Q&A Hero

Q: The North American continent was covered by more ice than the South American continent at the height of the Ice Age.

Q: Land on the margins of continents that is presently under water would have been exposed to the atmosphere during glaciations because sea level would have been dozens of meters lower at that time.

Q: Sea level rises during a glaciation because glaciers are pushing down on the crust, which deforms the ocean basins.

Q: A kame is an ice-contact deposit.

Q: Outwash sediments are stratified by wind deposition.

Q: In order for a bimodal sediment to be called till, it must be directly deposited by glacial ice. If it is not, it is referred to as a diamicton.

Q: Because sea level does not act like base level with glaciers, a glacier can erode its bed below sea level.

Q: Most glaciers worldwide are currently in a state of retreat.

Q: Glaciers in arctic regions that are frozen to their beds move via internal deformation.

Q: When a glacier is in retreat, the ice can flow from the Zone of Ablation to the Zone of Accumulation.

Q: Glaciers form in areas where more snow falls in the winter than is lost in the summer.

Q: A glacier takes hundreds of thousands of years to form, but only a few thousand years to disappear.

Q: The only continental ice sheets left on Earth today are in Greenland and Antarctica.

Q: Glaciers are a single, solid piece of ice that flows from the Zone of Accumulation to the Zone of Saturation.

Q: When did the ice-free corridor open in North America, allowing a path for human migration from Asia? A) 12,500 years ago B) 9,000 years ago C) 100,000 years ago D) 7,500 years ago

Q: ________ refers to the change in the angle Earth's axis makes with the plane of our planet's orbit. A) Subduction B) Eccentricity C) Obliquity D) Precession

Q: The amount of solar radiation coming in at ________ helps to determine whether or not a planet is going into an Ice Age. A) 10 S B) 45 N C) 76 S D) 65 N

Q: How would plate tectonics explain the glaciation at the end of the Paleozoic Era, when no evidence of glacial ice can be found in high-latitude areas of North America and Eurasia? A) The climate was too warm for glacial ice on those continents. B) The glaciation was very small. C) The continents were joined to form Pangaea, which was located around the South Pole. D) There was an increased amount of solar radiation penetrating the atmosphere above those continents.

Q: ________ is the name for glacial deposits that have been lithified into a sedimentary rock. A) Tillite B) Loessite C) Sandstone D) Schist

Q: Which of the following is not part of the Milankovitch Cycle? A) Precession B) Obliquity C) Eccentricity D) Isostacy

Q: Which glacial erosion feature is likely to contain a waterfall today? A) Tarn B) Hanging valley C) Esker D) Horn

Q: Which continent had the greatest area covered by glaciers at the height of the Ice Age? A) South America B) Asia C) North America D) Europe

Q: What was the most recent episode of glaciation in North America? A) Nebraskan Episode B) Kansan Episode C) Illinois Episode Glaciation D) Wisconsin Episode Glaciation

Q: What is a pluvial lake? A) A lake that forms on the margins of glaciers from glacial meltwater B) A lake that fills in an arid/semiarid region due to increased precipitation in a cooler, wetter climate C) A lake forming from a stagnant piece of melting glacial ice caught between two recessional moraines D) A subterranean lake forming in a sinkhole

Q: How does isostatic rebound affect a glacial landscape after the glacier is removed? A) A depressed crust rises after glacial retreat. B) Advancing glaciers erode bedrock, which allows rock to spring up. C) Meltwater streams deposit sediment, severely depressing the landscape. D) Weight of water forces the crust downward.

Q: ________ are former river valleys that were oriented parallel to the direction of ice flow and were scoured deeper by advancing glacial ice. A) Hanging valleys B) Paternosters C) Finger lakes D) Kettle lakes

Q: Which state would you not expect to contain drumlins, eskers, and kettle lakes? A) Minnesota B) New York C) Kentucky D) Michigan

Q: Why would construction businesses find eskers to be economically important? A) They provide flat areas for transportation routes. B) They provide nutrient-rich farmland. C) They provide easy access to water sources. D) They provide easily accessible sand and gravel deposits.

Q: Which of the following scenarios can lead to the formation of a kame? A) Sediment accumulates in a hole in the ice. B) Sediment is carried on top of the glacier. C) Sediment collects in subglacial stream channels. D) Sediment covers a stagnant block of ice.

Q: Which of the following descriptions does not specifically apply to sediments carried away from the glacier by meltwater streams? A) Deposited in stratified layers B) Composed of clay-rich materials C) Often well sorted D) Composed of sands and gravels

Q: There have been several instances in the last 150 years when valuable materials such as diamonds have been found contained in glacial debris. If one wanted to try to trace such valuable materials back to their source, which moraine would be most useful for tracing valuable gold deposits back to their bedrock source area? A) Recessional moraine B) Terminal moraine C) Lateral moraine D) Esker

Q: What bodies of water are formed when a stagnant block of glacial ice near the terminus becomes partly or completely buried in glacial sediments, eventually melting to create a lake? A) Tarns B) Paternosters C) Braided streams D) Kettle lakes

Q: Deposits of stratified sands and gravels transported from the glacial margin by meltwater are called a(n) ________ when adjacent to an ice sheet and a(n) ________ when adjacent to an alpine glacier. A) lateral moraine; kame B) drumlin; outwash plain C) outwash plain; valley train D) terminus; esker

Q: Which of the following best explains the formation of a medial moraine on a glacier? A) A gravel pile that marks periods of glacial readvancement B) A ridge of debris carried down the center of glacial ice C) Sands and gravels that fill a subglacial stream channel D) A ridge of debris carried along the sides of an advancing glacier

Q: Lateral and medial moraines are found in connection with ________ glaciation. A) alpine B) ice shelf C) continental D) ice cap

Q: Read the following excerpt from The Works of John Playfair (1822). What glacial landform is being described? "...For the moving of large masses of rock, the most powerful engines without doubt that nature employs are the glaciers....[Rock] fragments they gradually transport to their utmost boundaries, where a formidable wall ascertains the magnitude, and attests the force, of the great engine by which it was erected." A) Arte B) Drumlin C) Horn D) Moraine

Q: Which moraine marks the furthest extent of glacial ice? A) Lateral moraine B) Medial moraine C) Recessional moraine D) Terminal moraine

Q: ________ is unsorted, unstratified, bimodal sediment directly deposited by the glacial ice. A) Loess B) Outwash C) Till D) Diamicton

Q: ________ is fine silt generated by glaciers that can be carried for long distances by the wind. A) Loess B) Outwash C) Till D) Diamicton

Q: ________ are stratified sands and gravels carried away from the glacial terminus by meltwater. A) Loess B) Outwash C) Till D) Diamicton

Q: Which part of a glacier is responsible for abrasion and plucking? A) Basal sliding zone B) Glacial interior C) Terminus D) Brittle surface zone

Q: A(n) ________ is a sharp mountain peak created by erosion from several cirque glaciers. A) arte B) cirque C) glacial trough D) horn

Q: A(n) ________ is a sharp, knife-edged ridge that forms between two valley glaciers. A) horn B) arte C) col D) moraine

Q: A ________ is a small, circular lake that occupies a cirque basin. A) drift B) marsh C) tarn D) fenster

Q: What shape do glacial troughs generally display? A) V B) W C) Y D) U

Q: ________ is an erosional method where meltwater penetrates fractures in subglacial bedrock and freezes. A) Plucking B) Comminuting C) Spalling D) Abrasion

Q: Artes, horns, and hanging valleys are evidence of ________ glaciation. A) alpine B) ice shelf C) continental D) ice cap

Q: What kind of geothermal feature is visible in this image? A) Hot spring B) Artesian well C) Geyser D) Subsidence

Q: What feature is highlighted with an arrow in this image? A) Sinkhole B) Perched water table C) Cone of depression D) Ground subsidence

Q: Assume that the irrigation well in the middle of this image was installed by a seed corn company and not by the farmers who own the local wells on either side. If irrigation were stopped immediately, would this localized lowering recover immediately? Why or why not? A) Yes. Water from other parts of the aquifer could replace what was lost. B) No. The average aquifer has a groundwater flow rate of 4 cm/day. C) Yes. The reduced pressure in the aquifer would allow the groundwater to flow faster. D) No. Now that irrigation has stopped, there is no suction necessary to draw the water.

Q: What localized lowering of the water table is present in this figure? A) Ground subsidence B) Cone of depression C) Sinkhole D) Hot spring

Q: Assume that chemical pollutants have been buried at Point Y. The heavy dashed arrow shows the path of infiltration the pollutants followed. Which other bodies of water will be contaminated by these pollutants? A) Both lakes B) The major river and the left-hand lake C) All bodies of water will be contaminated. D) The contamination is flowing below the aquitards, so none will be contaminated.

Q: Assume that chemical pollutants have been illegally dumped in the major river on the left side of this image. Will those pollutants infiltrate and contaminate any other bodies of water? If so, which ones? A) Stream B) Left-hand lake C) Right-hand lake D) None. The major river is a discharge point

Q: Examine the groundwater flow patterns around Point X. Into which bodies of water (if any) will water that infiltrates at Point X eventually discharge? A) Stream B) Left-hand lake C) Right-hand lake D) Major river

Q: This image shows the gradient of the water table between Well A and Well B. Please note that the label for each well also displays the elevation of the water table in that well. Using the information present in the figure, calculate the hydraulic gradient of this cross section. A) 8 m/km B) 11.7 m/km C) 21.9 m/km D) 32 m/km

Q: Match the correct label to the type of gaining/losing stream. A) Losing stream (connected) B) Gaining stream C) Losing stream (disconnected) 1. 2. 3.

Q: The points on this figure mark the locations of groundwater observation wells. The numbers refer to the elevation of the water table above sea level. Using this information, determine the direction of groundwater flow in this region. Assume that the top of the figure is north. A) Northeast B) West C) South D) Southwest

Q: Using the image above, label the following. A) Capillary Fringe B) Zone of Saturation C) Water Table D) Unsaturated Zone 1. A 2. B 3. C 4. D

Q: Explain the process of cave formation.

Q: Major coastal cities such as Charleston, South Carolina, have to find a delicate balance between supplying enough water for a healthy, growing city and preventing contamination of their groundwater supplies with saltwater due to overpumping. What steps could be taken to counteract the effects of saltwater contamination without abandoning the well? Explain.

Q: Compare and contrast a geyser and a hot spring.

Q: Some bottled water companies advertise that their product is clean and pure because it comes from an artesian well. Discuss the validity of this statement.

Q: What is the difference between a flowing artesian well and a nonflowing artesian well?

Q: Explain how artesian wells are created. Your explanation should include a discussion of how they get recharged.

Q: A severe drought in 2012 devastated much of the United States, causing crop failure, lower stream levels, and the drying and cracking of the ground. Obviously, a great deal of water was needed to end this drought. At the end of August of that year, Hurricane Isaac made landfall along the Gulf Coast of Louisiana and Mississippi and proceeded to move up the Mississippi River and across central and northern Illinois by August 31 and September 1, precipitating large volumes of rain as it moved. How did the transit of Hurricane Isaac affect the drought (Did it end the drought?)? How would groundwater levels change? Explain your answers.

Q: Explain how groundwater can sustain streams even during a long drought.

Q: Match the water feature with the correct definition. A) Intermittent hot springs that periodically eject water into the air with great force B) Water in a basin that is 6-9C warmer than the mean annual temperature of the location C) Water under pressure in a confined aquifer that will rise above the level of the aquifer D) A natural outflow of water where the water table intersects the surface 1. Geyser 2. Spring 3. Hot spring 4. Artesian well

Q: Match the word with the correct definition. A) Rock or regolith that can store and transmit water but is contained between two impermeable layers B) Rock or regolith that can store and transmit water and receives its recharge directly from the atmosphere C) Impermeable layer that prevents flow 1. Aquitard 2. Confined aquifer 3. Unconfined aquifer

Q: What physical features are evidence of a karst landscape?

Q: What is different about mineral deposits at Mammoth Hot Springs compared to other geothermal features in Yellowstone National Park? From which rock were these mineral deposits derived?

Q: Igneous and metamorphic rocks do not form with voids or pore spaces where groundwater can reside. However, these rocks can often both store and transport groundwater. What voids would make up the secondary porosity of igneous and metamorphic rocks?

Q: Which has a higher porosity: sand or sandstone? Why?

Q: Undulations of the water table mimic those of the ground surface. What would happen to those undulations in the water table if all rain were to cease?

Q: How do scientists map the water table?

Q: Caves can only form in limestone.

Q: Most caverns are created at or near the water table.

Q: Stalactites grip tightly to the floor of a cave whereas stalagmites hang from the ceiling.

Q: If a groundwater well pumps enough water to draw down the water table, the drawdown will increase the slope of the water table, which will increase the velocity of groundwater.

Q: In semiarid to arid regions, groundwater is considered a nonrenewable resource because it isn't replaced at the same rate as it is withdrawn.

Q: Freshwater is less dense than saltwater.