Oceanography Ch 1-3
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? A) Fracture zone B) Nemataths C) Guyots D) Transform fault E) Seaknolls
A) Fracture zone
Submarine canyons were most likely formed by: A) erosion by turbidity currents. B) scouring by glaciers during the last ice age. C) erosion by major rivers in the past. D) earthquake activity. E) deposition of terrestrial sediment.
A) erosion by turbidity currents.
The island of Java is an example of a volcanic island associated with volcanic activity at a ________. A) island arc B) transform fault C) mid-ocean ridge D) hotspot E) rift valley
A) island arc
Relatively few abyssal plains are located in the Pacific Ocean due to: A) the presence of convergent active margins. B) its smaller size compared to other ocean basins. C) the presence of seamounts. D) the absence of convergent active margins. E) all of the above.
A) the presence of convergent active margins.
C. submarine canyon
A. abyssal hill B. abyssal plain C. submarine canyon D. seamount E. tablemount
B. deep focus earthquake
A. black smoker B. deep focus earthquake C. hydrothermal vent D. rift valley E. white smoker
E. rift valley
A. continental margin B. active margin C. convergent active margin D. transform active margin E. rift valley
Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Please identify the word and/or phrase that does NOT fit the pattern. Enter only the letter of the answer (caps, no period, and not the full entry) in the field below. A. passive margin B. ocean trench C. volcanic arc D. island arc E. continental arc
A. passive margin
D. seaknoll
A. rift valley B. oceanic ridge C. oceanic rise D. seaknoll E. seafloor spreading
D. abyssal plains
A. turbidity currents B. graded bedding C. turbidite deposits D. abyssal plains E. deep-sea fans
The majority of ocean trenches are associated with ___________. narrow or no continental shelves very deep ocean water depths subduction zones and associated faults the mid-ocean ridge volcanic arcs and active continental margins the Pacific Ring of Fire
ALL BUT MID OCEAN RIDGE
Directly seaward of the continental shelf is a more steeply sloping region called the: A) mid-ocean ridge. B) continental rise. C) continental slope. D) abyssal plain. E) trench.
C) continental slope.
Older lithosphere is destroyed in association with: A) hydrothermal vents. B) mid-ocean ridges. C) deep-sea trenches. D) spreading centers. E) fracture zones.
C) deep-sea trenches.
Underwater avalanches of muddy water mixed with rocks and debris are: A) graded bedding. B) deep sea fans. C) turbidity currents. D) turbidite deposits. E)white smokers.
C) turbidity currents.
Which of the following is an example of an active continental margin? Choose all that apply. A) west coast of Africa B) east coast of the United States C) west coast of Chile D) east coast of Brazil E) west coast of the United States
C) west coast of Chile E) west coast of the United States
A. abyssal hill B. abyssal plain D. seamount E. tablemount
C. submarine canyon
rift valley
Deep faulted structure found along the axes of divergent plate boundary's; rift valleys can develop on the seafloor or on land
subduction zones
Deep ocean trenches are associated with______.
subduction
Deep, ocean trenches are found formed by which process? (folding, rifting, seafloor spreading, subduction)
Active continental margins are characterized by which of the following?
Deep-sea trenches
density stratification
Density stratification has caused the highest-density material to be found at Earth's core
Which of the following is an example of a passive continental margin? Southern Coast of Alaska West Coast of Chile East Coast of Japan East Coast of the United States West Coast of Mexico
East Coast of the United States
The first person we are aware of who determined the circumference of the Earth using trigonometry and the angle of sunlight at Alexandria, Egypt, was
Eratosthenes
The first person we are aware of who determined the circumference of the Earth using trigonometry and the angle of sunlight at Alexandria, Egypt, was:
Eratosthenes
true
Every continent is part of a tectonic plate. (true, false)
false
Every major tectonic plate contains a continent. (true, false)
Graded bedding is created by turbidity currents. As the current slows, the larger suspended pieces of sediment fall out first, and then progressively smaller pieces settle out.
Explain what graded bedding is and how it forms.
abyssal plains.
Extending from the base of the continental rises into the deep-ocean basins are flat depositional surfaces called:
Echo sounding is not a very reliable way to measure ocean depth because water is a poor transmitter of sound. True False
FALSE
Convergent plate boundaries occur when tectonic plates move in opposite directions.
False
Early Polynesians only traveled within sight of land.
False
Free oxygen was abundant in the Earth's primordial atmosphere.
False
In Europe, significant oceanographic knowledge was acquired during the Middle Ages.
False
Oceanic crust is less dense than continental crust because it is made of silica and manganese.
False
The three major provinces of the ocean floor are continental margins, deep-ocean basins, and submarine canyons. True False
False
Water depth decreases as you move away from the mid-ocean ridge.
False
Which of the following is the standard unit of ocean depth? Meter Mile League Foot Fathom
Fathom
false
For the most part, the edges of the continents are the tectonic plate boundaries. (true, false)
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? Graded Bedding Turbidity Currents Nonconformities Suspension Deposits Sandstone Layering
Graded Bedding
The book The History of Ocean Basins, which contained the idea of seafloor spreading, was written by geologist:
Harry Hess.
Turbidity currents erode material from canyons as currents move downslope.
How do turbidity currents affect canyons?
age increases
How does the age of deadline sediments change with increasing distance from the ocean ridge?
infrequently
How often do turbidity currents occur?
semi-solid rock
How would you describe the material found at #3? (lava, magma, molten metal, semi-solid rock)
magma
How would you describe the material found at #5? (lava, magma, molten metal, semi-solid rock)
What happens when two continental plates converge?
Neither subducts; instead, a mountain range forms.
Where is the Alpine Fault located? Alaska The Alps California New Zealand near Egypt
New Zealand
divergent boundaries
New ocean crust is formed at _______.
false
North Carolina is very close to a tectonic plate boundary. (true, false)
Of the following statements about ocean crust, which is/are true?
Ocean crust is destroyed at deep sea trenches.
Of the following statements about ocean crust, which is/are true? (2)
Ocean crust is destroyed at deep sea trenches. Ocean crust is created at the mid-ocean ridge.
False
Ocean trenches are deep linear scars in the ocean floor caused by the divergence of plates along divergent plate boundaries. True or False
Why is the average depth of the ocean much greater than the average height of land? A) Oceanic crust is more dense than continental crust. B) More erosion happens on land than in the ocean. C) Continental crust is less buoyant than oceanic crust. D) Oceanic crust is cooler than continental crust. E) Continental crust is thinner than oceanic crust.
Oceanic crust is more dense than continental crust.
divergent plate boundaries.
Oceanic ridges and rises result from seafloor spreading along:
true
Oceanic ridges are cut by a number of transform faults, which offset spreading zones.True or False
North American
On the map, #1 is the _____ plate. (African, Australian, Eurasian, North American, South American)
Australian
On the map, #11 is the _____ plate. (African, Australian, Eurasian, North American, South American)
Eurasian
On the map, #2 is the _____ plate. (African, Australian, Eurasian, North American, South American)
South American
On the map, #6 is the _____ plate. (African, Australian, Eurasian, North American, South American)
African
On the map, #7 is the _____ plate. (African, Australian, Eurasian, North American, South American)
Faster waves?
P waves
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? Arctic Ocean Indian Ocean Southern Ocean Pacific Ocean Atlantic Ocean
Pacific Ocean
Tamu Massif, the largest single volcano on Earth occurs in which of the following oceans? Pacific Ocean Indian Ocean Atlantic Ocean Southern Ocean Arctic Ocean
Pacific Ocean
The largest of the ocean basins, which currently covers more than half of the ocean surface, is the
Pacific Ocean
The largest of the ocean basins, which currently covers more than half of the ocean surface, is the:
Pacific Ocean
supercontinent 250 million years ago
Pangaea
deep-sea trenches.
Passive continental margins are characterized by all of the following except: thick sediment accumulation. broad continental shelves. deep-sea trenches. very little volcanic and earthquake activity. shallow coastal waters.
asthenosphere
Tectonic plates float on top of a semi-solid, taffy-like layer called the _____. (asthenosphere, crust, lithosphere, mantle, mesosphere
convection
Tectonic plates motion is caused by _____ in the asthenosphere. (conduction, convention, insulation, radiation)
Converging continental-continental
The Himalayas in South Asia are an example of what type of plate boundary?
North American
The United States is part of the _____ plate. (African, Australian, Eurasian, North American, South American)
Of the following statements about the asthenosphere, which is/are true?
The asthenosphere is very hot and contains areas of partially molten rock The asthenosphere is a plastic layer that extends from the base of the lithosphere to a depth of about 700 kilometers (430 miles).
False
The continental shelf is generally defined as a steeply sloping zone extending from the shoreline to the shelf break. True or False?
False
The deepest portions of the ocean are part of the relatively narrow features called submarine canyons. True or False?
in the same direction as the plates are spreading.
The direction of motion along a seafloor transform fault is:
4,000-5,000 m below sea level
The greatest proportion of Earth's surface lies in this elevation/depth interval.
transform
The type of plate boundary where tectonic plate *slide* past one another sideways is called a _____ plate boundary. (convergent, divergent, tectonic, transform, transitional)
divergent
The type of plate boundary where tectonic plates move away from one another (*divide*) is called a _____ plate boundary. (convergent, divergent, tectonic, transform, transitional)
convergent
The type of plate boundary where tectonic plates move towards one another (*collide*) is called a _____ plate boundary. (convergent, divergent, tectonic, transform, transitional)
How is the age distribution pattern of the Hawaiian Islands-Emperor Seamount chain explained by the position of the Hawaiian hot spot?
The volcanoes in the Hawaiian Island-Emperor Seamount chain get progressively older as one heads northwestward from Hawaii. These age relationships suggest that the Pacific Plate has been steadily moving northwestward, while the underlying mantle plume has remained relatively stationary.
Describe the origin of Earth's oceans
The water that fills our oceans was mostly derived from outgassing, with a minor component coming from ice comets
false
There are sometimes gaps between neighboring tectonic plates. (true, false)
What do all plate boundaries have in common? Select only one answer.
They are all associated with zones of earthquakes.
What do all plate boundaries have in common?
They are all zones of earthquakes
Of the following statements about sea floor magnetic anomalies, which is/are true?
They are oriented parallel to the mid-ocean ridge
Of the following statements about sea floor magnetic anomalies, which is/are true?
They are oriented parallel to the mid-ocean ridge.
outer core b/c it's liquid
Through which earth later are S waves NOT transmitted through and why?
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? Fracture zone Guyots Nemataths Seaknolls Transform fault
Transform fault
movement occurs in the same direction.
Transform faults have all of the following characteristics except:
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. Rift valley Pillow basalts Metal sulfide deposits Seamounts Trenches
Trenches
subduction
Volcanoes (on the land and in the ocean) are mostly formed by which process? (folding, rifting, seafloor spreading, subduction)
In science, which one of the following would be considered an observation
Waves are seen to approach the beach at an angle
In science, which one of the following would be considered an observation?
Waves are seen to approach the beach at an angle.
What was the main reason scientists objected to Alfred Wegener's idea of continental drift?
Wegener's proposed mechanism for movement was thought to be against the laws of physics.
What was the main reason scientists objected to Alfred Wegener's idea of continental drift?
Wegener's proposed mechanism for movement was thought to violate the laws of physics.
Pangea
Wegner's continental drift hypothesis stated that all the continents once joined together to form ________
seafloor spreading
What *process* creates new, oceanic tectonic plate material at divergent boundaries? (folding, rifting, seafloor spreading, subduction)
subduction
What *process* destroys old, oceanic tectonic plate material at convergent boundaries? (folding, rifting, seafloor spreading, subduction)
dense mixtures of sand, mud, and other debris that move at high speeds down submarine canyons
What are turbidity currents?
mid-ocean ridge
What is found at #1? (huge earthquakes, mid-ocean ridge, ocean trench, volcano)
semi-solid rock flowing
What is happening at #4? (magma rising, lithosphere melting, semi-solid rock flowing)
ocean trench
What is physical feature is found on Earth's surface at #3? (ocean trench, sinkhole, volcanoes, whirlpool),
Hydrothermal vents are home to unusual deep-ocean ecosystems that include giant tubeworms, large clams, beds of mussels, and many other creatures. These organisms are able to survive in the absence of sunlight because the vents discharge hydrogen sulfide gas, which is metabolized by Archaea (bacteria adapted to harsh conditions) to provide a food source for other organisms.
What kinds of unusual life can be found associated with hydrothermal vents? How do these organisms survive?
mountain chain
What physical feature do we find on Earth's surface at #1? (mid-ocean ridge, mountain chain, volcanoes, volcanic island arc)
rifting
What process can tear continents apart at divergent boundaries? (folding, rifting, seafloor spreading, subduction)
folding
What process creates mountain chains at convergent boundaries with continental crust? (folding, rifting, seafloor spreading, subduction)
seafloor spreading
What process does this picture show? (folding, rifting, seafloor spreading, subduction)
subduction
What process does this picture show? (folding, rifting, seafloor spreading, subduction)
all of these
What type of "activity: might you encounter are the edges of a tectonic plate? (earthquakes, mountain formation, volcanoes, all of these)
continental
What type of crust / lithosphere is shown? (continental, oceanic)
oceanic
What type of crust / lithosphere is shown? (continental, oceanic)
convection
What type of heat transfer is shown at #4? (conduction, convection, insulation, radiation)
convergent
What type of plate boundary is shown in the picture? (convergent, collisional, divergent, tectonic, transform)
divergent
What type of plate boundary is shown in the picture? (convergent, collisional, divergent, tectonic, transform)
convergent
What type of plate boundary is shown in the picture? (convergent, collisional, divergent, tectonic, transform, transitional)
convergent
What type of plate boundary is shown in the picture? (convergent, divergent, tectonic, transform, transitional)
all of these
What types of activity are found at plate boundaries like the one shown in the picture? (powerful earthquakes, tsunamis, underwater volcanoes, volcanic islands, all of these)
none of these
What types of activity are found at plate boundaries like the one shown in the picture? (powerful earthquakes, tsunamis, underwater volcanoes, volcanic islands, none of these)
powerful earthquakes
What types of activity are found at plate boundaries like the one shown in the picture? (powerful earthquakes, tsunamis, underwater volcanoes, volcanic islands, none of these)
graded bedding that begins as coarse material and becomes finer upward
What types of deposits do turbidity currents leave in alluvial fans?
could not provide a mechanism for continental movement
What was the main reason Wegners continental drift hypothesis was rejected?
repeated sequences of graded bedding that begin as coarse material and become finer upward
What would you look for as evidence that a rock layer formed from materials deposited by ancient turbidity currents?
What is sea-floor spreading?
When lava erupts through the narrow cracks formed long the oceanic ridge, adding new rock floor to the ocean floor.
earthquake
When two plates become stuck together and cannot move a(n) _____ is likely. (earthquake, volcanoes, new mountain)
very slow
Which best describes the speed of tectonic plate motion. (very slow, somewhat slow, fast, very fast)
seafloor spreading
Which process can be thought of as the opposite or reverse of subduction? (folding, rifting, seafloor spreading, none of these)
Do most lithospheric plates contain both oceanic- and continental-type crust?
Yes, most lithospheric plates contain both oceanic- and continental-type crust.
Continental shelf
a generally flat zone extending from the shore to the shelf break
continental shelf
a generally flat zone extending from the shore to the shelf break
multi-beam sonar
a method of mapping the topography of the ocean floor along a strip up to 60 km
The important contribution to navigation made by Eratosthenes in the third century BC was
a reasonably accurate calculation of the circumference of our planet
The important contribution to navigation made by Eratosthenes in the third century BC was __________.
a reasonably accurate calculation of the circumference of our planet
Which of the following is associated with a subduction zone?
a volcanic arc
Volcanic features on the ocean floor that are less than 1,000 meters (0.6 miles) tall are called: oceanic trenches. oceanic ridges. seamounts. tablemounts. abyssal hills or seaknolls.
abyssal hills or seaknolls.
Volcanic features on the ocean floor that are less than 1,000 meters (0.6 miles) tall are called: oceanic trenches. oceanic ridges. abyssal hills or seaknolls. seamounts. tablemounts.
abyssal hills or seaknolls.
An oceanographic vessel is mapping a section of the ocean floor stretching for tens of miles in all directions. The seafloor is extremely flat, with a slope of less than one degree, and the water depth is about 4,500 meters. The area being mapped is most likely a(n) __________. abyssal plain continental borderland continental rise continental slope continental shelf
abyssal plain
Extending from the base of the continental rises into the deep-ocean basins are flat depositional surfaces called
abyssal plains
Sediments deposited by the process of suspension settling produce the main sediment found on
abyssal plains
Sediments deposited by the process of suspension settling produce the main sediment found on ___________. Select only one answer. shallow islands in tropical seas the continental shelf abyssal plains the continental slope and rise submarine fans
abyssal plains
According to the nebular hypothesis
all bodies in the solar system formed from an enormous cloud composed of mostly hydrogen and helium, with only a small percentage of heavier elements
All of the following were accomplishments of Captain James Cook except
all of the above are correct
Evidence for continental drift includes:
all of the above.
Tablemounts
also called a guyot; sub-oceanic volcano with a flattened top that once existed about sea level
Describe how an echo sounder works
an echo sounder sends a signal from a ship downward into the ocean, where it produces echoes when it bounces off any density difference. The time it takes for the echoes to return to the point of origination is then used to determine the depth and corresponding shape of the ocean floor
If all were accessible, which of the following items would be best for geologists to examine to better understand Earth's internal structure?
an iron meteorite
Which of the following is characteristic of oceanic-continental convergent plate boundaries?
andesitic volcanoes
In general, where can the youngest ocean floor be found?
at the mid-ocean ridge
In general, where would the youngest ocean floor be found?
at the mid-ocean ridge
lithosphere atmosphere core asthenosphere mesosphere
atmosphere
With respect to mid-ocean ridges, transform faults are: a) located in submarine canyons. b) perpendicular to the ridge axis. c) parallel to the rift valley. d) associated with hydrothermal vents.
b) perpendicular to the ridge axis.
The measurement of ocean depth and the charting of seafloor topography is called __________. bathymetry navigation tomography cartography hydrology
bathymetry
Seamounts
below sea level but rises more than 1 kilometer above the surrounding ocean floor, with a conical or pointy top like an upside-down ice cream cone that never reached the ocean surface
passive continental margins are characterized by
broad continental shelf, shallow coastal waters, thick sediment accumulation, very little volcanic and earthquake activity
The faster the rate of spreading at the mid-ocean ridge or rise, the ________ the underwater volcanic mountain range.
broader (wider)
continental rise are formed
by many deep sea fans
One of the reasons that free oxygen in our atmosphere is important to the development and maintenance of life on Earth is because oxygen
can form ozone and block some UV radiation
One of the reasons that free oxygen in our atmosphere is important to the development and maintenance of life on Earth is because oxygen:
can form ozone and block some UV radiation.
P waves
can go through liquid rock
S waves
cannot go through liquid rock
characteristics of active continental margins include
chains of islands, deep-sea trenches, volcanic activity, earthquake activity
core
composed mostly of iron and nickel with a liquefied metallic outer layer
mantle
contains minerals rich in iron and magnesium, between the crust and the core, and has the second largest volume according to the chemical classification
Along which of the following would you NOT expect to find active volcanic activity?
continental collision zone
Where would you NOT expect to find significant volcanic activity?
continental collision zone
Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Please identify the word and/or phrase that does NOT fit the pattern. Enter only the letter of the answer (caps, no period, and not the full entry) in the field below. A. abyssal plain B. continental flood basalt C. continental rise D. continental shelf E. continental slope
continental flood basalt
All continents fit together with the least number of overlaps and gaps when the continents are matched along:
contours at around 2000 meters in depth
An ocean trench is associated with what type of plate boundary?
convergent
An ocean trench is associated with which type of plate boundary?
convergent
Trenches are typically associated with ________. convergent continental margins fracture zones passive continental margins transform continental margins abyssal hills
convergent continental margins
lithosphere
crust and the uppermost mantle consisting of a solid rock layer
The lithosphere consists of Earth's
crust and uppermost mantle
The lithosphere consists of Earth's __________.
crust and uppermost mantle
Ocean trench
deep linear scars on the deep-ocean floor caused by plate convergence
ocean trench
deep linear scars on the deep-ocean floor caused by plate convergence
old lithospheric is destroyed in association with
deep sea trenches
Passive continental margins are characterized by all of the following except:
deep-sea trenches
Passive continental margins are characterized by all the following except: broad continental shelves. shallow coastal waters. thick sediment accumulation. very little volcanic and earthquake activity. deep-sea trenches.
deep-sea trenches.
What are turbidity currents
dense mixtures of sand, mud, and other debris that move at high speeds down submarine canyons
The separation of the Earth into layers while it was molten was the result of the
differing densities of the elements that make up the Earth
The separation of the Earth into layers while it was molten was the result of the:
differing densities of the elements that make up the Earth
The East Pacific Rise is associated with which type of plate boundary?
divergent
Plate boundaries where new oceanic crust is being added are called _____________.
divergent boundaries
The Mid-Atlantic Ridge is an example of a:
divergent boundary
Oceanic ridges and rises result form seafloor spreading along:
divergent plate boundaries
Oceanic ridges and rises result from seafloor spreading along: transform plate boundaries. convergent plate boundaries. divergent plate boundaries. none of the above.
divergent plate boundaries.
The Mid-Atlantic Ridge is an example of a:
divergent plate boundary.
Indian
does not fit
Jurassic
does not fit
Ptolemy
does not fit
atmosphere
does not fit
oxygen
does not fit
The direction of motion along a seafloor transform fault is: A) associated with turbidity currents. b) in the same direction as the ridge offset. c) influenced by underwater boundary currents. d) perpendicular to the direction of plate movement. e) in the same direction as the plates are spreading.
e) in the same direction as the plates are spreading.
Your job is to locate the world's plate boundaries. To do this, you may use only one map. The best map to choose for this job is a map that shows the worldwide locations of ___________________.
earthquakes
transform boundaries form what geological events?
earthquakes
Submarine canyons were most likely formed by: deposition of terrestrial sediment. erosion by turbidity currents. erosion by major rivers in the past. scouring by glaciers during the last ice age. earthquake activity.
erosion by turbidity currents.
All the following were accomplishments of Captain James Cook except :
exploring the Southern Ocean near Antarctica. mapping of unknown islands, including Hawaii, in the Pacific. measuring environmental characteristics such as water temperature. determining the outline of the Pacific Ocean.
Due to the very harsh environmental conditions, very few types of organisms are found in association with hydrothermal vents
false
Due to the very harsh environmental conditions, very few types of organisms are found in association with hydrothermal vents. True False
false
Hydrothermal vents are seafloor cold seeps with high concentrations of sulfur and salts. True False
false
Mid-Ocean ridges are rises that occupy a small portion of the deep ocean basin, only around 10%
false
Mid-ocean ridges are rises that occupy a small portion (around 10%) of the deep ocean basins. True False
false
New crust is formed at trenches and older crust is subducted at oceanic ridges.
false
Ocean trenches are deep linear scars in the ocean floor caused by the divergence of plates along divergent plate boundaries
false
Ocean trenches are deep linear scars in the ocean floor caused by the divergence of plates along divergent plate boundaries. True False
false
Seamounts are from ancient tablemounts
false
The continental shelf is generally defined as a steeply sloping zone extending from the shoreline to the shelf break
false
The deepest portions of the ocean are part of the relatively narrow features called submarine canyons
false
The magnetic field of the Earth reverses itself each time that magma erupts at a mid-ocean ridge.
false
The magnetic north pole has remained very close to the geographic North Pole throughout all of geologic time.
false
The majority of the world's hotspots are associated with plate boundaries.
false
The three major provinces of the ocean floor are continental margins, deep-ocean basins, and submarine canyons
false
the deepest portions of the ocean are part of the relatively narrow features called submarine canyons
false
Consider a continental margin that has a very broad, flat continental shelf and a slope that descends 1 km to the deep ocean basin. Based on this information, this margin is ___________________. lacking a continental rise seismically active near an offshore fault far from an oceanic ridge a continental borderland
far from an oceanic ridge
Consider a continental margin that has a very broad, flat continental shelf and a slope that descends 1 km to the deep ocean basin. Based on this information, this margin is ___________________. far from an oceanic ridge near an offshore fault lacking a continental rise seismically active a continental borderland
far from an oceanic ridge
Eratosthenes
first determination of Earth's circumference
Abyssal plain
flat depositional surfaces that cover extensive portions of the deep-ocean basins
Match the term with the appropriate phrase. abyssal plain a generally flat zone extending from the shore to the shelf break narrow and deep valleys on continental slopes shallow-water areas close to continents flat depositional surfaces that cover extensive portions of the deep-ocean basins deep linear scars on the deep-ocean floor caused by plate convergence
flat depositional surfaces that cover extensive portions of the deep-ocean basins
abyssal plain
flat depositional surfaces that cover extensive portions of the deep-ocean basins
deposition by waves
formation of continental shelves
All of the following are considered part of the continental margin expect the:
fracture zone
All the following are considered part of the continental margin except the: submarine canyon. continental shelf. fracture zone. continental rise. continental slope.
fracture zone
Coral reef development includes the following stages:
fringing reef, barrier reef, atoll
What is the characteristic layering of an individual turbidity current deposit called? velocity profile graded bedding layered stratum grand layering rip current
graded bedding
Explain what graded bedding is and how it forms
graded bedding is created by turbibity currents. As the current slows, the larger suspended pieces of sediment fall out first, and then progressively smaller pieces settle out.
What types of deposits do turbidity currents leave in alluvial fans
graded bedding that begins as coarse material and becomes finer upward
Overall, the Atlantic Ocean basin is ________, and the Pacific Ocean basin is ________.
growing; shrinking
A tablemount is another name for a(n) ________. island guyot seaknoll abyssal hill nematath
guyot
sound waves (specifically seismic reflecting profiling).
he method that used most frequently to investigate sediment and rock layers of the sea floor is:
If a container ship that is floating on water has weight removed from the deck, it would float __________ in relation to its previous position.
higher
Since the end of the last Ice Age, the melting of glaciers has caused continental landmasses to ride __________ with respect to the mantle.
higher
The Big Island of Hawaii is an example of a volcanic island associated with volcanic activity at a ________. hotspot transform fault deep sea trench island arc mid-ocean ridge
hotspot
ideas about the development of life on Earth make scientific sense
-As life developed on Earth, it began to significantly change Earth's environment
related to the formation of a density-stratified Earth
-Earth is layered based on density, with the highest-density material located at the deepest depths beneath Earth's surface
asthenosphere
-The asthenosphere is a plastic layer that extends from the base of the lithosphere to a depth of about 700 kilometers (430 miles)
Which of the following feature(s) is/are associated with the mid-ocean ridge? hydrothermal vents a central rift valley basalt volcanism and pillow lavas a trench thick layers of sediment volcanoes
-hydrothermal vents -a central rift valley -basalt volcanism and pillow lavas -volcanoes
Describe differences between transform faults and fracture zones
A transform fault is a seismically active are that shows evidence of pst transform fault activity. Two lithospheric plates are moving in opposite directions in a transform fault. A fracture zone, on the other hand, is a seismically inactive area that offsets the axis of a mid-ocean ridge. There is no relative motion because the lithospheric plates are moving in the same direction.
How did our Solar System begin to form?
A large cloud of dust and gas began to contract under the force of gravity.
slab-pull
A mechanism that contributes to plate motion in which cool, dense oceanic crust sinks into the mantle and pulls the trailing lithosphere along
ridge-push
A mechanism that may contribute to the plate motion; involves the oceanic lithosphere sliding down the oceanic ridge under the pull of gravity
Multi-beam sonar
A method of mapping the topography of the ocean floor along a strip up to 60 Km
what is a continental margin?
A part of a continent thats covered in shallow water
divergent boundary
A region where the rigid plates are moving apart, typified by the oceanic ridges
How can plate tectonics be used to help explain the difference between a seamount and a tablemount?
A seamount is a volcano with a cone-shaped top, whereas a tablemount is a volcano with a flattened top. Though both of these features originate at the crest (and topographic high) of the mid-ocean ridge, a tablemount has been subject to wave erosion when it rises above sea level. When the crust containing the tablemount is pushed away from the crest (and therefore onto a topographically lower position), or is moved away from a hot spot, it is re-submerged with its flat top.
5,550 meters
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?
Deep ocean trench
A surface future in the seafloor produced by the descending plate during subduction
Characteristics of passive continental margins include which of the following? A) Broad continental shelves B) Chains of islands C) Volcanic and earthquake activity D) Deep-sea trenches E) Thin sediment accumulation
A) Broad continental shelves
Imagine you are a geological oceanographer. As an expert, you are asked by a student to recommend the technique that would produce the most detailed map of a deep-water seamount near Hawaii. Which instrument would you recommend? multibeam echo sounder side-scan sonar precision depth recorder satellite altimetry seismic reflection
side-scan sonar
The two relatively flat areas on the hypsographic curve represent
some interior continental areas/ coastal plains and abyssal plains on the ocean floor
Oceanic ridges are cut by a number of transform faults, which offset spreading zones
true
Sediments of the continental rise can exhibit characteristics similar to those formed by rivers on land
true
The Wilson Cycle uses plate tectonic processes to show the life cycles of ocean basins during their growth, formation, and destruction over geologic time.
true
a sediment-laden current that flows off the continental shelf is called turbidity current
true
oceans with passive margins have continental slopes with more gradual slopes than oceans with active margins
true
the broadest continental shelves occur in the Arctic Ocean
true
Underwater avalanches of muddy water mixed with rocks and debris are:
turbidity currents
underwater avalanches of muddy water mixed with rock and debris are
turbidity currents
Which of the following is characteristic of continental-continental convergent plate boundaries?
uplifted mountain ranges
Match the term with the appropriate phrase. precision-depth recorder (PDR) a method of mapping the topography of the ocean floor along a strip up to 60 km used to determine ocean structure beneath the sea floor measurement of ocean depth and seafloor topography uses high frequency sound waves to measure ocean depth cumulative plot of area versus depth or elevation
uses high frequency sound waves to measure ocean depth
Precision-depth recorder (PDR)
uses high frequency sound waves to measure ocean depth
precision-depth recorder (PDR)
uses high frequency sound waves to measure ocean depth
All true oceanic islands are ________ in origin. sedimentary metamorphic volcanic collisional erosional
volcanic
Abyssal hills
volcanic features on the ocean floor are less than 1km; some of hte most abundant features on the planet that cover a large percentage of the entire ocean basin floor
Nearly all oceanic islands are
volcanic in origin
Nearly all oceanic islands are __________. (Choose the best answer.) parts of volcanic island arcs volcanic in origin parts of continents separated from continents formed at high-standing areas of mid-ocean ridges formed at hot spots as lithospheric plates pass over mantle plumes
volcanic in origin
Current scientific knowledge indicates that the most likely origin of most of Earth's oceans was due to
water vapor released from volcanic outgassing
Current scientific knowledge indicates that the most likely origin of most of Earth's oceans was due to:
water vapor released from volcanic outgassing
Warm water (From 30°C to 350°C) hydrothermal vents form: black smokers. abyssal hills. turbidity currents. white smokers. cold seeps.
white smokers
hydrothermal vents with extensive formations of precipitated barium sulfide are called
white smokers
Warm water (From 30°C to 350°C) hydrothermal vents form: abyssal hills. black smokers. white smokers. turbidity currents. cold seeps.
white smokers.
Of the following techniques, which one(s) can be used to map the sea floor? Choose all that apply. 1. recording many depths using a long cable 2. direct visitation of the sea floor 3. sending sound through water (sonar) 4. using satellites to measure the sea surface 5. measuring seawater clarity
1. recording many depths using a long cable 2. direct visitation of the sea floor 3. sending sound through water (sonar) 4. using satellites to measure the sea surface
A container holds 100 atoms of an isotope. This isotope has a half-life of 1.5 months. How many total atoms will be in the container after 3 months?
100 atoms
How much wider is the Atlantic Ocean today than when Christopher Columbus sailed? Assume that the Atlantic Ocean is getting wider at a rate of 3 centimeters per year (about 1 inch). (Round off the dates to the nearest century to make the calculation simpler.)
15 meters (about 49 feet)
What are 3 types of convergent boundaries?
2 oceanic plates converge, 2 continental plate converge, 1 oceanic and 1 continental plate converge
What are 2 types of divergent boundaries?
2 oceanic plates diverge, 2 continental plates diverge
If ocean crust forms at a rate of 10 centimeters per year, how much ocean crust can be created in 20 million years?
2000 kilometers
If ocean crust forms at a rate of 10 centimeters per year, how much ocean crust can be created in 20 million years? Select only one answer.
2000 kilometers
A container holds 100 atoms of an isotope. This isotope has a half-life of 1.5 months. How many atoms of the radioactive isotope will be in the container after 3 months?
25 atoms
The average depth of the world's oceans is approximately
3,682 meters (12,080 feet)
The average depth of the world's oceans is approximately:
3,682 meters (12,080 feet).
The greatest proportion of Earth's surface lies in this elevation/ depth interval
4,000-5,000 m below sea level
Earth is about
4.6 billion years old
Earth is about:
4.6 billion years old.
When did our Solar System begin to form?
5 billion years ago
A ships 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
5,500 meters
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? 3,000 meters 4,550 meters 5,550 meters 7,400 meters 11,100 meters
5,550 meters
A rock sample contains 75 atoms of a parent isotope and 25 atoms of a daughter isotope. The half-life of the parent isotope is 100 years. How old is this rock?
50 years
What percent of Earth's volcanic activity, each year, takes place on the seafloor? What percent of Earth's volcanic activity, each year, takes place on the seafloor? 80% 70% 75% 85% 65%
85%
A. oxygen B. water vapor C. carbon dioxide D. methane E. ammonia
A
convergent boundary
A boundary in which two plates move together
transform fault boundary
A boundary much to put slide past each other without creating or destroying lithosphere
Volcanic island arc
A chain of all Volcanic Islands generally located a few hundred Kilometers from a trench where subduction of one oceanic slab beneath another is occurring
mid-ocean ridge
A continuous elevated zone on the floor of all the major ocean basins
Continental drift
A hypothesis that originally proposed that the continents had once joined to form a single supercontinent
The cities of Los Angeles and San Francisco, CA, are about 380 miles apart. Plate motion along the San Andreas Fault is about five centimeters per year. If the Los Angeles Dodgers and the San Francisco Giants continue to play at their current locations, how long will it be before their games will constitute a cross-town rivalry?
About 12,230,000 years
10
About how many MAJOR tectonic plates are there? (10, 25, 50, 100, 1000)
fracture zone.
All of the following are considered part of the continental margin except the: continental shelf. fracture zone. continental rise. continental slope. submarine canyon.
Satellites are used to map the ocean floor because: they can cover areas where ships have not produced surveys. the shape of the ocean surface itself reflects large features on the seafloor below. they are unaffected by surface weather. they can "see" large areas of the seafloor at one time. All the above statements are correct.
All the above statements are correct.
oceanic trenches.
Along the margins of the Pacific are found most of Earth's:
Have the oceans always been salty
Although Earth's oceans have existed since early in the formation of the planet (at least 4 billion years ago), its chemical composition must have changed due to the high carbon dioxide and sulfur dioxide content in the early atmosphere, as well as volcanic outgassing of gases such as chlorine
The Dead Sea Fault separates which two tectonic plates? Eurasian and North American African and Indian Nazca and South American The Dead Sea Fault is a fracture zone and therefore does not separate two plates. Arabian and African
Arabian and African
lithosphere is not destroyed or produced
At a transform fault boundary, ______
A. Vasco de Gama B. Ptolemy C. Christopher Columbus D. John Cabot E. Ferdinand Magellan
B
A. black smoker C. hydrothermal vent D. rift valley E. white smoker
B. Deep focus earthquake
Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Please identify the word and/or phrase that does NOT fit the pattern. Enter only the letter of the answer (caps, no period, and not the full entry) in the field below. A. continental shelf B. abyssal hill C. shelf break D. continental rise E. continental slope
B. abyssal hill
The measurement of ocean depth and the charting of seafloor topography is called __________.
Bathymetry
measurement of ocean depth and seafloor topography
Bathymetry
True
Black smokers are hydrothermal vents that discharge superheated water with high concentrations of metal sulfides. True or False
Describe seafloor spreading and why it was an important piece of evidence in support of plate tectonics.
Captain Hess suggested that new ocean crust was created at the mid-oceanic ridges and disappeared back into deep Earth at the trenches near the edges of ocean basins. This was an important piece of evidence in support of plate tectonics because it provided a mechanism for continental and oceanic plate motion.
The first scientist to propose the origin of coral reefs based upon subsidence (sinking) of volcanic islands was:
Charles Darwin.
The European "Age of Discovery" began with
Christopher Columbus' discovery of the "New World."
The European "Age of Discovery" began with:
Christopher Columbus's discovery of the "New World."
Regarding glacial ages, why is it unlikely that the entire world was covered by ice 300 million years ago?
Coal deposits from the same geologic age are now present in North America and Europe, which formed from the remains of vast tropical swamp plants.
continental and oceanic crust
Continental crust is thicker and less dense than oceanic crust
Which of the following statements regarding continental and oceanic crust is TRUE?
Continental crust is thicker and less dense than oceanic crust.
Which of the following features is related to transform faults along mid-ocean ridges? Fracture zone Continental rise Submarine canyon Continental shelf Continental slope
Continental rise
Where does the deep-ocean basin begin along a passive continental margin? Shoreline Continental rise Continental slope Abyssal plain Continental shelf
Continental slope
Which of the following is the main reason that Earth has a magnetic field? Select only one answer.
Convection in the liquid iron-nickel outer core generates a magnetic field.
What boundary is formed when plates come together at boundaries or CRASH
Convergent
Name the 3 types of boundaries
Convergent, divergent and transform(strike-slip)
A. Adriatic B. Black C. Caspian D. Indian E. Mediterranean
D
Which of the following is a difference between passive and active continental margins? A) Passive margins have narrower continental shelves. B) Transform active margins will have a trench, whereas passive margins will not. C) Convergent active margins have continental borderlands associated with basins and islands along the coast, whereas passive margins have a flat continental shelf. D) Convergent active margins will have a steep continental slope, whereas passive margins will have a more gradual slope. E) Convergent active margins have a more extensive continental rise.
D) Convergent active margins will have a steep continental slope, whereas passive margins will have a more gradual slope.
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? A) The gentle slope above sea level B) The long and flat part below sea level C) The shallowest slope below sea level D) The steep deepest part below sea level E) The steep segment above sea level
D) The steep deepest part below sea level
A. Turbidity currents B. Graded bedding C. Turbidite deposits E. Deep-sea fans
D. Abyssal plains
A. rift valley B. oceanic ridge C. oceanic rise E. seafloor spreading
D. seaknoll
Of the following statements about density stratification, which is/are true?
Density stratification has caused the highest-density material to be found at Earth's core. Density stratification has caused Earth's internal structure to be layered. Outgassing is a direct result of density stratification. The origin of Earth's oceans and atmosphere are a result of density stratification.
The mid-ocean ridge is a topographically high feature, composed of basaltic lavas. Along the crest is a rift valley created by seafloor spreading. Cracks and faults are commonly observed in the central rift valley. Ocean ridges are segments of the mid-ocean ridge with a prominent rift valley and steep, rugged slopes resulting from slower plate divergence. Oceanic rises have slopes that are gentler and less rugged due to faster plate divergence.
Describe characteristics and features of the mid-ocean ridge, including the difference between oceanic ridges and oceanic rises.
A transform fault is a seismically active area that shows evidence of past transform fault activity. Two lithospheric plates are moving in opposite directions in a transform fault. A fracture zone, on the other hand, is a seismically inactive area that offsets the axis of a mid-ocean ridge. There is no relative motion because the lithospheric plates are moving in the same direction.
Describe differences between transform faults and fracture zones.
An echo sounder sends a sound signal from a ship downward into the ocean, where it produces echoes when it bounces off any density difference (e.g., the seafloor). The time it takes for the echoes to return to the point of origination is then used to determine the depth and corresponding shape of the ocean floor.
Describe how an echo sounder works.
South America and africa
Did geographic distribution of the swimming reptile mesosaurus provide evidence that was two continents were once joined?
Iceland is located on what type of plate boundary?
Divergent
What kind of boundaries are formed when plate moves or pulls apart?
Divergent
False
Due to the very harsh environmental conditions, very few types of organisms are found in association with hydrothermal vents. True or False
The relief in which of the following regions is similar to that found in mountain ranges on the continents? A) Abyssal plain B) Continental shelf C) Shoreline D) Continental rise E) Continental slope
E) Continental slope
A. Continental margin B. Active margin C. Convergent Active margin D. Transform active margin
E. Rift valley
Of the following techniques, which one(s) can be used to map 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 measuring sea water clarity
EVERYTHING BUT MEASURING
Of the following statements about Earth's hypsographic curve (figure shown below), which is/are true? The hypsographic curve shows that a majority of the exposed land is below 1 kilometer in elevation. 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 the percentage of Earth's surface area that is covered by ocean waters. The hypsographic curve shows the amount of water in the oceans. The hypsographic curve shows that a majority of the ocean floor is below 4 kilometers deep.
EVERYTHING BUT The hypsographic curve shows the amount of water in the oceans.
Which of the following ideas about the development of life on Earth make scientific sense?
Early organisms likely evolved into more complex organisms. As life developed on Earth, it began to significantly change Earth's environment. The "prebiotic soup" of the primitive oceans provided a likely environment for life to develop. Primitive life likely existed without the need for oxygen.
false
Earth's continents have always been about where they are now. (true, false)
false
Earth's lithosphere is a solid outer shell with no cracks. (true, false)
Describe Earth's magnetic field, including how it has changed through time.
Earth's magnetic field is composed of invisible lines of magnetic force that originate within Earth and travel out into space. The polarity of the field has reversed itself throughout geologic time.
faults
Earthquakes are usually associated with _______.
What kinds of unusual life can be found associated with hydrothermal vents? how do these organisms survive
Hydrothermal vents are home to unusual deep-ocean ecosystems that include giant tube worms, large clams, beds of mussels, and many other creatures. These organisms are able to survive in the absence of sunlight because the vents discharge hydrogen sulfide gas, which is metabolized by Archaea (bacteria adapted to harsh conditions to provide a source of food for other organisms
This is for the cumulative plot of the frequency of depth or elevation
Hypsographic curve
Of the following statements about nemataths and volcanic arcs, which is/are true?
In a volcanic arc, any of the volcanoes can be active at any time.
Of the following statements about nemataths and volcanic arcs, which is/are true? (All/5)
In a volcanic arc, any of the volcanoes can be active at any time. In a nematath, the age of the volcanoes progressively decreases as you move closer to the volcanic source. A nematath is created by a hotspot. Nemataths and volcanic arcs are both the result of volcanic activity. A volcanic arc is associated with a convergent plate boundary.
sediment is trapped within the trenches of the convergent plate boundaries ringing the Pacific
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 __________.
true
In the distance future, scientists predict that the continents will move and join together in a single, large landmass. (true, false)
created
In the picture, lithosphere is being _____. (created, destroyed, none of these)
none of these
In the picture, lithosphere is being _____. (created, destroyed, none of these)
destroyed
In the picture, lithosphere is being _____. (created, destroyed, none or these)
true
It is usually more calm and peaceful when you live farther from the edge of a tectonic plate. (true, false)
sea surface elevation, which varies depending on the shape of the underlying sea floor
Measurement of ocean floor bathymetry from satellites relies on ___________. Select only one answer.
seafloor spreading
Mid-ocean ridges are formed by which process? (folding, rifting, seafloor spreading, subduction)
plate tectonic processes
Most ocean floor features owe their origins to _________.
true
Most tectonic plate boundaries are found under the ocean. (true, false)
Continental volcanic arc
Mountains formed in part by volcanic activity caused by the subduction of oceanic lithosphere beneath a continent
a method of mapping the topography of the ocean floor along a strip up to 60 km wide
Multi-beam sonar
convergent
Name the type of plate boundary shown in the picture. (convergent, divergent, tectonic, transform, transitional)
divergent
Name the type of plate boundary shown in the picture. (convergent, divergent, tectonic, transform, transitional)
transform
Name the type of plate boundary shown in the picture. (convergent, divergent, tectonic, transform, transitional)
volcanic in origin
Nearly all oceanic islands are __________.
The first humans from Western Hemisphere known to have developed the art of navigation were the
Phoenicians
The first humans from Western Hemisphere known to have developed the art of navigation were the:
Phoenicians.
Subduction
Plates move together creating _______
folding, subduction
Powerful, mega-thrust earthquakes are produced by which two processes? (folding, rifting, seafloor spreading, subduction)
Which of the following is the predominant process that forms the metallic minerals in and around black smokers? Precipitation Suspension settling Undersea streams Melting icebergs Turbidity currents
Precipitation
uses high frequency sound waves to measure ocean depth
Precision-depth recorder (PDR)
Which of the following is the main reason that Earth has a magnetic field?
Rotation of the liquid iron-nickel outer core generates a magnetic field.
True
Satellites measurements of the ocean surface can be used to make maps of the seafloor. True or False?
False
Seamounts form from ancient tablemounts. True or False
What is the difference between an ocean and a sea
Seas are smaller and shallower bodies of saltwater, somewhat enclosed by land, but directly connected to the world oceans
abyssal plains
Sediments deposited by the process of suspension settling produce the main sediment found on ___________. Select only one answer.
True
Sediments of the continental rise can exhibit characteristics similar to those formed by rivers on land. True or False?
oceanic rises.
Segments of the oceanic ridge system that are gentler and less rugged in slope due to faster rates of seafloor spreading are called:
This is used to determine ocean structure beneath the sea floor
Seismic reflection profile
Imagine you are a geological oceanographer. As an expert, you are asked by a student to recommend the technique that would produce the most detailed map of a deep-water seamount near Hawaii. Which instrument would you recommend? Precision depth recorder Seismic reflection Multibeam echo sounder Side-scan sonar Satellite altimetry
Side-scan sonar
What boundary is formed by plates sliding past each other?
Slide-slip or transform
The first recorded attempt to measure the ocean's depth was conducted using which of the following techniques? Seismic Reflection Magnetometer Side-scan Sonar Multibeam Sonar Sounding
Sounding
What did Stanley Miller's experiment demonstrate
Stanley Miller's experiment demonstrated that vast amounts of organic molecules could have been produced in Earth's early oceans (a "pre-biotic soup")
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. Tablemount Abyssal plain Seamount Abyssal hill Submarine canyon
Submarine canyon
Which of the following is the predominant process that forms the thick blanket of sediment on abyssal plains the deep-ocean floor? Suspension settling Black smokers Precipitation Melting icebergs Undersea streams
Suspension settling
year
Tectonic plate motion is measured in centimeters per _____. (second, hour, day, month, year)
false
Tectonic plates are found deep inside of Earth and cannot be seen. (true, false)
lithosphere
Tectonic plates are massive pieces of Earth's _____. (asthenosphere, crust, lithosphere, mantle, mesosphere)
Describe how the half-life of radioactive materials can be used to determine the age of a rock through radiometric age dating
The half-life of a material is the time required for one-half of the atoms in a sample to decay to other atoms. The older Earth material is, the more radioactive material will have been converted to decay product(s). Scientists can measure the amount of radioactive material and the amount of resulting decay product in the rocks. By comparing these two quantities, the age of the material can be determined
Pacific
The largest tectonic plate without a continent is the _____ plate. Atlantic, Arctic, Indian, Pacific, Southern)
5 centimeters
The lithospheric plates move an average of ______ per year
Of the following statements about Earth's magnetic field, which is/are true?
The magnetic field is oriented vertical relative to Earth's surface at the south magnetic pole.
Of the following statements about Earth's magnetic field, which is/are true? (All, 5)
The magnetic field is oriented vertical relative to Earth's surface at the south magnetic pole. The magnetic field is oriented horizontal (parallel) to Earth's surface at the magnetic equator. Earth's magnetic field has varying dips around the world that range from vertical to horizontal, depending on latitude. the locations of Earth's magnetic poles have moved through time and have even reversed in polarity. The magnetic field is oriented vertical relative to Earth's surface at the north magnetic pole.
Which of the following statements best describes the relationship between Earth's geographic and magnetic poles?
The magnetic pole wobbles, but stays near the geographic pole
very deep ocean water depths
The majority of ocean trenches are associated with ___________.
Describe characteristics and features of the mid-ocean ridge, including the difference between ocean ridges and ocean rises
The mid-ocean ridge is a topographically high feature, composed of basaltic lavas. Along the crest is a rift valley created by seafloor spreading. Cracks and faults are commonly observed in the central rift valley. Ocean ridges are segments of the mid-ocean ridge with a prominent rift valley and steep, rugged slopes resulting from slower plate divergence. Oceanic rises have slopes that are gentler and less rugged due to faster plate divergence
Convection currents
The motion of matter resulting from changes in temperature do to earths unequal heating and causes tectonic plates to move
true
The motion of tectonic plates has shaped all living things on Earth. (true, false)
Why does the sea floor have a striped pattern of magnetic anomalies that is symmetric with respect to the mid-ocean ridge? (3)
The ocean floor is spreading apart, and new sea floor is forming. The igneous rock of the ocean floor preserves Earth's existing magnetic field as the rock cools. The polarity of Earth's magnetic field experiences reversals.
How is it that the floor of the ocean is so much younger than the ocean itself?
The ocean floor keeps regenerating itself.
How is it that the ocean floor is so much younger than the ocean itself?
The ocean floor keeps regenerating itself.
When an oceanic plate and a continental plate converge (collide) ,what happens?
The oceanic plate (which is denser) will slide beneath the continental plate and forms ocean trenches. it melts as it goes deeper, becoming magma, causing earthquakes and volcanoes
What happens when an oceanic and a continental plate converge?
The oceanic plate will be subducted.
Of the following statements about the age of the ocean crust, which one is true? Select only one answer.
The oldest ocean crust is about 200 million years old and is located near an ocean trench.
boundary
The place where two (or more) tectonic plates touch is called a plate _____. (boundary, edge, gap, zone)
subduction
The process by which oceanic crust sinks Beneath a trench. And back into the mantle at a colliding plate boundary
seafood spreading
The process by which plate tectonics produces new oceanic lithosphere at ocean ridges
Pangea
The proposed supercontinent that 200 million years ago began to break apart in form the present landmasses
Paleomagnetism
The study of changes in earths magnetic field, as shown by patterns of magnetism and rocks that have formed over time
False
The three major provinces of the ocean floor are continental margins, deep-ocean basins, and submarine canyons. True or False?
some interior continental areas/coastal plains and abyssal plains on the ocean floor.
The two relatively flat areas on the hypsographic curve represent:
What statement correctly distinguishes an ocean trench from a submarine canyon? Trenches are only located along active margins. Submarine canyons are only located along passive margins. Trenches are formed by erosive currents. Submarine canyons are drowned, ancient river valleys. Trenches descend deep beyond the abyssal plains. Submarine canyons are part of the shallower continental margins. Trenches occur only in the Pacific Ocean. Submarine canyons occur in all oceans.
Trenches descend deep beyond the abyssal plains. Submarine canyons are part of the shallower continental margins.
According to the Geologic Time Scale, which selection lists the correct order of coexistence, from earliest to latest
Trilobites and amphibians, insects and dinosaurs, dinosaurs and birds, flowering plants and fishes, humans and reptiles
According to the Geologic Time Scale, which selection lists the correct order of coexistence, from earliest to latest?
Trilobites and amphibians, insects and dinosaurs, dinosaurs and birds, flowering plants and fishes, humans and reptiles
A sediment-laden current that flows off the continental shelf is called a turbidity current. True False
True
Charles Darwin was the first person to propose a hypothesis on the origin of coral reefs.
True
Deep-sea trenches are found at convergent plate boundaries.
True
In general, the salinity content of ocean water has remained constant throughout the majority of Earth's history.
True
Most lithospheric plates contain both oceanic and continental crust.
True
Oceans with passive plate margins have continental slopes with more gradual slopes than oceans with active plate margins. True False
True
Radiometric dating is used to determine the ages of rocks.
True
Satellite measurements of the ocean surface can be used to make maps of the seafloor. True False
True
Satellites measurements of the ocean surface can be used to make maps of the seafloor
True
Sediments of the continental rise can exhibit characteristics similar to those formed by rivers on land. True False
True
The Earth's crust solidified around 4.5 billion years ago.
True
subduction
Tsunamis (giant, powerful waves) are produced by which process? (folding, rifting, seafloor spreading, subduction)
How do turbidity currents affect canyons
Turbidity currents erode material from canyons as currents move downslope
turbidity currents.
Underwater avalanches of muddy water mixed with rocks and debris are:
Which of the following is characteristic of oceanic-oceanic convergent plate boundaries?
Volcanic island arcs
converging oceanic-oceanic
Volcanic island arcs are associated with what type of plate boundary?
seamounts
Volcanic peaks on the deep-ocean floor with conical tops are called:
Word Analysis:
hydrothermal vents, Panamerica
A tentative, testable statement about the general nature of a phenomenon is called a/an
hypothesis
A tentative, testable statement about the general nature of a phenomenon is called a/an:
hypothesis
The direction of motion along a seafloor transform fault is:
in the same direction as the plates are spreading
the direction of motion along a seafloor transform fault is
in the same direction as the plates are spreading
Moving from oceanic ridge to oceanic trench, the thickness of the lithosphere:
increases in proportion to the distance
How often do turbidity currents occur
infrequently
The San Andreas Fault:
is a continental transform fault
Continental shelf
is a flat, gently sloping zone extending from the shore beneath the ocean surface to a point at which a marked increase in slope angle occurs
Submarine canyon
is a narrow, deep submarine valleys that are V-shaped in profile and have branches with steep to overhanging walls found on the continental shelf and slope
Continental rise
is a transition zone between the continental margin and the deep-ocean floor composed of a huge submerged pile of sediments
Deep sea fan
is deposits at the mouth of submarine canyons; create the continental rise when they merge along the base of the continental shelf
The term "scientific certainty"
is false because science never reaches an absolute truth, because we can never be certain that we have all of the observations
Differences in height between continental crust and oceanic crust are explained by:
isostasy
The vertical movement of Earth's crust due to the addition or removal of weight is called __________.
isostatic adjustment
What process is involved in the formation of continental shelves
large fluctuations in sea level
What is a nebula?
large, diffuse cloud of dust and gas in space
Climate distribution on Earth is primarily controlled by:
latitude
Continental slope
lies beyond the shelf break, with a steeper incline, extending out to the deep-ocean basin
Earthquakes can occur only in the __________.
lithosphere
Tectonic plates are pieces of the ________ that float on the more fluid ________ below.
lithosphere; asthenosphere
Continental drift was confirmed through the study of the:
location of magnetic poles through geologic time
During the height of the last Ice Age (~21,000 years ago), large glaciers made the continents ride __________ with respect to the mantle.
lower
As a tool, paleomagnetism is a piece of modern evidence that has helped support plate tectonics by showing that ________________.
magnetic sea floor "stripes" are symmetric with respect to the mid-ocean ridge
As a tool, the modern evidence from paleomagnetism has helped support plate tectonics by showing that ________________.
magnetic sea floor "stripes" are symmetric with respect to the mid-ocean ridge
Ptolemy
mapped world with Roman knowledge showing latitude and longitude
Match the term with the appropriate phrase. bathymetry used to determine ocean structure beneath the sea floor cumulative plot of area versus depth or elevation uses high frequency sound waves to measure ocean depth measurement of ocean depth and seafloor topography a method of mapping the topography of the ocean floor along a strip up to 60 km
measurement of ocean depth and seafloor topography
new lithosphere is produced at
mid-ocean ridges
The water in Earth's oceans came
mostly from volcanic outgassing and partly from comets
The water in Earth's oceans came __________.
mostly from volcanic outgassing and partly from comets
2 continental convergent plates form what geological events?
mountains
Transform faults have all of the following characteristics except:
movement occurs in the same direction
The Hawaiian Islands are located where the Pacific plate is:
moving over a hot spot
The Hawaiian Islands are located where the Pacific plate is:
moving over a hot spot or mantle plume.
Match the term with the appropriate phrase. submarine canyon flat depositional surfaces that cover extensive portions of the deep-ocean basins deep linear scars on the deep-ocean floor caused by plate convergence shallow-water areas close to continents a generally flat zone extending from the shore to the shelf break narrow and deep valleys on continental slopes
narrow and deep valleys on continental slopes
all of the following are features associated with active ocean margins
narrow continental shelves, young mountain chain, trench, volcanic arc
The majority of ocean trenches are associated with
narrow or no continental shelves
The Sun and the rest of the solar system formed about 5 billion years ago from a huge cloud of dust and gas called a
nebula
The Sun and the rest of the solar system formed about 5 billion years ago from a huge cloud of dust and gas called a:
nebula.
When two continental plates converge (collide), what happens?
neither plate sinks, instead, the two plates slowly fold and pile up on top of each other, forming mountains
The Hawaiian Islands are associated with which type of plate boundary?
none of the above (The Hawaiian Islands are not associated with a plate boundary.)
The Hawaiian Islands are associated with which type of plate boundary?
none of the above (The Hawaiian Islands are not associated with any plate boundary.)
basalt
oceanic crust
2 oceanic divergent plates form what geological events?
oceanic ridge, and sea-floor spreading
New lithosphere is produced in association with: fracture zones. deep-sea trenches. oceanic ridges. hydrothermal vents. transform faults.
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
Segments of the oceanic ridge system that are gentler and less rugged in slope due to faster rates of seafloor spreading are called: A)convergent plate boundaries. B)deep-sea trenches. C)transform faults. D)fracture zones. E)oceanic rises.
oceanic rises.
the most rapid change in slope in the ocean is found at the
oceanic trench
Along the margins of the Pacific are found most of Earth's:
oceanic trenches
Along the margins of the Pacific are found most of Earth's: oceanic trenches. tablemounts. oceanic ridges. abyssal hills or seaknolls. seamounts.
oceanic trenches
1 oceanic and 1 continental convergent plate form what geological events?
oceanic trenches, earthquakes,volcanic eruptions
When two oceanic plates converge(collide), what happens?
one plate (the denser one) is pushed beneath the other, melting as it goes deeper, becoming magma. This lava erupts and forms volcanic islands
A researcher interested in the vertical zonation of oceanic lithosphere would want to study __________.
ophiolites
The study of historical changes of continental shapes and positions is called:
paleogeography.
study of magnetism over geologic time
paleomagnetism
The seafloor magnetic pattern is best described as:
parallel to and symmetric about mid-ocean ridges.
The seafloor magnetic pattern is best described as:
parallel to and symmetric about ocean ridges
What happens during radioactive decay?
parent isotopes turn into daughter isotopes
Earth's current atmosphere supports animal life because
plant photosynthesis provides oxygen that is critical for aerobic respiration
Earth's current atmosphere supports animal life because __________.
plant photosynthesis provides oxygen that is critical for aerobic respiration
Fossils of ancient polar plants are currently found near the equator because the:
plants lived near the poles, but landmasses have drifted to current locations.
Most ocean floor features owe their origins to
plate tectonic processes
What would you look for as evidence that a rock layer formed from materials deposited by ancient turbidity currents
repeated sequences of graded bedding that begin as coarse material and become finer upward
Areas of intense volcanic activity that remain in more or less the same location over long periods of geologic time and are unrelated to plate boundaries are called hotspots.
true
Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Please identify the word and/or phrase that does NOT fit the pattern. Enter only the letter of the answer (caps, no period, and not the full entry) in the field below. A. continental margin B. active margin C. convergent active margin D. transform active margin E. rift valley
rift valley
Identify the major feature of a slow-spreading mid-ocean ridge. submarine canyon volcanic arc oceanic rise rift valley trench
rift valley
Identify the major feature of a slow-spreading mid-ocean ridge. submarine canyon trench volcanic arc oceanic rise rift valley
rift valley
2 continental divergent plate form what geological events?
rift valley and eventually a new ocean
Measurement of ocean floor bathymetry from satellites relies on
sea surface elevation, which varies depending on the shape of the underlying sea floor
Measurement of ocean floor bathymetry from satellites relies on ___________. Select only one answer. sea surface elevation, which varies depending on the shape of the underlying sea floor calculations of how much water versus rock there is at any ocean location density differences of ocean waters water temperature, which is higher in areas of shallow ocean waters and can easily be detected by satellites water flows off the high areas and into the low areas, making the ocean surface topography the exact inverse of the shape of the sea floor
sea surface elevation, which varies depending on the shape of the underlying sea floor
All of the following provide evidence for continental drift except:
seafloor magnetic pattern
Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Please identify the word and/or phrase that does NOT fit the pattern. Enter only the letter of the answer (caps, no period, and not the full entry) in the field below. A. rift valley B. oceanic ridge C. oceanic rise D. seaknoll E. seafloor spreading
seaknoll
Volcanic peaks on the deep-ocean floor with conical tops are called
seamounts
Volcanic peaks on the deep-ocean floor with conical tops are called: tablemounts. submarine canyons. oceanic ridges. oceanic trenches. seamounts.
seamounts.
abyssal hills are only visible in the pacific ocean because
sediment has covered those found in the other ocean basins
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
sediment is trapped within the trenches of the convergent plate boundaries ringing the Pacific
Match the term with the appropriate phrase. continental margin shallow-water areas close to continents narrow and deep valleys on continental slopes flat depositional surfaces that cover extensive portions of the deep-ocean basins deep linear scars on the deep-ocean floor caused by plate convergence a generally flat zone extending from the shore to the shelf break
shallow-water areas close to continents
The correct order of seafloor features from the coast to the mid-ocean ridge is:
shelf, slope, rise, abyssal plain
the correct order of marine provinces from the coast to the mid-ocean ridge is
shelf, slope, rise, abyssal plain
The correct order of seafloor features from the coast to the mid-ocean ridge is: abyssal plain, rise, slope, shelf. abyssal plain, shelf, slope, rise. slope, rise, shelf, abyssal plain. shelf, slope, rise, abyssal plain. rise, abyssal plain, slope, shelf.
shelf, slope, rise, abyssal plain.
Black smokers are hydrothermal vents that discharge superheated water with high concentrations of metal sulfides
true
The two relatively flat areas on the hypsographic curve represent: some interior continental areas/coastal plains and mid-ocean ridges. some interior continental areas/coastal plains and abyssal plains on the ocean floor. continental mountains and abyssal plains. continental slopes and deep-sea trenches. continental mountains and mid-ocean ridges.
some interior continental areas/coastal plains and abyssal plains on the ocean floor.
The method that is used most frequently to investigate sediment and rock layers of the sea floor is:
sound waves
The method that used more frequently to investigate sediment and rock layers of the sea floor
sound waves (specifically seismic reflecting profiling)
The method that is used most frequently to investigate sediment and rock layers of the sea floor is: sound waves (specifically seismic reflecting profiling). direct observation. drilling. light waves. satellite observation.
sound waves (specifically seismic reflecting profiling).
The first recorded attempt to measure the ocean's depth was conducted using which of the following techniques?
sounding
seafloor magnetic stripes
spreading center
What best describes the tectonic setting of the Cascade Mountains of the Pacific Northwest?
subduction zone
When one plate is moving towards another plate, the boundary between them is called
subduction zone
island arc
subduction zone
trench
subduction zone
Deep ocean trenches are associated with:
subduction zones
volcanoes on the seafloor that are flat-topped because of wave erosion are called:
tablemounts.
solar system
the Sun and the eight major planets revolving around it
What is the scientific definition of half-life?
the amount of time over which the number of parent isotopes decreases by half
Density stratification in relation to Earth's interior results in
the highest density materials concentrated toward Earth's core, whereas progressively lower density components form concentric spheres around the core toward the planet's surface
Vine and Matthews determined that new ocean floor was being produced at ocean ridges by examining:
the magnetic pattern on the seafloor
Loihi is __________.
the newest Hawaiian volcano
Two containers hold the same radioactive isotope. Container A contains 1000 atoms, and container B contains 500 atoms. Which of the following statements about containers A and B is true?
the rate of decay of atoms in container A is greater than the rate of decay of atoms in container B.
Satellites are used to map the ocean floor because ________.
the shape of the ocean surface reflects large features on the seafloor
Which of the following lines of evidence did Alfred Wegener use to support the concept of drifting continents? (4)
the way the shapes of the continents fit together like pieces of a jigsaw puzzle the distribution of species of fossils the pattern of similar mountain belts on different continents evidence of glaciers in areas that are now tropical
Oceans become deeper moving away from ridges due to:
thermal contraction of hot asthenosphere
Where did the energy of the Sun come from originally?
thermal energy that was converted from the gravitational energy of the original nebula collapse
satellites are used to map the ocean floor because
they are unaffected by surface weather, they can cover areas where ships have not produced surveys, they can "see" large areas of the seafloor at one time, the shape of the ocean surface itself reflects large features on the seafloor below
The San Andreas Fault is associated with what type of plate boundary?
transform
The San Andreas Fault is associated with which type of plate boundary?
transform
Where a mid-ocean ridge is offset, the linear feature connecting and between the crests of the ridge segments is called a __________. seismic fissure fracture zone hydrothermal vent transform fault central rift valley
transform fault
2 oceanic convergent plates form what geological events?
trenches and volcanic islands
Which of the following tropical islands would likely be the youngest?
tropical island without a fringing reef
Abyssal plains are more extensive on the seafloor of the Atlantic Ocean basin as compared to those on the seafloor of the Pacific Ocean basin. True False
true