1. Glaciers and Glacial Mechanics

2. Glacier Origins and Types

3. Glacier Origins and Types
Glacier (def): a body of moving ice that has been formed on
land by compaction and recrystallization of snow.

4. Glacier Origins and Types
Glacier (def): a body of moving ice that has been formed on
land by compaction and recrystallization of snow.
B. Critical Requirements

5. B. Critical Requirements
Must be formed from the accumulation and ‘metamorphism’
of snow.

6. B. Critical Requirements
Must be formed from the accumulation and ‘metamorphism’
of snow.
Ice must be moving under its own weight.

7. B. Critical Requirements
Must be formed from the accumulation and ‘metamorphism’
of snow.
Ice must be moving under its own weight.
Must originate on land

8. B. Critical Requirements
Must be formed from the accumulation and ‘metamorphism’
of snow.
Ice must be moving under its own weight.
Must originate on land
Persist from year-to-year

9. Glacier Origins and Types
C. The recrystallization of snow

13. II. The Movement of Glaciers

14. II. The Movement of Glaciers
Basal Sliding

16. II. The Movement of Glaciers
Basal Sliding
Plastic Flow/Internal Shearing
Internal Shearing

17. II. The Movement of Glaciers
Basal Sliding
Plastic Flow/Internal Shearing

19. II. The Movement of Glaciers
C. Crevassing (Zone of Fracture)

20. Crevasses

21. Crevasses

22. The Glacial Budget
Zone of Accumulation
Zone of Ablation
Equilibrium Line

25. “fastest velocity at
equilibrium line”

26. IV. Classification of Glaciers

27. IV. Classification of Glaciers
Descriptive-based
Process-based

28. IV. Classification of Glaciers
Descriptive-based
* Cirque Glaciers
* Valley Glaciers
* Ice Sheets

29. IV. Classification of Glaciers
Descriptive-based
Process-based
1. Dynamic classification scheme
* Active
* Passive
* Dead

30. IV. Classification of Glaciers
Descriptive-based
Process-based
1. Dynamic classification scheme
* Active
* Passive
* Dead
2. Thermal classification scheme
* Temperate Glaciers

32. IV. Classification of Glaciers
Descriptive-based
Process-based
1. Dynamic classification scheme
* Active
* Passive
* Dead
2. Thermal classification scheme
* Temperate Glaciers
* Polar Glaciers
--sub polar
--high polar

33. V. Erosional Glacial Landforms

34. Cirques
Tarn Lakes
Pater Noster Lakes
Horns
Aretes
U shaped Valleys
Hanging Valleys
Fjords

35. Erosional Landforms

36. Erosional Landforms

37. Erosional Landforms

38. Cirques

39. Cirques……and Tarns

40. Arete

41. U-shaped valley

42. Hanging valley

43. Hanging valley

44. Horn

45. Fjords

46. Pater noster lakes

47. Glacial Erosion
Glacial Striations and
grooves

48. Glacial Polish

49. VI. Depositional Landforms

50. Glacial Till

52. VI. Depositional Landforms
Glacial Till
Stratified drift

53. VI. Depositional Landforms
Moraines
Lateral
Medial

54. Lateral and Medial Moraines

55. Moraines……End, Terminal, Ground

60. End Moraine

62. Terminal moraine

63. Eskers, Drumlins, Kames, Kettles, Outwash Plains, Erratics

65. B) Drumlin –

66. B) Drumlin –

67. B) Drumlin –

68. C) Kettles

69. C) Kettles

70. D) Eskers

71. D) Eskers

72. Esker

73. Kame –

74. Outwash plain

76. The Pleistocene Epoch
Milankovitch Cycles
Eccentricity
Tilting
Wobble

77. Milankovitch Cycles
Individual cycles vs. multiple cycles

78. 400,000 years of change
Note how climate slowly cools going into a glacial period.
Then rapidly warms at the end. But quickly starts cooling again.

79. 10,000 years of change

80. The Pleistocene Ice Ages:
Glacial Periods
Wisconsinan
Illinoian
Kansan
Nebraskan

82. Global sea level drop

83. Pluvial Lakes

84. J. Harlen Bretz