review ch 10-13
Analyze Figure 12.13 in your textbook to estimate the age of the sea floor at the Mid-Atlantic Ridge.
0 - 9.7 million years
The wave amplitude of a Richter magnitude 6.7 earthquake is ______ times greater than the wave amplitude during a Richter magnitude 4.7 earthquake.
100
The wave amplitude of a Richter magnitude 6.5 earthquake is ______ times greater than the wave amplitude during a Richter magnitude 3.5 earthquake.
1000
The wave amplitude of a Richter magnitude 7.5 earthquake is ______ times greater than the wave amplitude during a Richter magnitude 4.5 earthquake.
1000
What is the difference in amplitude and energy released between a magnitude 3 earthquake and a magnitude 6 earthquake?
1000x, 32,678x
The energy released during a magnitude 7.1 earthquake is approximately ______ times large than the energy released during a magnitude 5.1 earthquake.
1024
How many years were required for a magnetic reversal to occur according to Glatzmaier and Roberts' computer simulation?
200,000
Review Figure 13.4b. What percentage of pine would is below water?
40%
What is the total displacement each year between the Pacific and North American plates?
5.6 cm per year
Which of the following correctly states the connection between lithosphere age and water depth?
A younger average lithosphere age corresponds with higher sea levels.
What is the Wadati-Benioff zone?
A zone of inclined earthquake foci that shows where the top of the subducting slab is and the angle of subduction
Which of the following is the footwall?
B
Which of the following statements would be correct of the associated diagram?
B is more dense than A
Which of the following factors is most influential in causing convection in the outer core?
Compositional differences create a difference in density.
Evaluate this statement. A younger average lithosphere age corresponds with lower sea levels.
False
Evaluate this statement. All past changes in sea level were due to the growth and demise of glaciers.
False
Evaluate this statement. Hot spots, with absolute certainty, can be used to determine absolute plate motions.
False
The following are examples of geologic structures resulting from compression:
Folds, reverse faults, and thrust faults(not sure)
The distinction between a joint and a fault is
Geologists make an important distinction between situations where rocks simply crack and where rocks slide past one another along a fracture. Joints are cracks where very little or no displacement of the rock occurred, as pictured in Figure 11.6. Faults are fracture planes along which rocks moved.
What happens as lower mantle rock just starts to rise?
It expands at decreased pressure.
What is a possible effect of a magnetic reversal on Earth's organisms?
Organisms are subjected to greater amounts of cosmic radiation.
The depth of the crust does not depend on
Review Section 13.1 and 13.3.
What hypothesis has been presented for the close parallel relationship of the magnetic field and the rotation axis?
Rotation causes spiraling convection currents in the outer core.
Which of the following statements is false about seismic tomography?
Seismic tomography definitely proves the plume hypothesis
Judge the following sentence according to the criteria given below. Earth is long overdue for a magnetic reversal because during the past 15 million years Earth's magnetic field reversed every 200,000 years, on average, and the last reversal was 780,000 years ago.
The assertion and the reason are both correct.
Judge the following sentence according to the criteria given below. Earth's magnetic field is due to a big mass of magnetized material inside Earth because magnets function only at relatively low temperatures.
The assertion is incorrect but the reason is correct.
Which statement is true about the lithosphere?
The lithosphere gets thicker as distance from the ridge increases, because it cools and the boundary between the lithosphere and asthenosphere occurs at greater depth.
Judge the following sentences according to the criteria given below. A student disputes the process of mantle convection. They argue that rock is solid and cannot flow. They challenge their classmates to provide evidence for present day mantle convection. A classmate shows them a seismic tomographic map and cross section showing variations in S-wave velocities.
The seismic tomographic map and cross section do show evidence for present day mantle convection and offers a strong affirmation of mantle convection.
Why do hot spots form a trail of extinct volcanoes over time?
The tectonic plates that contain the volcanoes move over time.
Read carefully through the following sentence, and decide which of the options is correct. Most mountain belts form near convergent plate boundaries where crust thickens by tensional shortening and by intrusion and crystallization of magma.
The word "tensional" should be replaced by "compressional."
Earth materials such as mud, sand, gravel or rock respond differently to passing seismic waves.
True
Evaluate the following statement: Lithosphere will subduct because it is older and colder, and thus denser, than the asthenosphere.
True
Transform fault boundaries are indicated by fault motion along faults that cross mid-ocean ridges with a motion consistent with plate motion defined at the ridges, rather than by a continuous ridge being broken into segments.
True
Far-western North America contains a variety of fault bounded crustal blocks called ________ terranes.
accreted
Why is the west coast of North America 500 km west of where it was about 540 million years ago?
accretion of exotic terrains
Compression causes
an increase in elevation because it shortens and thickens the lower crust.
A(n) ________ commonly forms a trap for oil and gas.
anticline
What type of structure is the following? Number 1 is the oldest rock layer.
anticline
Liquid metal at the base of the outer core moves upward due to ________ convection.
chemical
Which factor is not included in Glatzmaier and Roberts' model?
compositional convection
Which type of heat transfer occurs without any movement of matter?
conduction and radiation
What is the main factor that determines elevation?
crust type
All of the following are involved with mountain building between two continental plates, except
crustal thickening by volcano growth
The stresses responsible for present-day earthquakes in northeastern North America are a result of
glacial rebound.
Which factor is not important to the generation of magnetic current in Earth's core?
great heat in the core
What did Glatzmaier and Roberts' model suggest as a reason for magnetic reversal?
interactions between magnetic fields in the inner and outer cores
A brittle deformation
is a break that occurs at a relatively small strain.
What occurred to magnetic field strength in Glatzmaier and Roberts' model during polarity reversals?
it decreased
Which of the following is not likely to have an effect on ocean depth?
lava flow at ground faults
Which process is most common at transform boundaries?
lithospheric conservation
Which combination of factors would best lead to convection?
low viscosity, low heat conductivity, and high mass
What type of data to date is most useful for earthquake prediction?
monitoring known precursor events
What kind of fault do you see in the image? You have a cross-sectional view. Look at the displacement of rock in the center of the image.
normal
What kind of structure is this?
plunging anticline
Which feature is not usually caused by convergent boundaries?
rift valleys
Which is not a common component of explanations for mountains?
sedimentation
At greater depths, rocks are
stronger and more plastic
Which of the following is not a normal consequence of the convergence of two continental crust plates?
subduction of the thicker plate
What kind of structure is this? Letters give no indication of age. Strike and dip symbols give you general orientations.
syncline
Which of the following determines why subducting plates sink at a particular location?
the density of the lithosphere at the location
The Richter magnitude is based on
the maximum amplitude recorded
An event which may have caused the oceans to become shallower was
the rifting apart of Pangea in the Mesozoic.
Which property most inhibits convection?
viscosity
How does the age of the seafloor affect sea level? How does it affect water depth?
when seafloor is old, the sea level falls and water depth is very deep(NOT SURE)
In a sandbox with a crankable divider shown in Figure 11.14, which of the following may be illustrated?
Normal faults form in the area under tension and reverse faults form where the sand is squeezed together.
Which of the following present-day observations of crustal movement in formerly ice covered regions of North America and Eurasia support the flexural isostasy hypothesis?
Originally depressed areas are still rising and the bulges are sinking.
What observation supports the hypothesis that the slab-pull force is the primary cause of plate motion?
Plates with long subduction zones move faster than plates with short subduction-zones.
As the seafloor ages, ocean depth
increases.
What evidence suggests to scientists that magma generation at convergent boundaries is different than magma generation at mid-ocean ridges?
lava composition
What kind of faults do you see in the image? You have a map view (like flying over in an airplane). Look to the displacement of the gray or white bands of rock near the rock hammer.
left lateral strike slip
How do scientists measure the age of rocks at mid-ocean ridges?
magnetic polarity measurements
Using Figure 12.11 in your textbook, which option correctly identifies a time that polarity changed from normal to reverse and back?
normal to reverse: 3.33 million years ago, reverse to normal: 3.04 million years ago
Using the ages of the Hawaiian Islands in Figure 12.33, what direction is the Pacific plate moving?
northwest
Compared to its surroundings, the rising asthenosphere in mid-ocean ridges is
probably hotter and transmits seismic waves slower.
A model for Earth elevation based on oceanic crust being thinner than continental crust and oceanic crust being denser than continental crust results in
reasonable estimates of crustal thickness and crustal densities.
How does isostasy explain the formation of rift valleys?
root decreases under tension
Which of the following occurs as a result of compression?
shortening
The sea floor spreading hypothesis predicts that the mid-ocean ridges should be locations of rising asthenosphere. This prediction is supported by seismic data that indicates
slower seismic wave velocities at the ridges.
If Earth's remaining glaciers melt, how would the global sea level change?
the sea level would rise about 80 m
According to Figure 11.13, which option correctly describes the movement of two pins on either side of a plane in a block of clay submitted to tensional stress?
they move farther from the plane
According to Figure 11.13, which option correctly describes the movement of two pins on either side of a plane in a block of clay submitted to shear stress?
they slide along at the same distance from the plane in opposite directions
The principle of isostasy tells us that the key factor(s) determining the elevation of a floating object is(are)
thickness and density.
Which of the following is not an effect of tension?
thrust faults
In a normal fault, the footwall moves ________ relative to the hanging-wall.
up
Strike and dip is a method that geologists
use to measure the orientation of rocks
Choose the option that correctly orders the fluids from the one that sits at the bottom of a sandstone reservoir to the one that is closest to the low-porosity shale at the top of the reservoir.
water, oil, gas
In a syncline, the ________ rocks are exposed along the axis.
youngest
The energy released during a magnitude 8.3 earthquake is approximately ______ times large than the energy released during a magnitude 6.3 earthquake.
1024
If you're driving at 65 mph, and a car passes you going 85 mph, then the passing car has an absolute speed of 85 mph, but a relative speed of only ____ mph, when compared to your location, which is also changing.
20
If you're driving at 70 mph, and a car is heading towards you is going 90 mph, then the speeding car has an absolute speed of 90 mph, but a relative speed of only ____ mph, when compared to your location, which is also changing. The speeding car is ______ your car.
20, converging on
If you're driving at 60 mph, and a car passes you going 90 mph, then the passing car has an absolute speed of 90 mph, but a relative speed of only ____ mph, when compared to your location, which is also changing.
30
If you're driving at 90 mph, and you just sped past a car going 60 mph, then your speeding car has an absolute speed of 90 mph, but a relative speed of only ____ mph, when compared to your location, which is also changing. The car you passed up is ______ your car.
30, diverging from
The energy released during a magnitude 6.8 earthquake is approximately ______ times large than the energy released during a magnitude 3.8 earthquake.
32768
The energy released during a magnitude 7.1 earthquake is approximately ______ times large than the energy released during a magnitude 4.1 earthquake.
32768
What can be determined by looking at Figure 13.13?
Areas that are above sea level are growing and areas that are below sea level are sinking.
Why is there a difference in the number of faults involved at transform boundaries in the ocean and those on continents?
Continental crust is weaker than oceanic crust.
Which of the following factors is most influential in causing convection in the outer core?
Crystallization of iron creates a density contrast.
Evaluate the following statement: Gravity pulls a dense, subducted slab downwards, dragging the rest of the plate along into the trench. This is called the slab-suction force.
False
The plume hypothesis suggests that hot spots mark places where hot mantle conductively moves to the base of the lithosphere from the inner-outer core boundary
False
Explain how heat-flow data provide evidence for the existence of divergent plate boundaries.
Mid ocean ridges show higher heat flow than areas away from mid ocean ridges, proving the existence of divergent boundaries.
If a block of balsa, pine, oak, and rosewood were each submerged into a tub of water, why would the balsa wood project higher above the water than the other blocks of wood?
It is less dense.
Which term is defined as a measure of the amount of stress that a material can endure before it fails by breaking or flowing?
Strength
The magnetic bands preserved in the Atlantic oceanic plate are _________ with respect to the mid-Atlantic ridge providing evidence of seafloor spreading.
Symmetric
Judge the following sentence according to the criteria given below Mountains continue to rise long after tectonic forces cease to thicken crust and drive uplift along faults because mountains result both from tectonic deformation and isostatic response to erosion.
The assertion and the reason are both correct.
Judge the following sentence according to the criteria given below. Seafloor elevations decrease away from mid-ocean ridges because cooling lithosphere contracts, becomes denser and sinks down into the weak asthenosphere.
The assertion and the reason are both correct.
Judge the following sentence according to the criteria given below. Earth's magnetic field is due to a big mass of magnetized material inside Earth because magnets function only at relatively low temperatures. [The assertion is stated before the word "because;" the reason follows the word "because."]
The assertion is incorrect but the reason is correct.
Why does the heat flow dip east of the location where the Juan de Fuca Plate subducts beneath the North American Plate?
The cold subducted lithosphere dips there.
Evaluate the following statement. "Convection is a process of heat transfer that requires movement and is not possible in the solid rock regions of Earth."
The statement is false; solid rock movement is possible at a slow rate.
Which of the following statements is true about synclines?
The youngest rocks occur in the center and the limbs of the fold dip toward the center
Evaluate this statement: "Earthquake damage depends primarily on the magnitude of the quake."
This statement is true, but earthquake damage also depends on the proximity to the epicenter and the characteristics of materials through which the earthquake passes.
The following statements relate to processes that occur because of plate subduction. Which of the following statements is not true?
Volcanoes of this kind tend to have a single type of magma.
Which option describes a possible oil and gas trap?
an anticline with a sandstone layer underneath and a shale layer on top
Which of the following makes the best structural oil and gas trap?
an anticline with layers of low-porosity rocks overlying high-porosity rocks
If you were exploring for natural resources, such as oil or gas, explain what types of geologic structures you would look for to find oil and gas.
anticlines and dip-slip faults
When a rock undergoes stress greater than its yield strength, it is subject to:
brittle or plastic deformation
A model for Earth elevation based only on oceanic crust being denser than continental crust results in
continental and oceanic crust being too thick.
A model for Earth elevation based only on oceanic crust being thinner than continental crust results in
continental crust and oceanic crust having the same densities.
Continents are the product of mountain building at ancient ________ boundaries.
convergent
Plate C is positioned east of Plate D. If Plate C is moving at 6 mm/yr to the east and Plate D is moving 8 mm/yr to the east, then their relative motion is
convergent, 2 mm/yr
All of the following are involved with mountain building between an oceanic plate and a continental plate, except
crustal thickening by tensional stress
Plate C is positioned west of Plate B. If Plate C is moving at 7 mm/yr to the west and Plate B is moving 5 mm/yr to the east, then their relative motion is
divergent, 12 mm/yr
Plate C is positioned east of Plate D. If Plate C is moving at 8 mm/yr to the east and Plate D is moving 6 mm/yr to the east, then their relative motion is
divergent, 2 mm/yr
Plate A is positioned east of Plate B. If Plate A is moving at 10 mm/yr to the east and Plate B is moving 5 mm/yr to the east, then their relative motion is
divergent, 5 mm/yr
Analyze Figure 12.13 in your textbook to determine which of the following locations has the oldest floor.
east of Georgia
Which of the following is not a factor that increases the thickness of the crust?
flexure below thrust faults
What force is most responsible for convection on Earth?
gravity
What is the primary force that drives plate motion?
gravity