EAR 105 Chapter 12 Questions PDF

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chapter 12 quiz review with answers...

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1 EAR 105 Chapter 12 1. ___ are the product of past glaciations. The great lakes 2. The upper part of a glacier, the part with perennial snow and ice, is called the __. Zone of accumulation 3. Glaciers can be considered as _______ of fresh water for future use. Deposits 4. Above the rigid zone, glacial ice movement is due to __. Passive riding of the ice on the glacier 5. If all ice sheets were to melt, sea level would _____. Ride by over 60 meters 6. A worldwide decrease of at least _____°C in temperature would bring about a new glacial age. 5 7. ____ are landscape features that indicate a mountainous area has been glaciated. Cirques, horns, and arêtes 8. The longest ice core drilled was obtained at ____, Antarctica, in the 1990s. Vostok 9. Under the influence of gravity a glacier moves down valley and eventually __. Ablates 10. The central portion of a valley glacier moves _____ the sides. Faster than 11. When an ice block that was buried in sediment finally melts a depression called a ___ forms. Kettle 12. A(n) _____ -shaped valley (in cross section) is characteristic of glacial erosion. U 13. Sharp ridges called ___ separate adjacent glacially carved valleys. Aretes 14. A large trunk glacier carves a deeper valley than smaller tributaries. After the glacier disappears the tributary valley remains as _____ high above the main valley. A hanging valley

15. A(n) _______ is a mass of ice that is not restricted to a valley but covers large areas of land. Ice sheet

2 EAR 105 Chapter 12 16. Bodies of till shaped into streamlined hills are called ___. Drumlins 17. A(n) ______ is a steep-sided half-bowl shaped recess carved at the head of a mountain glacial valley. Cirque 18. A(n) _____ is a coastal inlet that is formed by a drowned glacial carved valley. Fiord 19. A(n) ____ is a long sinuous ridge of water-deposited cross-bedded and well-sorted sediment deposited by a stream that flowed within or under a glacier. Esker 20. What caused the glacial ages? All of the above have contributed to the glacial ages; the changes in the atmosphere, changes in the positions of the continents, changes in circulation of sea water 21. The _____ is the end of a glacier.

Terminus 22. Open fissures called ___ develop in the brittle surface ice of glaciers. Crevasses 23. A glacier will flow faster where it is steeper and _____. Thicker

24. If a moving glacier reaches a body of water ______ float free. Icebergs 25. The down-valley part of a glacier is the ____, where melting, evaporation, and calving take place. Zone of ablation 26. ___ moraines are elongate low mounds of till that form along the sides of valley glaciers. Lateral 27. A(n) ___________ is an ice-transported boulder that was not derived from the underlying bedrock. Erratic 28. Two layers of sediment resulting from one year's deposition in a glacial lake are called ___.

Varves 29. The sediment deposited by debris-laden melt water is called _______.

3 EAR 105 Chapter 12 Outwash 30. A(n) _____ is the sharp peak that remains after cirques have cut back into a mountain on several sides. Horn 31. The boundary between the zone of accumulation and the zone of ablation is an irregular line called the _____. Equilibrium line 32. Where tributary glaciers come together the adjacent lateral moraines join to form a ______ moraine. Medical 33. A(n) ___ is a lake occupying a bedrock depression excavated by a glacier. Tarn 34. The theory of _____ states that at times in the past, colder climates prevailed during which much more of the land surface was glaciated than at present time. glacial ages 35. The grinding of rock against rock by a glacier produces a very fine sediment called ____. Rock flour 36. ______ gives us more evidence of the beginning and ending times of glacial episodes than the direct study of glacial deposits. Deep ocean sediment 37. ______ first suggested that glacial/interglacial episodes are related to variation in solar radiation cycles. M. Milankovitch 38. If the terminus of a glacier remains stationary for a few years a distinct _______ may form. Recessional moraine 39. Once a glacier is gone the land begins to uplift slowly to its pre-glacial height, a process called ____. Crustal rebound 40. As ice retreats by melting back, the rock debris carried by the glacier is deposited to form a relatively thin layer of till called a(n) ___________. Ground moraine...