Geology Ch 18 Review Sheet

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A glacier is a ________ that forms over hundreds or thousands of years. 1) _____ A) thick ice mass B) ice floe C) snow field D) iceberg 2) Although we know that the total amount of ice is shrinking, at the present time what percentage of the Earth's land surface is currently covered by glacial ice? 2) _____ A) 2% B) 33% C) 15% D) 10% 3) Which of the following locations does not currently have glaciers? 3) _____ A) Scotland B) Alaska C) Antarctica D) Norway 4) When was the Last Glacial Maximum? 4) _____ A) 100,000 years ago B) 18,000 years ago C) 32,000 years ago D) 10,000 years ago 5) The Hubbard Glacier in North America is an example of which kind of glacier? 5) _____ A) Cirque B) Valley C) Piedmont D) Ice Sheet 6) Which of the following ice bodies is an example of alpine glaciation? 6) _____ A) Iceberg B) Ice Cap C) Valley D) Ice Sheet 7) Glaciers form because of the accumulation of large amounts of ice and snow. Which of the following provides the most water needed to create glaciers? 7) _____ A) Geysers B) Streams C) Oceans D) Groundwater 8) The Laurentide Ice Sheet is an example of ________ glaciation. 8) _____ A) valley B) alpine C) continental D) ice cap 9) ________ is an elevation point above which snow remains throughout the year.9) _____ A) Snowline B) Firn C) Surge D) Grounding line 10) Which crevasse will form perpendicular to the terminus as a glacier moves over a change in slope? 10) _____ A) Transverse B) Longitudinal C) Moulin D) Bergschrund 11) Why are the ice shelves off Antarctica breaking off? 11) _____ A) Global warming B) Biological activity C) Shifts in Earth's axis D) Wave activity 12) Arêtes, horns, and hanging valleys are evidence of ________ glaciation. 12) _____ A) continental B) ice cap C) alpine D) ice shelf 13) ________ is an erosional method where meltwater penetrates fractures in subglacial bedrock and freezes. 13) _____ A) Comminuting B) Abrasion C) Spalling D) Plucking 14) What shape do glacial troughs generally display? 14) _____ A) W B) U C) V D) Y 15) A ________ is a small, circular lake that occupies a cirque basin. 15) _____ A) drift B) fenster C) marsh D) tarn 16) A(n) ________ is a sharp, knife-edged ridge that forms between two valley glaciers. 16) _____ A) arêteB) col C) horn D) moraine 17) Which part of a glacier is responsible for abrasion and plucking? 17) _____ A) Glacial interior B) Brittle surface zone C) Basal sliding zone D) Terminus 18) How is "rock flour" formed? 18) _____ A) Rock flour is subsurface sediment that rises due to plastic flow B) A glacier pulverizes rocks C) Rock flour is small pieces of ice that form on the edge of the zone of accumulation D) Meltwater carries minerals that precipitate 19) Long narrow grooves gouged into the rock by glacial erosion are called ________. 19) _____ A) pater nostersB) striations C) ablations D) streaks 20) ________ are stratified sands and gravels carried away from the glacial terminus by meltwater. 20) _____ A) Loess B) Outwash C) Till D) Diamicton 21) ________ is fine silt generated by glaciers that can be carried for long distances by the wind. 21) _____ A) Loess B) Outwash C) Till D) Diamicton 22) ________ is unsorted, unstratified, bimodal sediment directly deposited by the glacial ice. 22) _____ A) Loess B) Outwash C) Till D) Diamicton 23) Which moraine marks the furthest extent of glacial ice? 23) _____ A) Recessional moraine B) Medial moraine C) Lateral moraine D) Terminal moraine 24) 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." 24) _____ A) Horn B) Drumlin C) Moraine D) Arête 25) Lateral and medial moraines are found in connection with ________ glaciation. 25) _____ A) ice shelf B) ice cap C) alpine D) continental 26) Which of the following best explains the formation of a medial moraine on a glacier? 26) _____ A) Sands and gravels that fill a subglacial stream channel B) A ridge of debris carried down the center of glacial ice C) A ridge of debris carried along the sides of an advancing glacier D) A gravel pile that marks periods of glacial readvancement 27) 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. 27) _____ A) lateral moraine; kame B) outwash plain; valley train C) terminus; esker D) drumlin; outwash plain 28) 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? 28) _____ A) Paternosters B) Tarns C) Kettle lakes D) Braided streams 29) Which of the following descriptions does not specifically apply to sediments carried away from the glacier by meltwater streams? 29) _____ A) Composed of sands and gravels B) Deposited in stratified layers C) Composed of clay-rich materials D) Often well sorted 30) Which of the following scenarios can lead to the formation of a kame? 30) _____ A) Sediment is carried on top of the glacier. B) Sediment collects in subglacial stream channels. C) Sediment accumulates in a hole in the ice. D) Sediment covers a stagnant block of ice. 31) Why would construction businesses find eskers to be economically important? 31) _____ A) They provide flat areas for transportation routes. B) They provide easily accessible sand and gravel deposits. C) They provide nutrient-rich farmland. D) They provide easy access to water sources. 32) Which state would you not expect to contain drumlins, eskers, and kettle lakes? 32) _____ A) Tennessee B) Minnesota C) Michigan D) New York 33) As glacial ice flows around sharp curves, its great erosional force removes the ________ of land that extend into the valley. 33) _____ A) eskers B) spurs C) kames D) moraines 34) What name do we give to large boulders that have been carried long distances by glacial ice? 34) _____ A) Rouche moutonees B) Drumlins C) Outwashes D) Erratics 35) ________ are former river valleys that were oriented parallel to the direction of ice flow and were scoured deeper by advancing glacial ice. 35) _____ A) Hanging valleys B) Paternosters C) Kettle lakes D) Finger lakes 36) How does isostatic rebound affect a glacial landscape after the glacier is removed? 36) _____ A) A depressed crust rises after glacial retreat. B) Weight of water forces the crust downward. C) Advancing glaciers erode bedrock, which allows rock to spring up. D) Meltwater streams deposit sediment, severely depressing the landscape. 37) What is a pluvial lake? 37) _____ A) A subterranean lake forming in a sinkhole B) A lake that forms on the margins of glaciers from glacial meltwater C) A lake that fills in an arid/semiarid region due to increased precipitation in a cooler, wetter climate D) A lake forming from a stagnant piece of melting glacial ice caught between two recessional moraines 38) One of the most famous drumlins is ________, a scene of a Revolutionary War battle. 38) _____ A) Bunker Hill B) Gettysburg C) Camden D) Antietam 39) What was the most recent episode of glaciation in North America? 39) _____ A) Wisconsin Episode Glaciation B) Nebraskan Episode C) Illinois Episode Glaciation D) Kansan Episode 40) Which continent had the greatest area covered by glaciers at the height of the Ice Age? 40) _____ A) Asia B) South America C) North America D) Europe 41) The tilt of Earth's rotational axis is ________. 41) _____ A) unpredictable B) always pointing toward Vega C) always fixed at 22.75 degrees from the vertical D) varying between 22 and 24.5 degrees from the vertical over the course of 41,000 years 42) Which glacial erosion feature is likely to contain a waterfall today? 42) _____ A) TarnB) Horn C) Esker D) Hanging valley 43) Which of the following is not part of the Milankovitch Cycle? 43) _____ A) Obliquity B) Isostacy C) Eccentricity D) Precession 44) 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? 44) _____ A) The climate was too warm for glacial ice on those continents. B) There was an increased amount of solar radiation penetrating the atmosphere above those continents. C) The glaciation was very small. D) The continents were joined to form Pangaea, which was located around the South Pole. 45) ________ refers to the change in the angle Earth's axis makes with the plane of our planet's orbit. 45) _____ A) Obliquity B) Eccentricity C) Precession D) Subduction 46) When did the ice-free corridor open in North America, allowing a path for human migration from Asia? 46) _____ A) 7,500 years ago B) 9,000 years ago C) 100,000 years ago D) 12,500 years ago 47) The end of the last glacial cycle has led to unloading of the land surface in Canada and Scandinavia, producing glacial ________. 47) _____ A) plucking B) rebound C) saltation D) accumulation