In Class Review Flashcards
1
Q
- The most famous and outspoken of the early proponents of continental drift was ______________.
A. Plato, for whom “plate tectonics” was named
B. Leonardo da Vinci
C. William Smith
D. Alfred Wegener
A
Alfred Wegener
2
Q
- The oldest rocks on the ocean floors are about ________ years in age.
A
200 million
3
Q
- The slide-past motions of long transform faults occur in all but which of the following?
A. In the northeastern Pacific as the Queen Charlotte fault, located near a sparsely populated region of Canada.
B. Along the San Andreas Fault in California with its famous earthquakes.
C. At the southwestern edge of the Pacific Ocean where the Alpine fault cuts across the South Island of New Zealand.
D. The west coast of South America.
A
D. The west coast of South America.
4
Q
- Faults on which the dominant motions are extensional are…
A. reverse fault
B. thrust faults
C. transform faults
D. normal faults
A
Normal Fault
5
Q
- ___________ faults are commonly found at areas of plate convergence where subduction or continental collision occurs.
A. Reverse
B. Normal
C. Transform
D. Strike-slip
A
Reverse
6
Q
- The strike-slip San Andreas Fault in California is a _______ fault more than 800 miles long.
A. right-lateral
B. left-lateral
C. thrust
D. normal
A
right-lateral
7
Q
- The point on the Earth’s surface directly above the point where the fault first ruptured is called the ____________.
A
epicenter
8
Q
- Which of the following wave types travels slowest through rock?
A. P-waves
B. S-waves
C. surface waves
D. They all travel with the same velocity.
A
Surface waves
9
Q
- Using the S-P timing method, epicenters can be located using seismograms from a minimum of ______ recording stations.
A. one
B. two
C. three
D. four
A
three
10
Q
- Earthquake moment is calculated by multiplying all but which of the following quantities together?
A. the shear strength of the rocks
B. the rupture area of the fault
C. the average displacement (slip) on the fault
D. the Modified Mercalli Intensity at the epicenter
A
the modified Mercalli intensity
11
Q
- Which of the following is NOT a divergent margin?
A. East African Rift
B. Mid-Atlantic Ridge
C. Aleutian Island Arc
D. East Pacific Rise
A
Aleutian Island Arc
12
Q
- Much of the San Francisco Marina District is built on artificial fill debris from the buildings ruined by the 1906 earthquake. Seismic waves in 1989 Loma Prieta earthquake were ____________ in this artificial fill (low velocity sediments).
A. damped (i.e., decreased or attenuated)
B. amplified
C. not noticeably affected
D. hybridized
A
Amplified
13
Q
- In San Francisco’s Marina district in 1989, some fill underwent permanent deformation and settling, and some formed slurries as underground water and loose sediment flowed like a fluid in a process known as ______________.
A. solifluction
B. creep
C. liquefaction
D. plasticity
A
Liquefaction
14
Q
- The viscosity of magma is lowered by __________.
A. increasing temperature
B. seismic waves
C. increasing SiO2 content
D. All of the above
A
Increasing temperature
15
Q
- Why does the magma from some volcanoes flow smoothly and relatively peacefully, while the magma from other volcanoes erupts violently over wide areas?
A. differences in the chemical and mineral makeup of magmas
B. variations in the temperature, water and gas content, and viscosity of magmas
C. different geographic positions with respect to hot spots and edges of tectonic plates
D. All of these are correct.
A
All of these are correction
16
Q
- A shield volcano has a great ___________.
A. height compared to its width
B. width compared to its height
C. amount of pumice
D. proportion of pyroclastic material, compared with lava flows
A
width compared to its height
17
Q
- Active volcanoes today in Oregon and Washington, including Mt. St. Helens, result from _________________.
A. heat generated by friction on the San Andreas Fault
B. the subduction of the Juan de Fuca plate beneath North America
C. the rifting of the Pacific plate along the East Pacific Rise.
D. continent-continent collision
A
the subduction of the Juan de Fuca plate beneath North America
18
Q
- Some of the deaths at Mt. St. Helens on May 18, 1980 were related to _____________.
A. the earthquake that preceded the eruption
B. people being overcome by fast-flowing basaltic lava
C. ash fall thousands of miles away
D. the effects of lateral blast and resulting pyroclastic flow
A
the effects of the lateral blast and resulting pyroclastic
19
Q
- Violent causes of death and injury from volcanic eruptions include.
A. A. pyroclastic flows
B. lahars
C. poison gases
D. All of the above.
A
All of the above
20
Q
- The 2004 Indian Ocean tsunami was generated by a magnitude 9.0 earthquake along __________ off the shore of Sumatra.
A. a subduction zone
B. a seafloor spreading center
C. an oceanic transform fault
D. a hotspot island chain
A
subduction zone
21
Q
- Tsunami typically have _________________________ relative to wind-blown waves.
A. short periods and short wavelengths
B. short periods and long wavelengths
C. long periods and short wavelengths
D. long periods and long wavelengths
A
long periods and long wavelength
22
Q
- The captain of a ship tells you that he once experienced a huge tsunami while sailing in the Pacific Ocean several hundred miles from any landmass. You decide that this sounds a little far-fetched because __________________.
A. tsunami usually occur only in the Indian Ocean and Caribbean Sea
B. tsunami are rarely felt in deep water because they have low heights
C. the ship could not have survived passing through a major tsunami in the open ocean
D. earthquakes do not occur in deep ocean waters
A
tsunami rarely felt in deep water because they have low heights
23
Q
- Most tsunami travel at speeds of ____________ miles per hour.
A. 4.2-4.8
B. 42-48
C. 420-480
D. 4200-4800
A
42-48 mph
24
Q
- Detailed mapping of the ocean bottom around the Hawaiian Islands revealed a previously unrecognized tsunami source. What did geologists discover on the seafloor in this area?
A. a major undersea strike-slip fault
B. a huge undersea meteor crater
C. a deep ocean trench along a subduction zone
D. slumps and debris avalanches formed by volcanic flank collapse
A
slumps and debris avalanches formed by volcanic flank collapse
25
Q
- Which of the following layer(s) of the Earth is a fluid?
A. Outer core
B. Inner core
C. Mantle
D. Crust
A
Outer core
26
Q
- In which layer of the Earth do most earthquakes occur?
A. Outer core
B. Inner core
C. Mantle
D. Crust
A
Crust
27
Q
- Which type of seismic wave will produce the most damaging ground shaking?
A. P waves
B. S waves
C. Surface waves
D. Ground waves
A
Surface Waves
28
Q
- Why are early warning systems for tsunamis easier to develop than early warning systems for earthquakes?
A. Because tsunamis take much longer to get to places they affect
B. Because it is impossible to predict where an earthquake will occur
C. Because tsunamis have a predictable recurrence interval
D. Because of the many hazards associated with earthquakes
A
Because tsunamis take much longer to ge tto places they affect
29
Q
- If you are sitting on a beach, all of the following are warning signs that a tsunami may be approaching except…
A. water receding water away from the shoreline
B. a wall of water approaching the shoreline
C. earthquake ground shaking
D. increased storminess over open water
A
increased storminess over open water
30
Q
- All of the following are ways to generate a volcanic melt except…
A. Decompression melting
B. Increasing the temperature of the rock
C. Lowering the melting point of the rock
D. Fractional crystallization
A
Fractional crystallization
31
Q
- Another class of active faults is created by southern California pushing into the “Big Bend” of the San Andreas fault. These faults are __________________.
A. mostly east-west-oriented normal fault
B. mostly north-south-oriented thrust faults (reverse faults)
C. mostly east-west-oriented thrust faults (reverse faults)
D. mostly north-south-oriented normal faults
A
mostly east-west-oriented thrust faults
