part 1
Chapter 1: The Water Planet
Chapter 1: Quick Review Questions
1.1 Cosmic Beginnings
1. The universe formed roughly 13.8 billion years ago in an event we call the Big Bang.
The Big Bang model of formation postulates that all energy and matter in the
universe was initially concentrated in an extremely hot, dense singularity smaller
than an atom. This singularity experienced a cataclysmic explosion that caused the
universe to expand rapidly and cool.
2. Our solar system formed as a result of the collapse of a rotating interstellar cloud of
gas and dust called a nebula. This occurred roughly 5 billion years ago.
3. Heat was added to the early Earth’s interior by three processes: 1) as particles of all
sizes bombarded the planet and a portion of their energy was converted to heat on
impact, 2) the growing size of Earth compressed the interior, and 3) the decay of
radioactive elements released heat. When the temperature was high enough to melt
iron and nickel, they migrated to Earth’s center and lighter elements migrated
toward the surface.
4. Sources of the early oceans and atmosphere include: 1) the release of water,
hydrogen, and oxygen during the heating and differentiation of the planet with
associated volcanic activity, and 2) water added by comet-like balls of ice or ice
meteorites that have collided with Earth through time.
1.2 Earth’s Age and Time
1. Earth is approximately 4.5 to 4.6 billion years old.
2. Estimates of Earth’s age have changed over the past few hundreds of years as the
methods used to estimate it have changed. Early estimates were not based on
scientific processes. Later scientific methods were based on incomplete information.
The current estimate of Earth’s age is based on radiometric dating that has been
repeatedly tested. It is unlikely that the estimate of Earth’s age will change
significantly in the future.
3. Rocks are dated by measuring the relative abundance of radioactive isotopes in
them.
4. After two half-lives, 25% of the original parent isotope would be left.
5. The appearance or disappearance of fossil types was used to set the boundaries of
geologic time units before radiometric dating.
6. This is because Earth’s axis of rotation is tilted 23.5˚ with respect to the plane of its
orbit around the Sun.
1
© McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.
,1.3 Earth’s Shape
1. Earth’s shape is nearly spherical. It is actually an oblate spheroid, slightly flattened
at the poles and bulging at the equator.
2. Earth isn’t a perfect sphere because it is not completely rigid. Earth’s rotation causes
it to bulge at the equator and flatten at the poles.
3. Given Earth’s size, the difference in elevation from the highest mountain to the
deepest ocean depth is relatively small. Consequently, Earth’s surface can be
thought of as very smooth.
1.4 Where on Earth are You?
1. This is a mechanical exercise for students.
2. Circles of latitude vary in diameter with distance from the equator. The equator is
the only circle of latitude with a unique diameter. It’s diameter is larger than any
other circle of latitude. The prime meridian is one half the circumference of a circle
of longitude. All circles of longitude are the same diameter so the choice of the prime
meridian is arbitrary.
3. This is because Earth’s axis of rotation is tilted 23.5˚ with respect to the plane of its
orbit around the Sun.
4. Time and longitude are directly related because Earth rotates through 15˚ of
longitude in one hour of time.
5. We will not always be able to use the North Star to determine latitude in the North
Hemisphere because Earth’s axis of rotation rotates very slowly, making one
complete revolution in about 26,000 years. Consequently, it does not always point
directly to the North Star.
6. Latitude and Longitude for the following cities:
City Latitude Longitude
Chicago, IL 41.85˚N 87.65˚W
Montreal, Canada 45.51˚N 73.55˚W
Buenos Aires, Argentina 34.60˚S 58.38˚W
London, England 51.52˚N 0.11˚W
Vienna, Austria 48.21˚N 16.37˚E
Peking, China 39.91˚N 116.40˚E
Tokyo, Japan 35.68˚N 139.77˚E
Cape Town, South 33.98˚S 18.42˚E
Africa
Nairobi, Kenya 1.28˚S 36.82˚E
Canberra, Australia 35.28˚S 149.13˚E
Papeete, Tahiti 17.53˚S 149.57˚W
2
© McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.
,1.5 Modern Navigation
(No questions)
1.6 Earth is a Water Planet
1. Water cycles through the entire planetary environment. Balanced inputs and
outputs of water can only be assured for Earth as a whole, not for subregions.
2. Climate zones have distinct temperature and moisture characteristics. These
characteristics have a major influence on rates of evaporation and precipitation so
water moves through reservoirs at different rates in different climate zones.
3. Two example routes are: 1) mountain lake-atmosphere (evaporation), atmosphere-
ocean (precipitation), and 2) mountain lake-groundwater (infiltration),
groundwater-ocean (underground flow). The water would spend the least time in
the atmosphere and the longest time as groundwater.
4. Earth’s surface is 71% water and 29% land.
5. There is more Earth surface area covered by water in the Southern Hemisphere than
in the Northern Hemisphere. There is more Earth surface area covered by land in
the Northern Hemisphere than in the Southern Hemisphere.
6. Roughly 80% of land is at an elevation below 2 km while about 85% of the ocean
floor is at a depth greater than 2 km.
7. Pacific, Atlantic, Indian, Southern, Arctic.
3
© McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.
, Chapter 2: Earth Structure and Plate
Tectonics
Chapter 2: Quick Review Questions
2.1 Earth’s Interior
1. P-waves travel through solids, liquids, and gases. S-waves travel through solids.
2. Continental crust is composed largely of granite with an average density of
2.7 g/cm3 and an average thickness of 40 km. Oceanic crust is composed largely of
basalt with an average density of 2.9 g/cm3 and an average thickness of 7 km.
3. The Moho is the boundary between the crust and the mantle. It is deeper under the
continents because continental crust is generally thicker than oceanic crust.
4. (a) The crust and mantle are layers that differ from one another in chemical
composition. (b) The lithosphere, asthenosphere, and mesosphere are layers that
differ from one another in rigidity.
5. Because of isostatic equilibrium.
6. The outer core an inner core are similar because they have the same chemistry. The
outer core and inner core are different because they are in different physical states.
The outer core behaves like a liquid and the inner core is solid.
2.2 History of a Theory: Continental Drift
1. Wegener used a variety of different kinds of evidence in proposing his theory of
drifting continents. These included the geographic fit of continents, and several
different features that can be found on different continents now but that fit together
when the continents are joined such as: patterns of fossil plants and animals;
mountain ranges of similar age, structure, and composition; unusual sequences of
rocks and rock units; and patterns of glaciation.
2. Pangaea included all modern land masses.
3. Laurasia included North America and Eurasia. Gondwanaland included Africa, South
America, India, Australia, and Antarctica.
4. The primary objection was the lack of a plausible driving mechanism.
1
© McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.
Chapter 1: The Water Planet
Chapter 1: Quick Review Questions
1.1 Cosmic Beginnings
1. The universe formed roughly 13.8 billion years ago in an event we call the Big Bang.
The Big Bang model of formation postulates that all energy and matter in the
universe was initially concentrated in an extremely hot, dense singularity smaller
than an atom. This singularity experienced a cataclysmic explosion that caused the
universe to expand rapidly and cool.
2. Our solar system formed as a result of the collapse of a rotating interstellar cloud of
gas and dust called a nebula. This occurred roughly 5 billion years ago.
3. Heat was added to the early Earth’s interior by three processes: 1) as particles of all
sizes bombarded the planet and a portion of their energy was converted to heat on
impact, 2) the growing size of Earth compressed the interior, and 3) the decay of
radioactive elements released heat. When the temperature was high enough to melt
iron and nickel, they migrated to Earth’s center and lighter elements migrated
toward the surface.
4. Sources of the early oceans and atmosphere include: 1) the release of water,
hydrogen, and oxygen during the heating and differentiation of the planet with
associated volcanic activity, and 2) water added by comet-like balls of ice or ice
meteorites that have collided with Earth through time.
1.2 Earth’s Age and Time
1. Earth is approximately 4.5 to 4.6 billion years old.
2. Estimates of Earth’s age have changed over the past few hundreds of years as the
methods used to estimate it have changed. Early estimates were not based on
scientific processes. Later scientific methods were based on incomplete information.
The current estimate of Earth’s age is based on radiometric dating that has been
repeatedly tested. It is unlikely that the estimate of Earth’s age will change
significantly in the future.
3. Rocks are dated by measuring the relative abundance of radioactive isotopes in
them.
4. After two half-lives, 25% of the original parent isotope would be left.
5. The appearance or disappearance of fossil types was used to set the boundaries of
geologic time units before radiometric dating.
6. This is because Earth’s axis of rotation is tilted 23.5˚ with respect to the plane of its
orbit around the Sun.
1
© McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.
,1.3 Earth’s Shape
1. Earth’s shape is nearly spherical. It is actually an oblate spheroid, slightly flattened
at the poles and bulging at the equator.
2. Earth isn’t a perfect sphere because it is not completely rigid. Earth’s rotation causes
it to bulge at the equator and flatten at the poles.
3. Given Earth’s size, the difference in elevation from the highest mountain to the
deepest ocean depth is relatively small. Consequently, Earth’s surface can be
thought of as very smooth.
1.4 Where on Earth are You?
1. This is a mechanical exercise for students.
2. Circles of latitude vary in diameter with distance from the equator. The equator is
the only circle of latitude with a unique diameter. It’s diameter is larger than any
other circle of latitude. The prime meridian is one half the circumference of a circle
of longitude. All circles of longitude are the same diameter so the choice of the prime
meridian is arbitrary.
3. This is because Earth’s axis of rotation is tilted 23.5˚ with respect to the plane of its
orbit around the Sun.
4. Time and longitude are directly related because Earth rotates through 15˚ of
longitude in one hour of time.
5. We will not always be able to use the North Star to determine latitude in the North
Hemisphere because Earth’s axis of rotation rotates very slowly, making one
complete revolution in about 26,000 years. Consequently, it does not always point
directly to the North Star.
6. Latitude and Longitude for the following cities:
City Latitude Longitude
Chicago, IL 41.85˚N 87.65˚W
Montreal, Canada 45.51˚N 73.55˚W
Buenos Aires, Argentina 34.60˚S 58.38˚W
London, England 51.52˚N 0.11˚W
Vienna, Austria 48.21˚N 16.37˚E
Peking, China 39.91˚N 116.40˚E
Tokyo, Japan 35.68˚N 139.77˚E
Cape Town, South 33.98˚S 18.42˚E
Africa
Nairobi, Kenya 1.28˚S 36.82˚E
Canberra, Australia 35.28˚S 149.13˚E
Papeete, Tahiti 17.53˚S 149.57˚W
2
© McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.
,1.5 Modern Navigation
(No questions)
1.6 Earth is a Water Planet
1. Water cycles through the entire planetary environment. Balanced inputs and
outputs of water can only be assured for Earth as a whole, not for subregions.
2. Climate zones have distinct temperature and moisture characteristics. These
characteristics have a major influence on rates of evaporation and precipitation so
water moves through reservoirs at different rates in different climate zones.
3. Two example routes are: 1) mountain lake-atmosphere (evaporation), atmosphere-
ocean (precipitation), and 2) mountain lake-groundwater (infiltration),
groundwater-ocean (underground flow). The water would spend the least time in
the atmosphere and the longest time as groundwater.
4. Earth’s surface is 71% water and 29% land.
5. There is more Earth surface area covered by water in the Southern Hemisphere than
in the Northern Hemisphere. There is more Earth surface area covered by land in
the Northern Hemisphere than in the Southern Hemisphere.
6. Roughly 80% of land is at an elevation below 2 km while about 85% of the ocean
floor is at a depth greater than 2 km.
7. Pacific, Atlantic, Indian, Southern, Arctic.
3
© McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.
, Chapter 2: Earth Structure and Plate
Tectonics
Chapter 2: Quick Review Questions
2.1 Earth’s Interior
1. P-waves travel through solids, liquids, and gases. S-waves travel through solids.
2. Continental crust is composed largely of granite with an average density of
2.7 g/cm3 and an average thickness of 40 km. Oceanic crust is composed largely of
basalt with an average density of 2.9 g/cm3 and an average thickness of 7 km.
3. The Moho is the boundary between the crust and the mantle. It is deeper under the
continents because continental crust is generally thicker than oceanic crust.
4. (a) The crust and mantle are layers that differ from one another in chemical
composition. (b) The lithosphere, asthenosphere, and mesosphere are layers that
differ from one another in rigidity.
5. Because of isostatic equilibrium.
6. The outer core an inner core are similar because they have the same chemistry. The
outer core and inner core are different because they are in different physical states.
The outer core behaves like a liquid and the inner core is solid.
2.2 History of a Theory: Continental Drift
1. Wegener used a variety of different kinds of evidence in proposing his theory of
drifting continents. These included the geographic fit of continents, and several
different features that can be found on different continents now but that fit together
when the continents are joined such as: patterns of fossil plants and animals;
mountain ranges of similar age, structure, and composition; unusual sequences of
rocks and rock units; and patterns of glaciation.
2. Pangaea included all modern land masses.
3. Laurasia included North America and Eurasia. Gondwanaland included Africa, South
America, India, Australia, and Antarctica.
4. The primary objection was the lack of a plausible driving mechanism.
1
© McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.
