Name: Date:

Geology 12: Surface Processes and the Hydrosphere Review

Part A: Multiple Choice

Stream Erosion

1) Which one of the following does not apply to stream turbulence and average velocity?A) channel shape; bed roughnessB) laminar flow; dissolved loadC) discharge; stream gradientD) stream gradient; channel roughnessAnswer: B

2) ________ describes the amount of water flowing past a certain point at any given time.A) CapacityB) DischargeC) CompetenceD) Hydro-load factorAnswer: B

3) ________ describes the maximum solid particulate sediment load transported by a stream.A) CapacityB) DischargeC) CompetenceD) Hydro-load factorAnswer: A

4) Which of the following features characterize wide streams and valleys?A) natural levees; broad floodplainsB) rapids; channel bed potholesC) waterfalls; entrenched meandersD) V-shaped valley cross-sectionsAnswer: A

5) Which one of the following best fits with floodplain widening?A) youthful stream; downcutting and waterfall retreatB) old age stream; rapid erosion of a deltaC) mature stream; lateral cutting and point bar depositionD) stream rejuvenation; downcutting and meanderingAnswer: C

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6) Where is erosion concentrated along a meandering stream?A) on the straight channel segments that connect the meander loopsB) on the outer parts of the meander loops or bendsC) at the unconsolidated point barsD) on the inner banks of the meander loopsAnswer: B

7) A ________ stream consists of a complex network of converging and diverging channels that weave around channel bars.A) Straight channelB) Meandering streamC) Braided streamD) Bedrock channelAnswer: C

8) Which of the following statements best characterizes alluvial fans?A) They develop where a high-gradient stream leaves a narrow mountain valley and deposits on a flat area.B) They develop where a low-gradient stream leaves a wide valley and deposits in a canyon.C) They develop where a low-gradient tributary meets the main stream.D) They develop where a high-gradient tributary splits when it enters a flat area.Answer: A

9) The most likely region for turbulent flow due to an unconsolidated stream bed is:A) 1 and 3B) 3 and 4C) 4 and 5D) 5 and 6Answer: A: Unconsolidated sediments like cobbles, etc can be eroded. This creates a varied stream bed that allows turbulent water flor (water moves in erratic, swirling pattern).

10) In a typical stream, the suspended sediment load ________.A) decreases greatly during floodsB) usually includes fine sand, silt, and clayC) saltates along the bottomD) weighs less than its total dissolved constituentsAnswer: B

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Groundwater Erosion

1) Where does the majority of groundwater originate?A) by infiltration from precipitation that falls on the landB) by primordial outgassing from magmatic intrusionsC) it was deposited along with the sediments that contain itD) released from minerals undergoing diagenetic and metamorphic dehydration reactionsAnswer: A

2) A water table is the ________.A) boundary between the zone of saturation above and partly saturated zone belowB) bottom boundary surface of the zone of saturation above an aquitardC) boundary between the zone of aeration above and zone of saturation belowD) boundary between the zones of aeration and superpositionAnswer: C

3) Which statement concerning the water table is false?A) In humid regions, it is generally higher than lake or stream level.B) Its elevation is constant and does not fluctuate seasonally.C) Its shape is a subdued replica of the overlying surface topography.D) Wetlands (swamps) occur where the water table is at the surface.Answer: B

4) ________ is the volume of voids or open space in a rock or unconsolidated material.A) PermeabilityB) PorosityC) Saturation indexD) CapillarityAnswer: B

5) ________ is a measure of the connectedness of pore spaces, which controls the ease (or difficulty) of groundwater transmission through a porous material.A) PortabilityB) PotabilityC) PermeosityD) PermeabilityAnswer: D

6) Of the choices listed below, which would make the best aquitard?A) clayB) basaltC) graniteD) sandAnswer: A

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7) An aquifer is ________.A) a saturated, porous, and permeable layer or stratum that has high water flowB) a layer or stratum in which groundwater flows downward to the water tableC) an unsaturated bed or stratum below a springD) the best place to dispose of soluble toxic wasteAnswer: A

8) The fastest groundwater flows would be expected for an aquifer with ________.A) high porosity and many small poresB) high gradients (hydraulic head) and high permeabilityC) low gradients and low permeability with a few very large poresD) high specific retention and low permeabilityAnswer: B

9) Which of the following describes the configuration of an unconfined water table around a pumping well?A) a bad impressionB) cone of depressionC) depression withdrawalD) inverted cone headAnswer: B

10) An artesian well is one in which ________. A) the water is warm, fairly saline, and recharged by an affluent stream B) pressurized groundwater rises from a deep, unsaturated aquifer C) water rises above the top of the aquifer without any pumping D) the well is horizontal and the water table is perched Answer: C

11) Excessive groundwater withdrawals can cause ________.A) uplift through expansion of the dewatered aquiferB) the water table to decline in elevation and land to subsideC) porosity in the aquifer to increase as the water is removedD) the cone of depression to invertAnswer: B

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Glacier Erosion

1) At what depth or thickness of ice does glacial ice make the transition from brittle fracture to plastic flow?A) 1 metreB) 5 metresC) 10 metresD) 50 metresAnswer: D

2) Glaciers can deform internally to behave like a plastic material and flow because ________.A) the bonds between successive layers of ice are weaker than those within a single layer, allowing the glacier to slip like a stack of cardsB) there are layers of pure liquid water between the annual layers of iceC) there are layers of air between the layers of iceD) there are round rock particles within the ice that act like little ball bearingsAnswer: A

3) ________ is one of the three ways a glacier can move over its bed.A) Basal slipB) Crevassal slipC) Frost heavingD) Morainal slidingAnswer: A

4) The bottom or downward tip of a crevasse marks the ________.A) boundary between parts of the glacier moving by basal sliding and crevassal slipB) boundary between the basal sliding and external flowage zonesC) bottom of the basal sliding zoneD) top of the internal deformation and flowage zone, and the base of the brittle zone of fractureAnswer: D

5) Which one of the following applies to a valley glacier that lengthens (extends its terminus downslope) over a span of many years?A) wastage exceeds accumulationB) accumulation exceeds wastageC) accumulation and wastage are about equal; the older ice moves fartherD) the glacier experiences no accumulation or wastageAnswer: B

6) Which phrase best describes what would likely happen during the retreat of a valley glacier?A) A line of stakes across the glacier would be gradually lowered to the valley floor directly beneath where they were originally placed.B) A line of stakes across the glacier would continue to move down valley as the terminus of the glacier slowly retreated.C) A line of stakes would retreat slowly up valley as the ice withdraws to its source region.D) Who cares? The beer would get too warm!

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Answer: B

7) As a glacier advances over a fractured bedrock surface, it loosens, lifts, and incorporates blocks of rock in a process called ________.A) frost wedgingB) hydraulic liftingC) pluckingD) striationAnswer: C

8) What type of moraine is formed by the merging of two lateral moraines at a junction of two valley glaciers?A) medialB) recessionalC) groundD) collateralAnswer: A

9) Drumlin fields contain ________.A) smooth, tapering, asymmetric ridges of till usually formed and shaped beneath a continental ice sheetB) bowl-shaped depressions eroded largely by frost action and glacial pluckingC) mounds of outwash deposited by meltwater streams at the snout of a glacierD) smooth, striated, bedrock ridges shaped and polished by a glacier's erosive actionAnswer: A

10) A(n) ________ represents a former meltwater channel or tunnel on, in, or beneath glacial ice, that became filled with sand and gravel.A) drumlinB) esker C) kettleD) valley trainAnswer: B

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Part B: Short Answer

Stream Erosion

1) Briefly compare those stream characteristics that decrease in a downstream direction with those that increase downstream. Also, indicate whether these changing stream characteristics tend to favor erosion or deposition of sediments.Answer: Gradient, turbulence, bed roughness generally decrease while discharge, velocity, channel width and depth tend to increase. Both erosion and deposition will occur downstream depending on bedrock hardness, channel smoothness, and temporary base levels encountered. Deposition will occur at point bars and in channels as the stream migrates back and forth across its valley, and erosion will concentrate on cutbanks and bedrock outcrops encountered along its journey.

2) Examine the diagram below. Explain how the river depicted will evolve over time and what stream features will be produced as a consequence.

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Groundwater Erosion

1. A hydro-geologist has drilled three exploratory wells (X, Y, Z) in search of a suitable location for a new garbage landfill site. In order to investigate the rocks in the test wells, the hydro-geologist measured the porosity by noting how much water was contained in each of the rocks when saturated. The hydro-geologist also attached a pump to the top of each well and determined the rate at which water could be drawn to the surface. The results of these tests are given above.

a) Choose the well which is the best location for a garbage landfill site and explain why you have made this decision. (2 Marks)

b) In preparing the landfill site, what other precautions could be taken to ensure that drainage liquids do not contaminate the groundwater? (1 Mark)

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c) During the pump tests, the level of the water table in well Y was lowered by 10 metres. How would this affect the water table in each of the other two wells? (1 Mark)

Glacier Erosion

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