Geology Final

The presence of pillow lava is evidence of what volcanic circumstance? Select one: a. a submarine volcano b. high-silica-content magma c. an explosive eruption d. caldera formation

a. a submarine volcano

Which of the following earthquake phenomena is the least likely to actually injure or kill humans? Select one: a. ground shaking b. landslides and avalanches c. sediment liquefaction d. tsunami

a. ground shaking

Which of the following does NOT describe a structural feature of a volcano? Select one: a. vent b. vesicle c. fissure d. magma chamber

b. vesicle

Which term does NOT denote a pattern of motion of the Earth during an earthquake? Select one: a. foreshocks b. aftershocks c. InSAR d. elastic rebound

c. InSAR

If you see small, angular fragments of shattered rock along a linear boundary between two masses of rock, you must be looking at: Select one: a. fault gouge. b. slickensides. c. fault breccia. d. mylonites.

c. fault breccia.

Identify the FALSE statement. Lava of low viscosity: Select one: a. could logically build a shield volcano. b. indicates an area that has little potential for explosive eruptions. c. is most often a "cool" temperature lava. d. has low silica content.

c. is most often a "cool" temperature lava.

Which of the following is NOT a form of lava? Select one: a. a'a' b. pahoehoe c. blocky d. lapilli

d. lapilli

Which of the following volcanic areas is NOT part of the Ring of Fire? Select one: a. Iceland b. Aleutians, Alaska c. Cascades, northwest United States d. Mt. Pinatubo, Philippines

a. Iceland

Which statement is TRUE? Select one: a. R- and L-waves are surface seismic waves. b. S-waves are compressional body waves; P-waves are shear body waves. c. Surface waves are the first to show up on a seismogram recording of a quake. d. Shallow-focus quakes do less damage than deep-focus quakes.

a. R- and L-waves are surface seismic waves

Which statement concerning tsunami events is FALSE? Select one: a. The velocity of a tsunami wave increases when the wave moves from open ocean into shallower water. b. Tsunamis may be generated by underwater earthquakes, landslides in coastal mountain ranges, or submarine landslides. c. The interval between waves varies from about 15 minutes to an hour, and wave action may continue for several hours. d. Tsunamis can travel as fast as jet planes (several hundred mph).

a. The velocity of a tsunami wave increases when the wave moves from open ocean into shallower water.

Plinean eruptions: Select one: a. are highly explosive and can destroy the original shape of the volcano. b. occur in Hawaii where successive eruptions build up layers of basalt. c. produce a fountain of basaltic lapilli. d. are effusive and contain gas bubbles.

a. are highly explosive and can destroy the original shape of the volcano.

Identify the FALSE statement. Long-term earthquake predictions: Select one: a. are unreliable and do not provide useful information. b. are based on the identification of seismic zones. c. are based on the study of historic recurrence intervals. d. involve looking for sand volcanoes and disrupted bedding in the area.

a. are unreliable and do not provide useful information.

Mt. Vesuvius erupted in a very violent explosion in 79 C.E. and buried the residents of Pompeii in ash. On the basis of this information, which of the following would you LEAST expect to find at Vesuvius? Select one: a. basaltic lava b. lapilli (cinders) c. rhyolite lava d. ignimbrite

a. basaltic lava

Identify the TRUE statement. The San Andreas fault: Select one: a. is a right-lateral, strike-slip fault. b. has a fault plane that dips 120° to the southeast. c. is a planar structure, so its orientation should be expressed in terms of bearing and plunge. d. can also properly be called the San Andreas joint.

a. is a right-lateral, strike-slip fault.

Identify the FALSE statement. The eruption of Mt. Tambora, Indonesia, in 1815: Select one: a. is the only documented example of possible eruption-triggered coolness. b. resulted in extremely low temperatures in the northern hemisphere during 1816. c. produced "the year without a summer." d. produced such dreary weather it inspired the writing of Frankenstein.

a. is the only documented example of possible eruption-triggered coolness.

Which of the following volcanic phenomena can be triggered by a volcanic eruption under ice? Select one: a. jokulhlaup b. hyaloclastite c. lava dome and spine d. lava tube

a. jokulhlaup

Identify the FALSE statement. The Richter scale: Select one: a. measures the size of a quake in terms of the damage it does (its intensity). b. measures the amplitude of the largest deflection on a seismogram in response to specifically defined seismic waves at a specifically defined distance and depth. c. is today termed a local magnitude reading (ML). d. works well only for shallow, nearby earthquakes.

a. measures the size of a quake in terms of the damage it does (its intensity).

These volcanic products cover 70% of Earths surface. Select one: a. mid-ocean ridge volcanism b. hot spots c. LIPs d. flood basalts

a. mid-ocean ridge volcanism

The crust in the Basin and Range Province of Nevada, Utah, and Arizona is stretching; therefore, fault movement in this region must be: Select one: a. normal. b. shear. c. reverse. d. thrust.

a. normal.

Brittle deformation: Select one: a. occurs when many atomic bonds are broken quickly and rock pieces separate. b. is more likely to occur deep in the crust than at the surface. c. is favored by high-temperature, high-pressure conditions. d. produces folds, like anticlines.

a. occurs when many atomic bonds are broken quickly and rock pieces separate.

Identify the FALSE statement. Brittle deformation: Select one: a. produces folds and faults. b. is a permanent change of shape; elastic strain is a temporary change of shape. c. occurs above the brittle-ductile transition zone. d. deformation rates may change during the course of an orogeny.

a. produces folds and faults.

Which of the following is NOT a good technique for building earthquake-resistant structures? Select one: a. use concrete-block rather than wood-frame construction. b. bolt bridge spans to the top of support columns. c. wrap bridge supports with steel cables. d. use supports that are capable of holding more than the static (unmoving) weight of the building.

a. use concrete-block rather than wood-frame construction.

Identify the FALSE statement. Select one: a. Normal faults result from stretching the Earth's crust; thrust faults from squeezing and shortening it. b. ML, mb, and Ms earthquake magnitude scales can accurately define extremely large earthquakes. c. Moment magnitude (Mw) rating is the number now used for the official (archival) record. d. All earthquake magnitude scales are logarithmic, which means a difference of one unit in magnitude reading represents a 10-fold difference in ground motion.

b. ML, mb, and Ms earthquake magnitude scales can accurately define extremely large earthquakes.

Which of the following statements is FALSE? Select one: a. Major mountain ranges are the result of multiple orogenies over long geologic time. b. Mountains continue to get higher as long as the rate of erosion equals the rate of uplift. c. Domes and basins in the midwestern United States are the result of epeirogeny. d. Fault-block mountains result when blocks of crust drop downward along normal faults.

b. Mountains continue to get higher as long as the rate of erosion equals the rate of uplift.

This stratovolcano recently erupted in the United States. Although it warned of its impending eruption, it still killed people, partly because it first blew sideways and produced a monstrous landslide. The volcano is: Select one: a. Surtsey. b. Mt. St. Helens. c. Mt. Ranier. d. Yellowstone.

b. Mt. St. Helens

Identify the FALSE statement. Volcanic gases: Select one: a. are more abundant in felsic lavas than mafic lavas. b. are not harmful because most are less dense than air. c. killed over 1,700 people at Lake Nyos, Cameroon, Africa, in 1986. d. are released by magma as it rises and the pressure decreases.

b. are not harmful because most are less dense than air.

Which of the following statements is FALSE? Mountains: Select one: a. have roots of continental crust that extend deeper than the level of crust under plains. b. are randomly distributed over Earth's surface. c. can spread laterally under their own weight, given time. d. are created during orogenies that may last for millions of years.

b. are randomly distributed over Earth's surface.

The locations of major earthquakes and volcanic eruptions: Select one: a. are not similar to each other. b. are usually along plate boundaries. c. are usually toward the centers of tectonic plates. d. always mark places where plates are converging, never where they're diverging.

b. are usually along plate boundaries.

Identify the FALSE statement. Fault creep: Select one: a. is slow but steady movement along a fault. b. causes additional buildup of stress in an area, thereby increasing the likelihood that a strong quake will happen there soon. c. may be happening in seismic gaps. d. may happen because the rock is weak and can slip smoothly, without creating shock waves.

b. causes additional buildup of stress in an area, thereby increasing the likelihood that a strong quake will happen there soon

A moving, glowing cloud of hot gases and volcanic pieces: Select one: a. was named with a Hawaiian term because it's so common there. b. is called a pyroclastic flow or nuée ardent c. is so rare, none occurred last century. d. is associated with shield volcanoes.

b. is called a pyroclastic flow or nuée ardent

When the buoyancy force pushing up on lithosphere equals the gravitational force pulling down on it, the situation is said to show: Select one: a. detachment. b. isostatic equilibrium. c. orogenic collapse. d. epeirogeny.

b. isostatic equilibrium.

Identify the FALSE statement. Seismographs: Select one: a. may be the mechanical type, consisting of a weight, spring, frame, pen, and revolving cylinder. b. may be electronic, consisting of a heavy cylindrical magnet, coil of wire, spring, and computer readout of the voltage generated. c. are only sensitive enough to record ground movements down to about 1 mm. d. operate because of inertia; one part of the instrument remains motionless while the recording device moves in response to seismic waves.

b. may be electronic, consisting of a heavy cylindrical magnet, coil of wire, spring, and computer readout of the voltage generated.

Which of the following is NOT a way to recognize faults in the field? Select one: a. a displaced marker bed, such as an ash layer b. mineral-filled veins c. slip lineations on a fault plane d. an offset stream channel

b. mineral-filled veins

Lava is: Select one: a. always produced during any volcanic activity. b. molten rock that cools and hardens on Earth's surface. c. all the same chemical composition, whether it's rhyolite or basalt. d. the most life-threatening volcanic product of any eruption.

b. molten rock that cools and hardens on Earth's surface.

Which of the following conditions will tend to make rocks change by ductile deformation rather than by brittle deformation? Select one: a. cool surroundings b. slowly applied stress c. position fairly close to Earth's surface d. granitic composition

b. slowly applied stress

Identify the structure that makes this pattern of rock layers on the ground surface: parallel stripes, showing bilateral symmetry across a mid-line (hinge), with rock getting older as you move outward from the hinge. Select one: a. anticline b. syncline c. plunging fold d. monocline

b. syncline

A horizontal line on Earth's surface has a plunge of: Select one: a. 90? b. 45? c. 0? d. greater than 120?.

c. 0?

Examining sedimentary bedding in a geologic study reveals disrupted layers formed 260, 820, 1,200, 2,100, and 2,300 years ago. What is the recurrence interval of the earthquakes that caused the disruption? Select one: a. 200 years b. 380 years c. 510 years d. 560 years

c. 510 years

Which statement is TRUE? Select one: a. P, S, L, and R are all body waves that pass through the Earth's interior. b. The hypocenter (focus) is the point on Earth's surface directly above the epicenter. c. Governments are supportive of the worldwide seismic network because it can detect nuclear bomb tests as well as natural earthquakes. d. S-waves travel twice as fast as P-waves.

c. Governments are supportive of the worldwide seismic network because it can detect nuclear bomb tests as well as natural earthquakes.

Identify the FALSE statement: Select one: a. Epeirogenic movements affect broader areas and produce more gently sloping structures than do orogenic processes. b. Erosion wears down mountains, and mountains collapse under their own weight. c. If you walk from the outer edge of a dome in toward its center, you cross progressively younger rock layers. d. The youngest rocks of a basin are found at its center.

c. If you walk from the outer edge of a dome in toward its center, you cross progressively younger rock layers.

Mt. St. Helens erupted explosively in 1980. Geologists find evidence of many eruptions of St. Helens, dating back 37,000 years. The mountain is huge and is composed of layers of lava and pyroclastics. Which of the following is therefore most likely TRUE? Select one: a. When lava flows from Mt. St. Helens, it will be basalt. b. The volcano is extinct. c. Mt. St. Helens is a stratovolcano (or composite volcano). d. Mt. St. Helens sits on a transform-plate boundary.

c. Mt. St. Helens is a stratovolcano (or composite volcano).

Which of the following statements is FALSE regarding the 2010 Haiti earthquake? Select one: a. The event was so destructive because of poor construction standards. b. Faulting occurred along a transform-plate boundary between the Caribbean and North American plates. c. The earthquake generated a tsunami that was responsible for the majority of the lives lost. d. The likelihood of an earthquake was great because stress had been building on the fault for over 200 years.

c. The earthquake generated a tsunami that was responsible for the majority of the lives lost.

Which of the following is NOT considered a warning sign of imminent eruption? Select one: a. earthquake activity b. change in heat flow from the volcano's surface c. a period of quiescence in the volcano's activity d. increase in gas emissions and hydrothermal activities

c. a period of quiescence in the volcano's activity

In the 1990s, a California camper in a volcanic area died after he ignored posted warnings and slept in a campground among standing but dead trees. He was not scalded, he was not poisoned, and the campground did not smell bad. What volcanic gas killed the camper and the trees? Select one: a. water vapor b. sulfur dioxide c. carbon dioxide d. hydrogen sulfide

c. carbon dioxide

Which statement is FALSE? Liquefaction: Select one: a. can cause clay-rich sediment to turn into an unstable slurry of clay and water. b. is the sudden loss of strength of some soils that happens because of earthquake shaking. c. caused the greatest amount of damage in the San Francisco quake of 1908. d. can affect sand layers below ground surface and cause them to erupt as sand volcanoes or sand boils.

c. caused the greatest amount of damage in the San Francisco quake of 1908.

Which of the following terms is not associated with the process of mountain building? Select one: a. orogeny b. tectonic foliation c. cratonic platform d. brittle and ductile deformation

c. cratonic platform

Stress: Select one: a. is the change in shape produced by strain. b. is the same as force. c. developed during orogeny can be different at various locations. d. created by plate collision is the same everywhere and reflects the total force produced by the interacting plates.

c. developed during orogeny can be different at various locations.

Which of the following statements is FALSE? The East African Rift Valley: Select one: a. is basically a long graben. b. is bordered by linear mountain ranges called fault-block mountains. c. is produced by compressional stress. d. has volcanoes along it because asthenosphere is rising under the rift and supplying heat.

c. is produced by compressional stress.

Identify the FALSE statement. Rhyolite lava: Select one: a. has more silica than basalt lava does. b. indicates the tendency for explosive activity. c. may be squeezed upward and out of the vent to create a lava fountain. d. may form a lava dome above the vent.

c. may be squeezed upward and out of the vent to create a lava fountain.

You're looking at a fault trace in the field. You observe a polished surface, with linear grooves on it, and fine powder along it. In more technical terms, what are you seeing? Select one: a. shear zone, fault gouge, and fault breccia b. slip lineation, slickensides, and mylonites c. slickensides, slip lineations, and fault gouge d. slickensides, mylonites, and fault gouge

c. slickensides, slip lineations, and fault gouge

Identify the FALSE statement. Plate tectonics theory explains why volcanic activity occurs where it does. For example: Select one: a. active volcanoes in east Africa and extinct volcanoes of the Basin and Range Province of Nevada are the result of rifting (divergence) in continental crust. b. rifting above a plume produced flood basalts such as the Columbia River Plateau of Washington and Oregon and the Deccan Plateau of India. c. the volcanoes of Iceland owe their existence to the mantle plume underlying the convergent-plate boundary on which they sit. d. the Ring of Fire bordering much of the Pacific Ocean is a long chain of subduction-zone volcanoes.

c. the volcanoes of Iceland owe their existence to the mantle plume underlying the convergent-plate boundary on which they sit.

Identify the FALSE statement. Mountains don't get infinitely high or exist forever because: Select one: a. erosion is a constant force acting to wear mountains down. b. their own weight causes them eventually to collapse. c. they are eventually subducted in the plate tectonic cycle. d. they experience orogenic collapse.

c. they are eventually subducted in the plate tectonic cycle.

Which of the following statements is FALSE? Select one: a. In a dip-slip fault, movement along the fault plane is vertical. b. In a strike-slip fault, movement along the fault plane is horizontal. c. In an oblique fault, there's both vertical and horizontal movement along the fault plane. d. A thrust fault is a reverse fault with an extremely high dip (close to 90°).

d. A thrust fault is a reverse fault with an extremely high dip (close to 90°).

Identify the FALSE statement. Select one: a. Seismic waves become smaller in amplitude with increasing distance from the epicenter. b. Earthquake magnitude is based on ground motion recorded by a seismograph; intensity is based on the amount of damage produced. c. Contour lines representing Mercalli values are used to delimit zones of quake intensity; the greater the quake, the higher the intensity values and the wider the zones. d. Earthquakes never have hypocenters (foci) deeper than about 100 km (60 miles).

d. Earthquakes never have hypocenters (foci) deeper than about 100 km (60 miles).

Identify the TRUE statement. Select one: a. The variety of different wave frequencies (the frequency content) of an earthquake remains the same with distance from the hypocenter. b. Low-frequency seismic waves cause more ground acceleration than do high-frequency waves. c. Low frequency waves lose energy more rapidly than high-frequency waves. d. In the Mexico City quake, high-frequency waves weakened with distance, but unconsolidated

d. In the Mexico City quake, high-frequency waves weakened with distance, but unconsolidated

Which of the following explosive eruptions was enhanced by seawater flooding the magma chamber? Select one: a. Mt. St. Helens, Washington, 1980 b. Mt. Vesuvius, Italy, 79 C.E. c. The Big Island, Hawaii, currently erupting d. Krakatau, Indonesia, 1883

d. Krakatau, Indonesia, 1883

A lahar is: Select one: a. a glowing cloud of pyroclastic fragments and hot gas. b. a lava lake in a summit crater. c. a collapsed volcanic structure. d. a volcanic mud flow that resembles fluid concrete.

d. a volcanic mud flow that resembles fluid concrete.

Identify the FALSE statement. The tsunami event of Dec. 26, 2004: Select one: a. involved a monstrous magnitude 9.3 earthquake that lasted 9 minutes. b. was first noticed as a withdrawal of the sea along the beach front. c. consisted of local tsunamis that affected the island of Sumatra and later distant tsunamis that struck all along the Indian Ocean coast. d. could have resulted in an even greater death toll but for the timely warnings issued immediately after the quake.

d. could have resulted in an even greater death toll but for the timely warnings issued immediately after the quake.

Identify the FALSE statement. Short-term earthquake prediction: Select one: a. is being worked on but is far from being a successful procedure. b. may involve interpretation of swarms of foreshocks. c. may involve precise laser survey of the ground, looking for small distortions. d. depends heavily on studying precursor phenomena like changes in water level in wells, gases, electrical conduction of rock, and animal behavior.

d. depends heavily on studying precursor phenomena like changes in water level in wells, gases, electrical conduction of rock, and animal behavior.

Identify the FALSE statement. A shield: Select one: a. is part of a craton. b. contains Precambrian metamorphic and igneous rocks outcropping at ground surface. c. can be associated with a cratonic platform. d. has layers of undeformed sedimentary rock that are extremely old.

d. has layers of undeformed sedimentary rock that are extremely old.

Lahars, composed of ash, debris, and water: Select one: a. occur only in arctic regions because snow supplies the water for mud. b. are extremely rare. c. are called nuée ardents. d. have often resulted in damage and death to humans and their property.

d. have often resulted in damage and death to humans and their property.

A tsunami: Select one: a. is a special kind of tidal wave caused by the gravitational attraction of the Sun not the Moon. b. can get big but never bigger than 30 feet high. c. is dangerous near its source but dies out within about 200 miles. d. may be just a broad, gentle swelling out at sea but grows as it approaches shore.

d. may be just a broad, gentle swelling out at sea but grows as it approaches shore.

Earthquake prediction is not highly reliable, but geologists do know: Select one: a. quakes will never happen in seismic gaps. b. that recurrence intervals can provide accurate short-term predictions. c. northern California, not southern California, is the area most likely to have the "Big One." d. more earthquakes happen along plate boundaries than happen at intraplate locations.

d. more earthquakes happen along plate boundaries than happen at intraplate locations.

Which statement is TRUE? Earthquakes in California are: Select one: a. the result of reverse faulting along the San Andreas Fault. b. the result of widening along the San Andreas Fault, which will eventually cause western California to sink into the ocean. c. always above magnitude 7.5 because the San Andreas is such a large fault. d. shallow and occur in the upper 15 km of crust, even though the San Andreas fault cuts through the crust to deeper depths.

d. shallow and occur in the upper 15 km of crust, even though the San Andreas fault cuts through the crust to deeper depths

The Badlands of South Dakota are elevated, eroded plateaus and valleys composed of undeformed sedimentary strata. These aren't mountains because: Select one: a. they're not old enough. b. they consist of sedimentary rocks. c. they're not high enough. d. there's no deformation of rocks or structures.

d. there's no deformation of rocks or structures.

A high-pressure, fast-moving (>300 km/hr) mixture of pyroclastic debris including fragments and gas typically ejected vertically from a volcanic vent is called: Select one: a. a lahar. b. a plinian column. c. Pele's hair. d. an ignimbrite.

b. a plinian column.