oceanography chapter 3
Which of the following is the predominant process that forms the thick blanket of sediment on abyssal plains the deep-ocean floor?
Suspension settling
What is a linear sea floor feature that is seismically active, occurs between offset mid-ocean ridge segments, and the relative movement between two points on either side of the feature is in the opposite direction?
Transform fault
Satellites use microwave beams to measure sea level to an accuracy of four
centimeters
Directly seaward of the continental shelf is a more steeply sloping region called the
continental slope
Older lithosphere is destroyed in association with
deep-sea trenches
A tablemount is another name for a(n)
guyot
The Big Island of Hawaii is an example of a volcanic island associated with volcanic activity at a
hotspot
The direction of motion along a seafloor transform fault is
in the same direction as the plates are spreading
Where are the deepest portions of the world's oceans found?
At convergent plate boundaries
Passive margins are usually produced over geologic time by which of the following?
Continental rifting and continued sea floor spreading
The relief in which of the following regions is similar to that found in mountain ranges on the continents?
Continental slope
Where does the deep-ocean basin begin along a passive continental margin?
Continental slope
Which of the following is an example of a passive continental margin?
East Coast of the United States
Which of the following is the standard unit of ocean depth?
Fathom
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?
Fracture zone
Which of the following features is related to transform faults along mid-ocean ridges?
Fracture zone
Is a linear sea floor feature that has the following properties a transform fault, a fracture zone, or neither? It is seismically active, it occurs between offset mid-ocean ridge segments, and the relative movement between two points on either side of the feature is in the same direction.
Neither
Is a linear sea floor feature that has the following properties a transform fault, a fracture zone, or neither? It is seismically inactive, it occurs between offset mid-ocean ridge segments, and the relative movement between two points on either side of the feature is in the same direction.
Neither
Deep-ocean trenches and volcanic arcs result from the collision of two plates at convergent plate boundaries and mostly occur along the margins of which of the following oceans?
Pacific Ocean
Tamu Massif, the largest single volcano on Earth occurs in which of the following oceans?
Pacific Ocean
Which of the following is the predominant process that forms the metallic minerals in and around black smokers?
Precipitation
Oceanographers who want to know about ocean structure beneath the sea floor use which of the following techniques?
Seismic Reflection
The first recorded attempt to measure the ocean's depth was conducted using which of the following techniques?
Sounding
Which of the following best describes turbidity currents?
Underwater avalanches of muddy water mixed with rocks and other debris
The average slope of the continental shelf is approximately
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
Extending from the base of the continental rises into the deep-ocean basins are flat depositional surfaces called
abyssal plains
Oceanic ridges and rises result from seafloor spreading along
divergent plate boundaries
Submarine canyons were most likely formed by
erosion by turbidity currents
Volcanic peaks that are below sea level but rise more than 1 kilometer above the deep-ocean floor and have a flattened top are called ________.
guyots
The two relatively flat areas on the hypsographic curve represent
interior continental areas and abyssal plains on the ocean floor
The island of Honshu is an example of a volcanic island associated with volcanic activity at a
island arc
The island of Java is an example of a volcanic island associated with volcanic activity at a
island arc
Ascension Island is an example of a volcanic island associated with volcanic activity at a
mid-ocean ridge
New lithosphere is produced in association with
oceanic ridges
Segments of the oceanic ridge system that are gentler and less rugged in slope due to faster rates of seafloor spreading are called
oceanic rises
The instrument that emits a high-frequency sound beam to measure the depth of the ocean developed in the 1950s is the
precision-depth recorder (PDR)
Volcanic features on the ocean floor that are less than 1000 meters tall are called
seaknolls
Volcanic peaks on the deep-ocean floor with conical tops are called
seamounts
Volcanic peaks that are below sea level but rise more than 1 kilometer above the deep-ocean floor and have a pointy top like an upside-down ice cream cone are called ________.
seamounts
Underwater avalanches of muddy water mixed with rocks and debris are
turbidity currents
All true oceanic islands are ________ in origin.
volcanic
Seamounts and abyssal hills are ________ in origin.
volcanic
Worldwide, scientists estimate that there are about 125,000 known seamounts, many of which originated at ________ centers.
volcanic
Warm-water (From 30°C to 350°C) hydrothermal vents form
white smokers
Along the margins of the Pacific are found most of Earth's
oceanic trenches
With respect to mid-ocean ridges, transform faults are
perpendicular to the ridge axis
What percent of Earth's volcanic activity, each year, takes place on the seafloor?
85%
How many volcanic peaks are known to exist on the Pacific sea floor?
> 20,000
The average slope of the continental shelf is similar to the slope of which of the following?
A large parking lot
Characteristics of passive continental margins include which of the following?
Broad continental shelves
Active continental margins are characterized by which of the following?
Deep-sea trenches
Which part of Earth's cumulative hypsographic curve includes the continental shelves of passive margins?
The shallowest slope below sea level
Which part of Earth's cumulative hypsographic curve includes the mid-ocean ridges?
The shallowest slope below sea level
Which part of Earth's cumulative hypsographic curve includes linear scars in the ocean floor, caused by the collision of two plates along convergent plate margins?
The steep deepest part below sea level
The correct order of seafloor features from the coast to the mid-ocean ridge is
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)
Relatively few abyssal plains are located in the Pacific Ocean due to
the presence of convergent active margins
Satellites are used to map the ocean floor because
the shape of the ocean surface reflects large features on the seafloor