(1) What is the difference between stress and strain?
(2) What is the difference between brittle and ductile deformation?
(a) What is the brittle-ductile transition
and where is it in the crust?
(3) How is deformational behavior influenced by the nature
of the rocks (or minerals) that are deforming?
(a) How about continent vs ocean
crust?
(4) What is the difference between a fracture, a fault, and a joint?.
(5) Make a small sketch to illustrate the nature of the following
faults: reverse fault, normal fault,
strike-slip fault, oblique slip fault.
(6) What is a fault scarp?
(7) What is the difference between an anticline and a syncline?
(a) A plunging syncline is
eroded. Sketch the exposed rock strata and mark the strata expected to be oldest
and youngest.
(8) What is the difference between and earthquake hypocenter
and a epicenter?
(a) How can you use S
and P wave arrival times to determine the location of the hypocenter?
(9) How are earthquake magnitudes measured? Explain
the 0 to 9 scale that is used.
(a) What is an aftershock?
(10) Explain how "first motion studies (focal mechanisms) can be
used to determine the nature of the offset on a fault
(i.e reverse vs. normal
or right lateral vs. left lateral).
(11) How can geology be used to describe past plate motions and
past earthquakes?
(12) What are two methods to measure the present rate of motion on faults? Which gives the more complete picutre of ground deformation?
(13) Why can subduction zones produce earthquakes that are 10 to 100 times larger than the largest transform or divergent margin earthquakes?
1) Permanent deformation of a material occurs at its A) elastic modulus. B) elastic limit. C) limit of strength. D) shear strength. E) brittle limit.
2) The strongest rock in this group is A) mudstone. B) quartzite. C) rock salt. D) basalt. E) schist.
3) Which behavior would be characteristic of rocks deep in the Earth's crust? A) faulting B) fracturing C) low-grade metamorphism D) mild folding E) flow
4) The depth of the brittle-ductile transition of the continental crust is controlled by the mineral A) olivine. B) feldspar. C) quartz. D) biotite. E) pyroxene.
5) The jointing pattern typical of lava flows is A) sheeting. B) columnar. C) exfoliation. D) bedding. E) faulting.
6) Checkerboard Mesa in Zion is famous for complex joint patterns formed by A) expansion. B) crystallization. C) faulting. D) exfoliation. E) metamorphism.
7) The fault parameter measured as a compass direction is the A) dip. B) throw. C) footwall. D) hanging wall. E) strike. Match the fault structures with their common mode of occurrence in the questions below.
8) A fault produced by crustal extension A) normal fault B) hanging fault C) thrust fault D) graben E) strike-slip fault
9) Low angle reverse fault at a convergent boundary A) normal fault B) hanging fault C) thrust fault D) graben E) strike-slip fault
10) Fault block found at spreading ridge crests and rift valleys A) normal fault B) hanging fault C) thrust fault D) graben E) strike-slip fault
11) Fault block which relatively moves up during reverse faulting A) normal fault B) hanging fault C) thrust fault D) graben E) strike-slip fault
12) A fault characteristic of transform plate boundaries A) normal fault B) hanging fault C) thrust fault D) graben E) strike-slip fault
13) Faults are often detected by the presence of A) a scarp. B) gouge. C) dislocated layers. D) slickensides. E) all of the above
14) The fold type which signifies the most extreme compression is a(n) A) anticline. B) syncline. C) monocline. D) plunging fold. E) isoclinal fold.
15) A crack in a rock along which there has been no faulting is a A) joint. B) fold. C) axis. D) thrust. E) trench.
16) A fold in which the limbs are parallel to one another is regarded as A) isoclinal. B) open. C) overturned. D) recumbent. E) overclinal.
17) A fold in which the limbs of the fold are inclined away from the hinge of the fold is a(n) A) anticline. B) syncline. C) geocline. D) thermocline. E) straightline.
18) An anticline is A) a fold whose limbs dip away from the axial plane. B) a fold whose limbs dip toward the axial plane. C) a compass needle inclined toward the south pole. D) the force that prevents earthquakes. E) all of the above
19) For any give strike, how many possible dip directions are there? A) an infinite amount B) two C) one D) none E) one if by land, two if by sea
20) The strike of a layer or bed of rocks is A) the steepest direction of slope of that bed. B) the intersection of a vertical plane with that bed. C) the intersection of a fault with that bed. D) the line defined by the intersection of a horizontal plane with that bed. E) none of the above
21) Plastic strain results in A) no deformation. B) cracks and fractures C) permanent bending or distortion. D) earthquakes. E) none of the above
22) Stress is best defined as A) a chemical process. B) atoms per unit area C) force per unit area. D) the result of strain. E) feet per unit area.
23) Stretching a rubber band between two fingers illustrates A) brittle strain. B) plastic strain. C) the slingshot principle. D) capillary action. E) elastic strain.
24) Two structures produced by compression are A) anticline, strike-slip fault. B) strike-slip fault, anticline. C) monoclines, normal faults. D) normal fault, syncline. E) folds and reverse faults.
25) The type of folding characteristic of deep burial and high temperature is __________ folding A) ductile B) concentric C) shear D) flow E) all of the above
26) The deepest earthquake foci are found at A) divergent margins. B) transform margins. C) convergent margins. D) rift valleys. E) mantle plumes.
27) The focus of an earthquake is A) a point on the surface of the Earth. B) the point within the Earth where an earthquake originates. C) always in the core of the Earth. D) directly beneath the epicenter. E) directly above the epicenter.
Select the force pattern from A through E that controls structures and events in the regions below.
28) Basin and Range faulting (western U.S.) A) E-W compression B) E-W extension C) vertical convection D) negative volume change E) elastic strain 29) Intraplate earthquakes A) E-W compression B) E-W extension C) vertical convection D) negative volume change E) elastic strain
30) Rocky Mountains, U.S. A) E-W compression B) E-W extension C) vertical convection D) negative volume change E) elastic strain
31) Subduction zone earthquake foci below 410 km A) E-W compression B) E-W extension C) vertical convection D) negative volume change E) elastic strain
32) Periodic stick-slip motion A) E-W compression B) E-W extension C) vertical convection D) negative volume change E) elastic strain
33) Seismic waves detected at large distances from the epicenter are called A) seismometer. B) seismograms. C) Richter waves. D) teleseisms. E) strong motion seismometers.
34) Seismology is A) the study of earthquakes. B) the study of plate tectonics. C) not concerned with geophysics of the Earth. D) not a branch of geology. E) the study of igneous rocks.
35) Perhaps the most important part of a seismometer is the A) heavy mass. B) oiled bearing. C) geospeaker. D) shape of the container. E) quartz spring. Match the earthquake size in A through E with a specific seismic event in the questions below.
36) Quake not felt by anyone A) 6.5 magnitude B) 7.0 magnitude C) 8.7 magnitude D) intensity I E) intensity VII
37) 30 times more energetic than magnitude 6 A) 6.5 magnitude B) 7.0 magnitude C) 8.7 magnitude D) intensity I E) intensity VII
38) Largest instrumentally measured quake A) 6.5 magnitude B) 7.0 magnitude C) 8.7 magnitude D) intensity I E) intensity VII
39) Largest exploded nuclear weapons A) 6.5 magnitude B) 7.0 magnitude C) 8.7 magnitude D) intensity I E) intensity VII
40) A quake which produces nearly total damage A) 6.5 magnitude B) 7.0 magnitude C) 8.7 magnitude D) intensity I E) intensity VII
41) In a single earthquake event, the crust moves 3 meters on the boundary of a plate moving 6 cm/year. How long had elastic strain been building up at this site? A) 50 years B) 18 years C) 500 years D) 180 years E) 1.8 years
42) An objective determination of the strength of an earthquake can be reported with the A) modified Mercalli scale. B) bathroom scale. C) Richter scale. D) Moh's hardness scale. E) fiducial scale.
43) The Mercalli scale is used to measure A) the lengths of Mercallies, a species of snakes found in southern Italy. B) weight C) volume. D) the absolute energy of an earthquake. E) the amount of damage done by an earthquake.
44) The minimum number of seismograph stations necessary for the precise determination of an earthquake epicenter is A) 1. B) 2. C) 3. D) 4. E) 5 or more.
45) Which of the following descriptions would most likely be for a earthquake of intensity XII? A) felt only by a few persons at rest, especially on upper floors of buildings B) felt by all, many frightened and run outdoors C) damage considerable in specially designed structures D) few, if any, masonry structures remain standing E) damage total
46) Earthquakes are associated with A) divergent plate boundaries. B) young folded mountain belts. C) convergent boundaries. D) volcanoes. E) all of the above
47) Every increase of one unit on the Richter scale (for example, m = 4 to m = 5) represents A) a 30x increase in the amount of damage done by an earthquake. B) a 10x decrease in the amount of energy released by an earthquake. C) a 10x increase in the magnitude of ground motion during an earthquake. D) a 1x increase in the magnitude of ground motion during an earthquake. E) a 10x increase in the amount of damage done by an earthquake.
48) Every increase of one unit on the Richter scale (for example, m = 4 to m = 5) represents A) an approximate 30þ increase in the amount of damage done by an earthquake. B) a 10þ decrease in the amount of energy released by an earthquake. C) a 100þ increase in the magnitude of actual ground motion during an earthquake. D) an approximate 30þ increase in the amount of energy released by the earthquake. E) a 10þ increase in the amount of damage done by an earthquake.
49) A small earthquake following a large earthquake is a(n) A) precursor. B) aftershock. C) trauma. D) wave orbit. E) none of the above
50) Slippage on an E-W right lateral fault produces compression in which of the following quadrants? A) SW, NE B) NW, SE C) NW, NE D) SW, SE E) NE only
51) Seismologists use this information to distinguish between fault and auxiliary planes. A) rupture direction B) plate motion direction C) waveform distribution D) aftershock distribution E) all of the above
52) Rupture propagates along a fault at a rate of about A) 3 m/sec. B) 30 m/sec. C) 150 km/sec. D) 3 mi/min. E) 3 km/sec.
53) If the average displacement along a fault during a quake is 8 m, and the rate of plate motion is 5 cm/year, the time interval between earthquakes averages A) 160 m. B) 16 years. C) 160 cm/year. D) 400 years. E) 160 years.
54) The San Andreas fault has moved about __________ km in its __________ million years of existence. A) 25; 5 B) 250; 50 C) 5; 250 D) 250; 5 E) 1000; 100
55) The plate motion measurement technique using quasar signals is A) VLBI. B) GPS. C) geodimeter measurements. D) optical leveling. E) offset stream beds.
56) Tiltmeters are ideal for monitoring A) strain accumulation. B) volcano deformation. C) the earthquake cycle. D) earthquake intensity. E) plate motion.
57) Volcanic eruptions are often preceded by A) harmonic tremors. B) increased land tilt. C) earthquake swarms. D) summit elevation. E) all of the above 58) The final event in the volcano deformation cycle is A) inflation. B) intrusion. C) harmonic motion. D) deflation. E) extrusion.
TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false.
59) Bulk modulus is a measure of the strength of Earth materials.
60) Ductile materials have a high elastic limit. 61) Faults are the result of brittle deformation.
62) Extrusive igneous rocks tend to be stronger than intrusive igneous rocks.
63) Quartz is a strong mineral, but the clays are weak.
64) Quartz becomes ductile at a depth of about15 km.
65) The San Andreas transforms plate boundary is a left-lateral strike slip fault.
66) Normal or reverse faults may flatten out into listric faults at depth.
67) Fold hinges maybe broad, or narrow and abrupt.
68) The Appalachian Mountain range is currently being built up tectonically..
69) The point plotted on a map to indicate earthquake location is the hypocenter.
70) Most earthquake energy is generated by the recovery of elastic strain.
71) Earthquakes in subducting slabs cease when the slab becomes thoroughly heated.
72) Earthquake foci decrease in depth away from the ridge axis.
73) Intraplate earthquakes generally take place at collisional boundaries.
74) The magnitude of an earthquake is a direct measure of the damage it causes.
75) For very tiny earthquakes, the Richter magnitude can be a negative number.
76) Large magnitude earthquakes are associated with long crustal ruptures.
77) A Richter magnitude of -2 is impossible..
78) It is likely that at some time an earthquake with a Richter magnitude of 12 will be recorded on Earth.
79) The epicenter of an earthquake is the point where the earthquake's energy is first released.
80) Earthquake moment is now regarded as the best measure of earthquake strength.
81) Fault creep rates are monitored with sensitive seismometers.
82) Foreshocks have been successfully used to predict several large earthquakes.
83) For great earthquakes, aftershocks can continue for years.
84) Earthquake rupture may combine strike-slip and dip-slip focal mechanisms.
85) Plate motions can be determined using magnetic sea-floor stripes.
86) Optical leveling to determine relative elevation depends upon orbiting satellites.
87) Relative plate motion steadily increases as a transform boundary is approached.
88) Some strainmeters can measure motions less than the diameter of an atom.
89) VLBI and GPS can detect plate motions of just a few millimeters.
90) Intraplate subsidence is commonly caused by cooling.
91) The effective thickness of the lithosphere's elastic layer decreases for longer time periods.
92) Hawaiian volcanoes grow through intrusion ass well as extrusion of lava.