Geosystems: An Introduction to Physical Geography, 9e (Christopherson)
Chapter 12 The Dynamic Planet
12.1 Multiple Choice Questions
1) Which of the following is incorrectly matched?
A) endogenic — internal processes
B) exogenic — external processes
C) radioactive decay heat — exogenic energy source
D) weathering — exogenic breaking and dissolving the crust
2) The subfield of geography and geology concerned with the study of the origins, evolutions,
form, and spatial distribution of the Earth’s landforms is
A) geophysics.
B) lithology.
C) geomorphology.
D) Pedology.
3) Which of the following is an endogenic process?
A) weathering
B) stream deposition
C) volcanism
D) glacial erosion
4) Which of the following is an exogenic process?
A) earthquakes
B) volcanism
C) flows of heat and materials in the mantle
D) weathering
5) Which of the following plays a role in the shaping of Earth’s surface?
A) gravity
B) the action of wind, water, and ice
C) the radioactive decay of atoms
D) gravity, wind, water, and ice, and radioactive decay
E) gravity and wind, water, and ice only
6) Tectonic forces are an example of
A) exogenic processes.
B) endogenic processes.
C) both exogenic and endogenic processes.
D) neither exogenic nor endogenic processes.
7) Earth’s magnetic poles
A) are fixed.
B) are migrating approximately 55 to 60 km (34 to 37 mi) per year.
C) are perfectly aligned with Earth’s axis.
D) are misaligned from Earth’s axis by 23.5 degrees.
8) The principle that the same physical processes currently active in the environment were
operating throughout Earth’s history is known as
A) uniformitarianism.
B) catastrophism.
C) parallelism.
D) statis.
9) Uniformitarianism assumes that
A) Earth is quite young and is shaped by dramatic events.
B) catastrophic episodes have regularly occurred.
C) the same physical processes we see today are a key to understanding the processes that have
been operating throughout geologic time.
D) mountains, plains, and canyons formed by catastrophic events.
10) Which of the following is an example of the principle of uniformitarianism?
A) It is not possible to know how Earth processes have changed overtime, therefore it is not
possible to deduce how Earth’s ancient landforms evolved.
B) The processes by which streams carve valleys at present are the same as those that carved
valleys 500 millions years ago.
C) Catastrophic events, such as major landslides, earthquakes, and volcanic episodes, are the
primary drivers of geomorphological change.
D) The Earth’s geological history is mostly uniform and homogenous, existing now as it mostly
always has with the exception of minor recent changes.
11) When geologists conclude that the Grand Canyon sequence of rocks was formed through
hundreds of millions of years of deposition, mountain building, and erosion, they are basing this
conclusion on the principle of ________ which states that ________.
A) catastrophism; most rock formations were created as a result of supernatural processes
B) catastrophism; a single, large flood was responsible for the creation of the rock sequence
C) uniformitarianism; all geologic processes take immense amounts of time to occur and always
occur at the same rate
D) uniformitarianism; the geologic processes that operated in the past are the same as those that
operate today, and they occurred in accordance with the same laws of nature that are operating
today
12)
Which of the following is correct regarding the geologic time scale?
A) The Jurassic period occurred during the Paleozoic era.
B) Over 87 percent of Earth’s history has elapsed during the more recent Cenozoic, Mesozoic,
and Paleozoic eras.
C) The bulk of Earth’s history has occurred during the Precambrian eon.
D) We live in the Tertiary period.
13)
The Precambrian Eon encompasses what percentage of Earth’s total history?
A) 0.04 %
B) 5%
C) 11.7%
D) 88.3%
14) Boundaries between intervals of the geological time scale are determined by
A) dividing the time range of the interval by the number desired subdivisions, thereby creating
equal intervals between the divisions.
B) Major events in the Earth’s history, such as major extinctions.
C) using a quantile method whereby the number of years in each subdivision is determined by
dividing the number of years by the desired number of classes.
D) Climatic periods based on paleoclimatological reconstructions.
15) Which of the following is an example of an age-relationship based on relative dating?
A) Australopithecines were alive 3.2 million years ago.
B) The Neanderthals became extinct 35,000 years ago.
C) Australopithecines evolved before Homo erectus.
D) Clovis points have been dated at 11,000 years old in North America.
16) Which of the following is not an example of an age-relationship based on absolute dating?
A) The oldest known rocks on Earth are 3.96 billion years old.
B) The Vishnu schist at the bottom of the Grand Canyon is 2 billion years old.
C) The dinosaurs became extinct 65 million years ago.
D) The Coconino formation in the Grand Canyon is older than the Kaibab formation.
17) The scientific study of rock strata (layers) is known as ________ and based on the principle
of ________.
A) stratigraphy; superposition
B) geomorpholy; uniformitarianism
C) Paleontology; catostrophism
D) Paleogeography; plate tectonics
18) Which of the following is correct in regards to the geologic time scale?
A) An epoch is composed of one or more periods.
B) The largest defined unit is an eon or, according to some, a supereon.
C) An era is the smallest unit of geologic time.
D) Every period is composed of 2 epochs.
19) In terms of dating of specific rocks, structures, or landscapes, relative age refers to
A) the age of geological features based on isotopic dating techniques.
B) the approximate age of geological features based on the period or epoch in which they
occurred. For instance, noting a feature is from the Cretaceous.
C) the inability to ascertain exact age through isotopic methods and the necessity to provide a
date range for such features.
D) the age of one feature with respect to another within a sequence of events and deduced from
the positions of rock strata above and below one another.
20) In terms of dating of specific rocks, structures, or landscapes, numerical age refers to
A) the age of geological features based on isotopic dating techniques.
B) the approximate age of geological features based on the period or epoch in which they
occurred. For instance, noting a feature is from the Cretaceous.
C) a range of numeric values in which a features was likely formed and based on several lines of
evidence, such as paleoclimatic and paleobotanical reconstructions.
D) the age of one feature with respect to another within a sequence of events and deduced from
the positions of rock strata above and below one another.
21) Scientists have direct evidence of the Earth’s structure to
A) the inner core.
B) the upper mantle (~250 km (155 mi)).
C) about 2 km (1.2 mi) from the surface.
D) 10 km (6 mi) from the surface, based on the deepest well shaft.
22) Knowledge of Earth’s interior is mostly derived from
A) direct sampling of the interior using deep-test wells.
B) work in Earth’s deepest caverns and caves.
C) indirect evidence involving the analysis of seismic waves.
D) historic and prehistoric records.
23) The fact that Earth’s interior is sorted into layers indicates that
A) the process of formation from a nebula (by the slamming together of material and
planetesimals that stuck together on impact) produces nice, neat layers.
B) Earth was once in a molten state, during which materials became sorted based on density.
C) the rotation of the early Earth acted like a centrifuge which separated materials based on
weight.
D) nothing can be inferred about such a perplexing level of organization.
24) Earth’s interior is layered because
A) centrifugal force separated out the materials based on weight as the Earth solidified.
B) materials became sorted based on density as the Earth solidified.
C) materials became sorted based on electromagnetic fields as the Earth solidified.
25) Which of the following gives the correct sequence of layers in Earth, from the surface to the
center?
A) crust, inner core, mantle, outer core
B) inner core, outer core, mantle, crust
C) mantle, crust, inner core, outer core
D) crust, mantle, outer core, inner core
26) Which of the following can occur when seismic waves encounter a layer in Earth’s interior?
A) reflection and/or refraction
B) absorption
C) change in speed
D) reflection, refraction, absorption, and change in speed.
E) seismic waves cannot penetrate below the crust of Earth
27) Which of the following is incorrect regarding Earth’s inner core?
A) It has a density of 13.5 grams/cm3.
B) It is solid iron in composition.
C) It is the source of Earth’s magnetic field.
D) It is about 1230 km (760 mi.) thick.
28) Which of the following statements about Earth’s core is not correct?
A) It is composed primarily of iron.
B) The inner core is believed to be liquid and the outer core solid.
C) Scientists think the inner core formed before the outer core.
D) A third of the Earth’s entire mass, but only 1/6th of its volume lies in its core.
29) Which layer of the planet forms 80 percent of Earth’s total volume, and has an average
density of 4.5 grams/cm3?
A) continental crust
B) oceanic crust
C) mantle
D) core
30) The boundary between the crust and the rest of the lithospheric upper mantle is a
discontinuity known as the
A) Gutenberg.
B) mantle.
C) Moho.
D) lithospheric layer.
31) The density of material below the Moho is ________ that above it.
A) greater than
B) less than
C) the same as
32) On average, the thickness of oceanic crust is ________ that of continental crust
A) greater than
B) less than
C) the same as
33) Of the elements in the Earth’s crusts, ________ makes up the most of the Earth’s crust by
weight.
A) silicon (Si)
B) aluminum (Al)
C) oxygen (O)
D) iron (Fe)
34) The percentage of oxygen is the crusts is ________ than that in the atmosphere.
A) greater than
B) less than
C) the same as
35) Which of the following is correct?
A) Continental crust is less dense than oceanic crust and composed primarily of basalt.
B) Continental crust is denser than oceanic crust and composed primarily of granite.
C) Oceanic crust is less dense than continental crust and is composed primarily of granite.
D) Oceanic crust is denser than continental crust and is composed primarily of basalt.
36) The dominant element in continental crust are
A) silica and aluminum.
B) silica and magnesium.
C) magnesium and aluminum.
D) potassium and iron.
37) The dominant element in oceanic crust are
A) silica and aluminum.
B) silica and magnesium.
C) magnesium and aluminum.
D) potassium and iron.
38) The thickness of Earth’s crust ranges from
A) 5 km to 60 km (3 mi. to 37 mi.).
B) 70 km to 250 km (43 mi. to 155 mi.).
C) the surface to an unknown depth.
D) the surface down to 2900 km (1800 mi.).
39) The aesthenosphere can best be described as
A) a rigid solid.
B) a liquid.
C) a plastic.
D) a plasma.
40) The plastic layer in the mantle from about 70 to 250 km (43 to 155 mi) in depth is known as
the
A) asthenosphere.
B) lithosphere.
C) Moho.
D) Gutenberg discontinuity.
41) The rigid crust and uppermost mantle are known collectively as the
A) asthenosphere.
B) lithosphere.
C) Moho.
D) Gutenberg discontinuity.
42) The principles of buoyancy and balance, when applied to Earth’s crust, helps us to explain
fluctuations in Earth’s outer crust, a property known as
A) magnetism.
B) Moho effect.
C) isostasy.
D) orogenesis.
43) The process of isostatic adjustment is most closely associated with which of the following?
A) lithospheric plate collisions
B) volcanic activity
C) sea-floor spreading
D) buoyancy
44) Glaciers that once covered the Hudson Bay area melted 8,000 years ago. As a result of this,
the bay is gradually rising. In another 10,000 years or so, it will have risen above sea level and
become dry. This process can best be considered an example of
A) catastrophism.
B) isostasy.
C) accretion.
D) orogenesis.
45) During the past ice age, landmasses were generally
A) pressed down into the asthenosphere by the load of ice.
B) elevated, because ice is lighter than rock.
C) unaffected by the climatic conditions of the time.
D) more exposed to the atmosphere.
46) Which of the following layers of Earth is liquid and is responsible for producing Earth’s
magnetic field?
A) inner core
B) outer core
C) lower mantle
D) aesthenosphere
47) Earth’s magnetic field
A) is variable, and it has faded to zero and returned to full strength with the polarity reversed.
B) is constant in its intensity.
C) remains a mystery as to its cause.
D) is principally generated in the inner core.
48) The average length of a period during which a given magnetic field polarity exists is about
A) 10,000 years.
B) 100,000 years.
C) 500,000 years.
D) 1,000,000 years.
49) The last pole reversal occurred ________ years ago and, based on magnetic field decay, we
are approximately ________ years from entering the next phase.
A) 1 million; 200,000
B) 20,0000; 50,000
C) 1,000; 50
D) 790,000; 1,000
50) The majority of Earth’s crust is composed of ________ rock.
A) igneous
B) metamorphic
C) sedimentary
D) carbonate
51) The uneven transition zone from the outer core to the mantle is known as the ________
discontinuity.
A) Gutenberg
B) Mohorovičić
C) Asthensosphere
D) Lithosphere
52) The majority of the Earth’s volume is within the
A) crust.
B) inner core.
C) mantle.
D) outer core.
53) The transition zone from the upper mantle to the crust is known as the ________
discontinuity.
A) Gutenberg
B) Mohorovičić
C) Asthensosphere
D) Lithosphere