Ocean BECAUSE turbidity currents only occur along passive continental margins. The assertion and the reason are both correct, and the reason is valid. The assertion and the reason are both correct, but the reason is invalid. The assertion is correct, but the reason is incorrect. The assertion is incorrect, but the reason is correct. Both the assertion and the reason are incorrect.

The assertion is correct, but the reason is incorrect.

Judge the following sentence according to the criteria given below: The Pacific Ring of Fire is home to the majority of Earth's active volcanoes and large earthquakes BECAUSE of the prevalence of divergent plate boundaries along the Pacific Rim. The assertion and the reason are both correct, and the reason is valid. The assertion and the reason are both correct, but the reason is invalid. The assertion is correct, but the reason is incorrect. The assertion is incorrect, but the reason is correct. Both the assertion and the reason are incorrect.

The assertion is correct, but the reason is incorrect.

Of the following statements about Earth's hypsographic curve, which is/are true? Choose all that apply. The hypsographic curve shows that a majority of the exposed land is below 1 kilometer in elevation. The hypsographic curve shows the percentage of Earth's surface area that is covered by ocean waters. The hypsographic curve shows that a majority of the ocean floor is more than 4 kilometers deep. The hypsographic curve shows that the average depth of the ocean is about four times the average height of the continents. The hypsographic curve shows that the volume of water in the oceans is greater than the volume of water in lakes and glaciers.

The hypsographic curve shows that a majority of the exposed land is below 1 kilometer in elevation. The hypsographic curve shows the percentage of Earth's surface area that is covered by ocean waters. The hypsographic curve shows that a majority of the ocean floor is more than 4 kilometers deep. The hypsographic curve shows that the average depth of the ocean is about four times the average height of the continents.

Which part of Earth's cumulative hypsographic curve includes the mid-ocean ridges? The gentle slope above sea level The long and flat part below sea level The shallowest slope below sea level The steep deepest part below sea level The steep segment above sea level

The shallowest slope below sea level

Of following items, which is/are associated with a passive continental margin? volcanic eruptions and pillow lavas a continental rise a wide continental shelf a deep-ocean trench an abundance of earthquake activity

a continental rise a wide continental shelf

The average slope of the continental shelf is approximately _____________. greater than five degrees a tenth of a degree two to five degrees one-half to one degree one to two degrees

a tenth of a degree

Volcanic features on the ocean floor that are less than 1,000 meters (0.6 miles) tall are called: abyssal hills or seaknolls oceanic trenches oceanic ridges seamounts tablemounts

abyssal hills or seaknolls

Extending from the base of the continental rises into the deepocean basins are flat depositional surfaces called: tablemounts abyssal plains continental shelves abyssal hills continental slopes

abyssal plains

Which of the following feature(s) is/are associated with the mid-ocean ridge? Choose all that apply. basalt volcanism and pillow lavas a central rift valley volcanoes thick layers of sediment a trench hydrothermal vents

basalt volcanism and pillow lavas a central rift valley volcanoes volcanoes hydrothermal vents

The measurement of ocean depth and the charting of seafloor topography is called __________. bathymetry tomography navigation cartography hydrology

bathymetry

Volcanic peaks that are below sea level but rise more than 1 kilometer above the deepocean floor and have a flattened top are called ________. guyots nemataths seaknolls seamounts islands

guyots

The direction of motion along a seafloor transform fault is: associated with turbidity currents. in the same direction as the plates are spreading. In the same direction as the ridge offsets. Influenced by underwater boundary currents. Perpendicular to the direction of plate movement.

in the same direction as the plates are spreading.

The island of Java is an example of a volcanic island associated with volcanic activity at a ________. island arc mid-ocean ridge rift valley hotspot transform fault

island arc

What processes influence the shape and features of continental shelves? Choose all that apply. large fluctuations in sea level over geologic time trench formation at convergent boundaries major climate changes, such as ice ages tectonic activity produced by offshore faults the creation of pillow lavas along the mid-ocean ridge

large fluctuations in sea level over geologic time trench formation at convergent boundaries major climate changes, such as ice ages tectonic activity produced by offshore faults

New lithosphere is produced in association with: oceanic ridges deep-sea trenches hydrothermal vents fracture zones transform faults

oceanic ridges

Along the margins of the Pacific are found most of Earth's: tablemounts oceanic ridges oceanic trenches seamounts abyssal hills or seaknolls

oceanic trenches

With respect to mid-ocean ridges, transform faults are: associated with hydrothermal vents. located in submarine canyons. perpendicular to the ridge axis. parallel to the rift.

perpendicular to the ridge axis.

Most large ocean floor features owe their origins to ________. extreme pressure at depth biological activity ocean current activity plate tectonic processes erosion and weathering

plate tectonic processes

Volcanic peaks on the deepocean floor with conical tops are called: tablemounts oceanic trenches submarine canyons oceanic ridges seamounts

seamounts

In comparison with other ocean basins, major sedimentary features such as continental rises and abyssal plains are relatively rare in the Pacific. The primary reason for their scarcity in the Pacific is that __________. the Pacific Ocean is too large for those features to form the numerous volcanoes of the Pacific rim and islands prevent normal sedimentation rivers do not carry much sediment into the Pacific turbidity currents are rare in the Pacific, so little sediment is carried down the continental slopes sediment is trapped within the trenches of the convergent plate boundaries ringing the Pacific

sediment is trapped within the trenches of the convergent plate boundaries ringing the Pacific.

The correct order of seafloor features from the coast to the midocean ridge is: abyssal plain, rise, slope, shelf. abyssal plain, shelf, slope, rise. rise, abyssal plain, slope, shelf, slope, rise, abyssal plain. slope, rise, shelf, abyssal plain.

shelf, slope, rise, abyssal plain

The method that is used most frequently to investigate sediment and rock layers of the sea floor is: sound waves (specifically seismic reflecting profiling). light waves. drilling. direct observation. satellite observation.

sound waves

Warm water (From 30°C to 350°C) hydrothermal vents form: Black smokers white smokers abyssal hills turbidity currents cold seeps

white smokers

Satellites are used to map the ocean floor because ________. they are affected by surface weather they are inexpensive to build and launch the shape of the ocean surface reflects large features on the seafloor they can't cover areas where ships have not produced surveys they can only "see" small areas of the seafloor at one time.

the shape of the ocean surface reflects large features on the seafloor

Of the following techniques, which one(s) can be used to map the sea floor? using satellites to measure the sea surface measuring seawater clarity recording many depths using a long cable direct visitation of the sea floor sending sound through water (sonar)

using satellites to measure the sea surface recording many depths using a long cable direct visitation of the sea floor sending sound through water sending sound through water (sonar)

Seamounts and abyssal hills are ________ in origin. sedimentary metamorphic seismic volcanic

volcanic