Chapter 22 Shaping Earth's Surface
22.1 The Hydrologic Cycle
1) Water is vital to life on our planet. Most of Earth's water supply is in the
A) oceans.
B) ice caps.
C) rivers, lakes, and streams.
D) ground.
Answer: A
2) The driving force of our planet's hydrologic cycle comes from
A) the balance between precipitation and evaporation.
B) precipitation of water over the oceans.
C) solar energy.
D) wind.
Answer: C
3) Water precipitated over land completes its cycle as it
A) enters streams and lakes and makes its way to the oceans.
B) percolates into the ground.
C) evaporates from the surface to the atmosphere.
D) enters streams and lakes, seeps into the ground, flows to the ocean, or evaporates.
Answer: D
4) Evaporation and precipitation are greatest over the
A) polar ice caps.
B) continents.
C) oceans.
D) equator.
Answer: C
5) Evaporation and precipitation are in balance over the
A) polar ice caps.
B) continents.
C) oceans.
D) equator.
Answer: C
6) Precipitation exceeds evaporation over the
A) continents.
B) polar ice caps.
C) oceans.
D) equator.
Answer: A
7) Most of Earth's fresh water is located in
A) polar ice caps and glaciers.
B) groundwater.
C) rivers, lakes, and streams.
D) the atmosphere.
Answer: A
8) Which has the longest residence time?
A) Groundwater
B) Rivers, lakes, and streams
C) Polar ice caps and glaciers
D) Rainwater
Answer: C
9) Evaporation from the oceans produces clouds that precipitate fresh water rather than saltwater
because
A) salt is too heavy to evaporate.
B) evaporation produces nearly pure water vapor.
C) dissolved salt prevents evaporation.
D) saltwater precipitates over oceans only.
Answer: B
10) Where does most rainfall on Earth finally end up before becoming rain again?
A) Underground
B) In lakes
C) In the oceans
D) On the ground surface
Answer: C
11) Most of the world's water is in
A) icecaps.
B) glaciers.
C) rivers and lakes.
D) the oceans.
Answer: D
12) Most of Earth's accessible fresh water is located in
A) polar ice caps and glaciers.
B) groundwater.
C) rivers, lakes, and streams.
D) the atmosphere.
Answer: B
13) Evaporation from the oceans produces clouds that precipitate fresh water rather than
saltwater because
A) salt is too heavy to evaporate.
B) evaporation produces nearly pure water vapor.
C) dissolved salt prevents evaporation.
D) saltwater precipitates over oceans only.
Answer: B
14) The natural circulation of water–from ocean to air to ground to ocean and then back to the
atmosphere–is called the
A) circle of life
B) hydrologic cycle.
C) carbon cycle.
D) rock cycle.
Answer: B
15) All water–groundwater, surface water, and frozen water–flow downslope in response to
A) pressure.
B) hydraulic gradient.
C) permeability.
D) gravity.
Answer: D
16) Identify the locations of Earth's water, both oceanic and fresh.
Answer: Ninety-seven percent of Earth's water is in the oceans and about 2% is frozen in polar
ice caps and glaciers. The remaining 1% consists of water vapor in the atmosphere, water in the
ground, and water in streams and lakes.
17) What is the largest repository of fresh water?
Answer: The polar ice caps and glaciers.
22.2 Groundwater
1) Sandy soils tend to have
A) high porosity and high permeability.
B) high porosity and low permeability.
C) low porosity and low permeability.
D) low porosity and high permeability.
Answer: A
2) Water in a confined aquifer is
A) freely flowing.
B) under pressure.
C) recharge.
D) discharge.
Answer: B
3) The infiltration of water is greatest in
A) calcite-cemented sandstone.
B) sandy soil.
C) clay soil.
D) silica-cemented sandstone.
Answer: B
4) In a well in an unconfined aquifer, the highest level that water can rise to is
A) the level of the water table.
B) just below the level of the water table.
C) to the top of the well.
D) dependent on how deep the well is.
Answer: A
5) Water in the unsaturated zone is called
A) groundwater.
B) unsaturated water.
C) pore-water.
D) soil-moisture.
Answer: D
6) The dominant influence on the length of time a well will produce water is
A) hydraulic conductivity.
B) water supply and demand.
C) hydraulic gradient.
D) aquifer porosity.
Answer: B
7) As a large reservoir behind a new dam fills with water, the water table in the vicinity of the
reservoir
A) rises.
B) falls.
C) stays the same.
D) becomes unsaturated.
Answer: A
8) In an aquifer where groundwater discharges to a stream, how does the elevation of the water
table adjacent to the stream compare with the elevation of the surface of the stream?
A) The water table is lower than the surface of the stream.
B) The water table is at the same elevation as the surface of the stream.
C) The water table is higher than the surface of the stream.
D) Not enough information is given.
Answer: C
9) The flow of groundwater is
A) as fast as the water in streams.
B) from where the water table is high to where it is low.
C) from where the water table is low to where it is high.
D) insignificant.
Answer: B
10) A sub-surface region that holds and transmits water is called a/an
A) aquifer.
B) hydrometer.
C) water table.
D) aquiclude.
Answer: A
11) Groundwater is water
A) beneath the ground surface.
B) above the water table.
C) that soaks into the ground.
D) below the water table.
Answer: D
12) Where groundwater discharges to a stream, the elevation of the water table next to the stream
A) is lower than the surface of the stream.
B) is the same as the surface of the stream.
C) is higher than the surface of the stream.
D) Not enough information given
Answer: C
13) The degree to which a soil or rock allows groundwater to flow is called
A) permeability.
B) aquifer.
C) porosity.
D) hydraulic gradient.
Answer: A
14) The flow of groundwater depends on
A) permeability and porosity.
B) permeability and gravity.
C) porosity and hydraulic gradient.
D) porosity only.
Answer: B
15) The capacity a material has for transmitting fluids is known as its
A) porosity.
B) permeability.
C) competence.
D) impermeability.
Answer: B
16) A rock with very low porosity will most often have a
A) low permeability.
B) high permeability.
C) large proportion of open spaces.
D) very high density.
Answer: A
17) The poorest absorber of water is
A) sand and gravel.
B) clay.
C) rocky surfaces covered by a soil layer.
D) rocky surfaces with no soil layer.
Answer: D
18) Water able to be contained in the subsurface depends on
A) permeability.
B) porosity.
C) chemical composition.
D) none of these
Answer: B
19) A soil composed of well-rounded sand grains of uniform size will most likely have a
A) high porosity.
B) low porosity.
C) high permeability.
D) low permeability.
Answer: A
20) A soil composed of flattened soil particles will most likely have a
A) high porosity.
B) low porosity.
C) high permeability.
D) low hydraulic conductivity.
Answer: D
21) A rock with a high porosity will most likely have a
A) low permeability.
B) high permeability.
C) large proportion of open pore spaces.
D) low density.
Answer: C
22) A rock's permeability can be described by its
A) density.
B) depth of burial.
C) water-holding capacity.
D) water-transmitting capability, or hydraulic conductivity.
Answer: D
23) When subsurface ground material is completely saturated with water, we call it
A) the water table.
B) groundwater.
C) the saturated zone.
D) groundwater in the saturated zone.
Answer: D
24) The region above the zone of saturation is called the
A) water table.
B) zone of aeration.
C) aquifer zone.
D) none of the above.
Answer: B
25) The flow of groundwater depends on
A) porosity only.
B) permeability only.
C) porosity and permeability.
D) hydraulic gradient, and hydraulic conductivity.
Answer: D
26) The greater the hydraulic gradient the
A) slower the flow.
B) faster the flow.
C) greater the porosity.
D) less the permeability.
Answer: B
27) The necessary condition to produce an artesian system is
A) an unconfined aquifer that intersects the land surface.
B) a confined aquifer under sufficient pressure.
C) a confined aquifer that intersects the water table.
D) any of these
Answer: B
28) The flow of groundwater is dependent on
A) topography of the ground surface.
B) gravity only.
C) pressure only.
D) hydraulic conductivity and pressure.
Answer: D
29) The water table is found at the top of the
A) contact between an aquifer and an underlying, impermeable rock.
B) zone of aeration.
C) zone of saturation.
D) permeability zone.
Answer: C
30) When a perched water table intersects the surface on a hillside, the result is
A) an artesian well.
B) a spring.
C) a lake.
D) a cone of depression.
Answer: B
31) Water that does not inflitrate into the ground or evaporate becomes
A) groundwater.
B) runoff.
C) soil moisture.
D) hydrologic cycle.
Answer: B
32) What three factors affect porosity?
Answer: Porosity is the ratio of total volume of pore spaces in a soil or rock to total volume of
soil or rock. Porosity is affected by the size, shape, and packing of particles.
33) What three factors affect permeability?
Answer: Permeability is the ease with which water flows through a material. Permeability is
affected by pore spaces–specifically the number, size, and interconnection of pore spaces.
34) Why does quartz sandstone have a high porosity and a high permeability?
Answer: Quartz sandstone is predominantly composed of well-rounded, well-sorted sand
particles. Because most of the sand particles are of the same size, the spaces between the sand
particles are open and well connected. As such, water occupies the open spaces and easily moves
between the spaces.
35) Why does a clay rock body generally have a medium-to-high porosity but a poor hydraulic
conductivity?
Answer: Clay is composed of tightly packed, small, flattened grain particles. Although voids
between clay particles are small, clay is able to hold a lot of water. The movement of water,
however, is impeded by poorly connected, small pore spaces.
36) An aquifer is a reservoir of water beneath the ground surface. Describe five physical zones in
an aquifer. (Hint: Consider in-flow and out-flow.)
Answer: Unsaturated zone, saturated zone, water table, recharge area, and discharge area. The
unsaturated zone is where pore spaces are partially filled with water, below this area is the
saturated zone where all pore spaces are filled with water. The boundary between these two
zones is the water table. Water enters an aquifer in a recharge area. Water leaves an aquifer at a
discharge area–streams, artesian wells or springs, man-made wells, or as it enters a lake or ocean.
37) When a well is drilled into an aquifer, why does water flow out of the well spontaneously?
Answer: The well is an artesian system where water is brought up to the surface under its own
internal pressure. For an artesian system to form, the well must be drilled where the elevation of
the ground surface is lower than the elevation of the water table in the aquifer at the recharge
area.
22.3 The Work of Groundwater
1) If a water well is actively pumped, the water table will
A) be raised around the well.
B) stay at the same level as before pumping.
C) be depressed around the well.
D) be recharged.
Answer: C
2) Land subsidence is caused by
A) groundwater pumping.
B) clay layers that shrink.
C) gophers.
D) over-pumping of groundwater and the compaction of clay layers.
Answer: D
3) Underground rivers can exist in
A) limestone aquifers.
B) science fiction.
C) all aquifers.
D) any of the above.
Answer: A
4) Karst topography is dominated by
A) rivers and lakes.
B) sinkholes, caves, and caverns.
C) rugged hills and valleys.
D) glaciers.
Answer: B
5) Cave formation in limestone does NOT involve
A) mildly acidic groundwater.
B) dissolution of carbonate rocks.
C) land subsidence.
D) a dropping water table.
Answer: C
6) Over withdrawal of groundwater causes ground subsidence in areas
A) of karst topography.
B) underlain by unconsolidated sediments.
C) underlain by consolidated sediments.
D) all of these
Answer: B
7) The formations of rock hanging from the roofs of caves are called
A) moraines.
B) stalactites.
C) stalagmites.
D) dikes.
Answer: B
8) A rock that is readily attacked by chemical weathering is
A) limestone.
B) granite.
C) basalt.
D) gneiss.
Answer: A
9) Caves and caverns are formed in carbonate rock by
A) abrasive action of swift flowing groundwater.
B) reaction of carbonic acid released into the groundwater.
C) stalactites and stalagmites.
D) all of these
Answer: B
10) In general, sinkholes are found in areas
A) dominated by limestone.
B) in which groundwater is being pumped out of the ground too quickly.
C) where the dominant rock is shale.
D) with extensive irrigation systems.
Answer: A
11) Which of the following is not involved in cave formation in limestone?
A) Mildly acidic groundwater.
B) Dissolution of carbonate rocks.
C) Land subsidence.
D) A dropping water table.
Answer: C
12) Stalactites form from
A) a cave ceiling downward.
B) a cave floor upward.
C) calcium-rich water dripping down from the cave ceiling.
D) the accumulation of calcium-rich water dripping on the cave floor.
Answer: C
13) Land subsidence is generally not reversible because
A) compacted clay layers cannot be expanded.
B) once pumping is stopped, layers continue to compact.
C) compacted sandy aquifers cannot be expanded.
D) none of the above
Answer: A
14) As water is withdrawn from a well, the water table around the well
A) subsides.
B) drops, making a cone of depression around the well.
C) dries up.
D) rises.
Answer: B
15) How do caves and caverns form in limestone?
Answer: Rainwater falling through the air becomes slightly acidic from chemical reactions with
natural carbon dioxide in the air. When this slightly acidic rainwater comes in contact with
limestone, the acidic water partially dissolves the rock. For caves and caverns to form, time is
needed.
16) Rainwater becomes acidic as it falls through the air. How does this affect areas of Karst
topography?
Answer: Ground surface made up of carbonate rocks is prone to erosion. When slightly acidic
rainwater comes in contact with carbonate rocks, the carbonic acid partially dissolves the rock,
creating unusual erosional features–Karst. More acidic rainfall, more Karst topography.
17) What is a stalactite and how does it form?
Answer: A stalactite is an icicle-shaped carbonate rock formed in caves from dripping water rich
in calcium carbonate. As the calcium carbonate rich water drips downward, the water evaporates
and the calcium carbonate precipitates.
18) From the 1930s to the 1970s, extensive groundwater pumping in the San Joaquin Valley of
California caused the ground to subside by as much as 9 m. How does groundwater withdrawal
contribute to land subsidence?
Answer: Land subsidence can occur in areas underlain by thick sequences of poorly consolidated
sediments. As water is pumped from an aquifer with layers of easily compressed water-bearing
clays (low-permeability) interbedded with layers of sandy (high-permeability) rock, water slowly
leaks out of the clay layers. As the clays become dewatered, they compact, and the land subsides.
22.4 Surface Water and Drainage Systems
1) Common drainage networks include the
A) rectangular and divide drainage patterns.
B) radiating and undulating drainage patterns.
C) dentritic, radial, and trellis drainage patterns.
D) trellis, subsident, and perched drainage patterns.
Answer: C
2) Stream velocity is dependent on
A) the size and shape of the stream's channel.
B) the gradient and stream dimension.
C) gradient and friction.
D) gradient, channel geometry, and discharge.
Answer: D
3) Stream velocity is faster in a
A) flat bottomed, shallow stream channel.
B) rounded, relatively deep stream channel.
C) stream with a very steep gradient.
D) canyon.
Answer: C
4) The discharge of a stream is directly related to the
A) volume of water flowing past a given point in a channel in a given amount of time.
B) cross-sectional area of a channel and the average stream velocity.
C) average stream speed and frictional contact.
D) channel geometry and frictional contact.
Answer: B
5) In general, a stream with a high discharge tends to have
A) increased laminar flow.
B) increased turbulent flow.
C) a high velocity.
D) a narrow stream channel.
Answer: C
6) The speed of water in a stream is affected by
A) hydraulic gradient, recharge, and channel geometry.
B) gradient, discharge, and channel geometry.
C) high gradient, laminar flow, and erosion.
D) gradient, turbulence, and friction.
Answer: B
7) The volume of water that flows past a given point in a channel during a specified time is
called
A) load
B) gradient.
C) discharge.
D) runoff.
Answer: C
8) The cross-sectional area and shape of a stream is called
A) hydraulic gradient.
B) discharge.
C) channel dimension.
D) channel geometry.
Answer: D
9) Within a stream channel, the speed of stream flow is greatest
A) at the bottom of the stream bed.
B) in the middle of the channel at the water's surface.
C) at the channel sides.
D) mid-channel between the stream bed and the water's surface.
Answer: B
10) As streams move downslope, channel dimension generally
A) decreases with decreased discharge.
B) increases with decreased discharge.
C) narrows.
D) widens.
Answer: D
11) As a stream flows downslope, if discharge doubles but the cross-sectional area of the channel
stays the same, what happens to the average stream speed?
A) Average stream speed stays the same.
B) Average stream speed decreases.
C) Average stream speed increases.
D) Stream flow stops.
Answer: C
12) Riding down a river in an old canoe, if the discharge of the river does not increase and the
river gets very wide and deep, the speed of the river will
A) decrease.
B) increase.
C) stay the same.
D) become unpredictable.
Answer: A
13) Riding down a river in an old canoe, if the discharge of the river increases a little and the
width and the depth of the river stay the same, the speed of the river will
A) decrease.
B) increase.
C) stay the same.
D) become unpredictable.
Answer: B
14) What is stream channel geometry?
A) The change in elevation of a stream.
B) The shape of a stream channel as seen on a map.
C) The amount of turbulence and laminar flow in a stream.
D) The cross-sectional area and cross-sectional shape of a stream channel.
Answer: D
15) As a stream flows downslope, if stream discharge doubles and the cross-sectional area of the
channel also doubles, what happens to the average stream speed?
A) Average stream speed stays the same.
B) Average stream speed decreases.
C) Average stream speed increases.
D) Not enough information is given.
Answer: A
16) Water from streams in northern Utah flow to
A) the Atlantic Ocean.
B) the Gulf of Mexico.
C) the Pacific Ocean.
D) Colorado.
Answer: C
17) What three factors affect stream speed?
Answer: Gradient, the steeper the gradient the faster the flow; discharge, the greater the
discharge the faster the flow; and channel geometry, (a) water flows slower in large, wide
channels than in small narrow channels and (b) water flows faster in round deep channels than in
flat shallow channels.
18) When the discharge of a stream increases, what happens to stream speed?
Answer: An increase in discharge will always mean that a larger volume of water is being
transported by the stream. But an increase in discharge does not always mean that stream speed
will increase. Increases in discharge and speed do not always have a direct correlation because
changes in channel geometry and the cross-sectional area of the channel might also occur.
19) In a hypothetical stream flowing downslope, stream discharge doubles while the channel
remains the same size and shape. For this situation, what will happen to the stream's speed?
Answer: Stream speed will also double.
20) In a hypothetical stream flowing downslope, stream discharge doubles and the crosssectional area of the channel also doubles. For this situation, what will happen to the stream's
speed?
Answer: The cross-sectional area of the stream channel increased by the same percentage as the
discharge, so stream speed does not change.
22.5 The Work of Surface Water
1) Meandering streams are common in
A) V-shaped valleys.
B) natural levees.
C) flat floodplain areas.
D) areas of accumulation.
Answer: C
2) Flowing surface water alters the landscape in what ways?
A) Erosion.
B) Deposition of sediments.
C) Weathering.
D) It weathers and erodes sediments, and then it deposits sediment.
Answer: D
3) Which of the following is characteristic of mountain stream valleys?
A) They are curvy and slow moving.
B) They are V-shaped and have rapids.
C) They have deltas.
D) They are deep and wide.
Answer: B
4) On a floodplain, the sediment grains away from the main river channel are
A) coarse-grained sand and gravels.
B) fine-grained silts and clays.
C) well-sorted and well-rounded sand particles.
D) all of these
Answer: B
5) In a delta environment the first grains to settle are
A) light, fine-grained sediment.
B) heavier, coarse-grained sediment.
C) light, medium-grained sediment.
D) heavy and light mixed grains.
Answer: B
6) In a delta environment we find that fine-grained sediments settle
A) close to the mouth of the stream channel.
B) far away from the mouth of the stream channel.
C) both of these
D) none of these
Answer: B
7) Which of the following are NOT produced by streams?
A) Floodplains
B) Deltas
C) Moraines
D) Alluvial fans
Answer: C
8) The headwater flow of a mountain stream is generally characterized as
A) laminar.
B) turbulent.
C) meandering.
D) all of these
Answer: B
9) V-shaped valleys are
A) "old-age" valleys.
B) formed by glaciers.
C) of depositional origin.
D) common in mountainous regions.
Answer: D
10) Movement of water erodes stream channels. The main source of erosion comes from
A) physical abrasion.
B) chemical erosion.
C) laminar flow.
D) lithification.
Answer: A
11) On a floodplain, stream flow is generally
A) laminar.
B) turbulent.
C) meandering.
D) channeled.
Answer: C
12) In a meandering river, erosion is most notable on
A) the outer side of the meander.
B) the inner side of a meander.
C) both sides of a meander.
D) the bottom of the stream channel.
Answer: A
13) In a meandering stream, deposition of sediment occurs on
A) the outer side of the meander.
B) the inner side of a meander.
C) the bottom of the stream channel.
D) both sides of a meander.
Answer: B
14) Flowing water erodes stream channels by
A) chemical weathering.
B) hydraulic action and abrasion.
C) chemical weathering, hydraulic action, and abrasion.
D) channel erosion and abrasion.
Answer: C
15) As water flows around a river meander, erosion occurs
A) at a point bar.
B) on the outside of the meander.
C) on the inside of the meander.
D) on both the outside and inside of the meander.
Answer: B
16) Meanders
A) migrate downstream.
B) shorten the stream.
C) migrate upstream.
D) remain in one place.
Answer: A
17) The maximum volume of sediment a stream can carry is dependent on the stream's
A) laminar flow.
B) velocity.
C) discharge.
D) channel geometry.
Answer: C
18) The ability to carry large particle sizes is dependent on the stream's
A) laminar flow.
B) velocity.
C) discharge.
D) channel geometry.
Answer: B
19) The transport of large particle sizes is greatest
A) in turbulent streams.
B) when stream speed is very fast.
C) where the gradient exceeds the base level.
D) on the inside of a meander.
Answer: B
20) Streams transport great quantities of sediment. The most effective transport of sediment
occurs in
A) laminar flow.
B) turbulent flow.
C) particle flow.
D) groundwater flow.
Answer: B
21) As sediment travels in a downstream river, it changes by getting
A) coarser.
B) finer.
C) more poorly sorted.
D) more angular.
Answer: B
22) As a distributary channel in a delta becomes choked with sediment, the water in the channel
A) disappears.
B) will find a new route to its destination.
C) will puddle and eventually form a lake.
D) will move back upstream.
Answer: B
23) The Mississippi River has a huge delta. With each year and each episode of deposition, the
river
A) lengthens its course and the delta shrinks.
B) becomes choked and shortens as the delta grows.
C) course lengthens and the delta grows.
D) shortens as the delta moves upriver.
Answer: C
24) Deltas form as
A) periodic flooding clogs stream channels.
B) erosion clogs stream channels.
C) stream gradient decreases.
D) streams enter a standing body of water.
Answer: D
25) Point bars typically form
A) on the inside bend of a curved stream channel.
B) on the outside bend of a curved stream channel.
C) in the middle of a straight stream channel.
D) in the middle of a curved stream channel.
Answer: A
26) What is the lowest level to which water can erode land?
A) Sea level.
B) The bottom of the stream channel.
C) The level of the delta.
D) none of the above.
Answer: A
27) The maximum sediment load of a stream depends on
A) average stream speed.
B) channel geometry.
C) stream gradient.
D) stream discharge.
Answer: D
28) The work of surface water does all of the following EXCEPT
A) erosion.
B) deposition.
C) land subsidence.
D) delta formation.
Answer: C
29) Laminar flow produces
A) a stream carrying both large and small particles.
B) a stream carrying large particles.
C) clear streams.
D) less erosion.
Answer: D
30) The dumped sediment from a stream flowing into standing water is called a
A) delta.
B) floodplain.
C) drainage basin.
D) divide.
Answer: A
31) Fast moving, turbulent streams are highly erosive, they can
A) carry large sediment particles and a large volume of sediment.
B) meander and flood into deltas.
C) deposit only fine silts and muds.
D) form U-shaped valleys from gullies.
Answer: A
32) Rivers tend to flow
A) southward.
B) downhill due to gravity.
C) northward.
D) toward the Equator.
Answer: B
33) People settle on floodplains because
A) the chance of flooding is very rare.
B) floodplain soil is nutrient rich and good for agriculture.
C) of river access.
D) river access and rich soils.
Answer: D
34) How does energy relate to the way that streams meander?
Answer: At a stream's headwaters, a stream's energy is focused on downcutting. Downstream the
focus changes to a sinuous side-to-side motion. This reflects how the stream minimizes its
resistance to flow and dissipates its energy along the course. Meanders are the form a stream
takes as it adjusts its energy so that it can carry away all the sediment that it produces.
35) Where and how do deltas form?
Answer: A delta forms where a stream enters a body of standing water and loses its ability to
transport sediment. Large, coarse-grained sediments are the first to settle. Small, fine-grained
sediments (able to be carried out to the farther reaches of the delta) are the last to settle. Thus
sediment is deposited in order of decreasing weight, with heavy, coarse particles settling at and
near the shoreline and light, fine particles settling farther offshore.
36) In the formation of a river delta, why is it that coarser material is deposited first, followed by
medium and finer material farther out?
Answer: The deposition of sediment in a delta environment is due to a stream's inability to
transport sediment indefinitely. The settling of grain particles is directly related to inertia. Larger
grains have more mass and more inertia; thus larger grains are the first to settle out. Smaller
grains have less mass and less inertia and are the last to settle out.
37) In what three ways does flowing water erode a stream channel?
Answer: Chemical weathering, hydraulic action, and abrasion.
38) As a river overflows its channel, sediment is deposited along the channel banks. What type
of sediment is deposited first? What type is deposited last?
Answer: Large and heavy sediment particles are the first to be deposited since they are too heavy
to remain with the water flow. Small sediment particles, able to remain in the flow, are the last to
be deposited.
22.6 Glaciers and Glaciation
1) Glaciers flow downslope. A glacier moves fastest
A) when it begins to melt.
B) at its surface and in the center.
C) at its base and along its sides.
D) when ablation exceeds accumulation.
Answer: B
2) A glacier forms when
A) snow accumulates to form ice and the ice mass begins to flow under its own weight.
B) temperatures do not rise above freezing.
C) snow moves downslope under the influence of gravity.
D) meltwater at the base of a snowmass contributes to downslope flow.
Answer: A
3) The flow of a glacier begins
A) after it has reached a critical mass.
B) as pressure is exerted from behind.
C) when the accumulating snow begins to melt.
D) in the spring.
Answer: A
4) The annual amount of snow lost by a glacier is called
A) accumulation.
B) sublimation.
C) ablation.
D) sustation.
Answer: C
5) Glaciers lose mass by
A) crevassing.
B) calving.
C) melting and calving.
D) melting and crevassing.
Answer: C
6) The movement of a glacier is fastest
A) at the bottom.
B) at its surface.
C) in the middle.
D) along the sides.
Answer: B
7) Glaciers will retreat when the amount of accumulation
A) is less than the amount of ablation each year.
B) exceeds the amount of ablation each year.
C) is equal to the amount of ablation.
Answer: A
8) Which of the following is a necessary condition for an ice mass to be a glacier?
A) Accumulation must exceed ablation.
B) Basal sliding must occur.
C) The ice mass must move under its own weight.
D) Meltwater must be present.
Answer: C
9) Snow converts to glacial ice when subjected to
A) decreasing temperature.
B) pressure.
C) basal sliding.
D) plastic deformation.
Answer: B
10) A glacier grows and shrinks with the seasons. When a glacier is growing, we say it is
A) retreating.
B) advancing.
C) stationary.
D) crevassing.
Answer: B
11) Under what conditions does a glacier front advance? Under what conditions does a glacier
front retreat?
Answer: When accumulation exceeds ablation, the glacier advances—it grows.
When ablation exceeds accumulation, the glacier retreats—it shrinks.
12) What is "frictional drag" and how does it affect the external movement of a glacier?
Answer: Frictional drag is simply the slow down of movement due to the contact between two
opposing surfaces. Frictional drag slows down a glacier's external movement. The glacier
experiences this drag as it encounters the bedrock. So, movement is slowest at the base and at the
sides of the glacier.
13) What distinguishes a huge block of ice from a glacier?
Answer: Ice does not become a glacier until it moves under its own weight. This occurs when the
ice mass reaches a critical thickness of approximately 50 meters and the weight of the overlying
ice causes the ice at the base to deform plastically and flow downslope.
14) How do glaciers form and how do they move?
Answer: Glaciers form in climates cold enough that snow recrystallizes into ice. As snow
accumulates, the underlying ice thickens until it becomes so heavy that the forces of gravity
cause the glacier to move downslope. Glaciers move by a combination of basal sliding and
plastic flow.
22.7 The Work of Glaciation
1) The typical mountain valley that has been subjected to glaciation is shaped like
A) a semi-circle.
B) the letter "U."
C) one half of a square.
D) the letter "V."
Answer: B
2) Striations are long parallel scratches in
A) glaciers that show flow direction.
B) bedrock that show the direction of the glaciers flow.
C) bedrock that form next to roches moutonnées.
D) bedrock that show outwash flow direction.
Answer: B
3) Which of the following landscapes were not carved by glaciers?
A) The Grand Canyon
B) Yosemite National Park
C) The Swiss Alps
D) The Great Lakes of North America
Answer: A
4) Glacial deposits are characteristically
A) well sorted and well rounded.
B) composed of unsorted, angular rock fragments.
C) asymmetrical rock debris.
D) called outwash.
Answer: B
5) The depositional landform at the farthest advance of a glacier is called a
A) lateral moraine.
B) medial moraine.
C) terminal moraine.
D) stratified moraine.
Answer: C
6) A moraine is a
A) wind deposit.
B) river deposit.
C) glacial deposit.
D) glacial erosional landform.
Answer: C
7) Glacial debris is generally
A) well rounded and well sorted.
B) a mishmash of shapes and sizes.
C) unstriated.
D) angular and well sorted.
Answer: B
8) Common glacial landforms created of drift include moraines,
A) aretes, and drumlins.
B) drumlins, and roches moutonnees.
C) and drumlins.
D) roches moutonnees, and eskers.
Answer: C
9) Landforms created by glacial erosion include
A) hanging valleys, cirques, and drumlins.
B) cirques, drumlins, and roches moutonnees.
C) eskers, kettle lakes, and hanging valleys.
D) hanging valleys, cirques, and roches moutonnees.
Answer: D
10) The most powerful agent of erosion is
A) stream flow.
B) glacial action.
C) action from waves and ocean currents.
D) wind.
Answer: B
11) An unsorted mixture of rock material that is deposited directly by melting ice is called
A) drift.
B) outwash.
C) till.
D) snow.
Answer: C
12) Drumlins are made of
A) bedrock.
B) ice.
C) drift.
D) striations.
Answer: C
13) Blocks of ice buried in a glacial moraine often result in the formation of
A) drumlins.
B) roches moutonnees.
C) small glacial lakes–kettle lakes.
D) eskers.
Answer: C
14) Headward erosion of a group of cirques around a mountain may produce
A) glacial lakes.
B) an arete
C) a horn.
D) a hanging valley.
Answer: C
15) Glacial striations are caused by
A) rocks embedded in the ice.
B) glacial outwash.
C) terminal moraines.
D) melting ice.
Answer: A
16) A terminal moraine marks the
A) farthest a glacier can spread from side-to-side.
B) location where a glacier started to form.
C) farthest point of a glacier's advance.
D) location where outwash forms.
Answer: C
17) The two ways that glacial drift is deposited are
A) as outwash and till.
B) laminar and turbulent.
C) as crevasses and meltwater.
D) ablation and accumulation.
Answer: A
18) Erosion by alpine glaciers creates
A) V-shaped valleys.
B) U-shaped valleys.
C) drumlins.
D) moraines.
Answer: B
19) The direction of ice flow can be determined by
A) striations, roches moutonnées, and drumlins.
B) striations, roches moutonnées, and drumsticks.
C) moraines, drift, and till.
D) sled tracks, igloos, and drumsticks.
Answer: A
20) Which of the following is NOT a characteristic of continental glaciation?
A) Striations.
B) U-shaped valleys.
C) Drumlins.
D) Moraines.
Answer: B
21) Why are glacial striations so important?
Answer: Striations are parallel scratches created by glaciers scraping the underlying bedrock.
Aligned in the direction of ice flow, striations tell us the past movement of a glacier that has long
since receded. By mapping striations on land once covered by continental glaciers, geologist can
decipher the flow direction of the ice.
22) How do glaciers affect underlying rock?
Answer: Glaciers erode rock by scraping, plucking, and grinding underlying rock into sizes
ranging from boulders to fine dust. Alpine glaciers erode cirques, horns, and aretes at their heads;
U-shaped valleys and hanging valleys in their main courses; and fjords where glaciers end their
journey at the sea. Continental glaciers erode the land surface that they cover, smoothing and
rounding the entire underlying topography.
23) What is the difference between a roche moutonnee and a drumlin?
Answer: Both can reveal the direction of ice flow. They differ in how they formed. A roche
moutonnee is an erosional feature–eroded out of bedrock by continental glaciation, and a drumlin
is a depositional feature formed of glacial till.
22.8 The Work of Air
1) Sand dunes form
A) where air flows freely over sand.
B) from wind that is increasing in speed.
C) as wind moves sand from the back to the front of the dune.
D) as wind stops blowing.
Answer: C
2) The principal cause of erosion and transportation of sediment in a desert environment is
A) wind.
B) caravans.
C) ice.
D) water.
Answer: D
3) The most important agent of erosion is
A) water.
B) glaciation.
C) wind.
D) wave action.
Answer: A
4) Of the three agents of erosion–water, wind and ice–the one with the ability to move only the
smallest particles is
A) ice.
B) water.
C) turbulent water.
D) wind.
Answer: D
5) The main difference between sand dunes and ripple marks is
A) ripple marks are only caused by water.
B) ripple marks are larger than sand dunes.
C) sand dunes are larger than ripple marks.
D) ripple marks are stationary.
Answer: C
6) Sand dunes form as wind
A) disperses sand.
B) blows sand from the back to the front of the dune.
C) blows sand from the front to the back of the dune.
D) interrupts the normal sequence of deposition.
Answer: B
7) How are sand dunes formed?
Answer: Sand dunes form when airflow is blocked by an obstacle such as a rock or clump of
grass. As the wind sweeps over this obstacle, wind speed decreases and sand grains fall out of
the air and are deposited in the wind shadow. As more sand falls, a mound forms which further
blocks the flow of air. With more sand and more wind a dune forms.
8) Are sand dunes stationary or do they move and migrate?
Answer: Sand dunes migrate. The whole mound of sand moves downwind as sand grains on the
windward slope move up and over the crest of the dune to fall on the leeward slope. Sand
removed from the back of the dune is redeposited on the front of the dune. Over time, this
continuous process moves the entire dune.
Test Bank for Conceptual Physical Science
Paul Hewitt, John Suchocki, Leslie Hewitt
9780321752932, 9780134060491
