1. 1 Geology 1001/1101 Sec 003 Chris Paola Class 12: climate and glaciation

2. 2 Chapter 10 THE CLIMATE SYSTEM AND GLACIATION

3. 3 Key ideas about climate & glaciation Much of Minnesota’s landscape has been sculpted by glaciers Glacial cycles are controlled by variation in Earth’s orbit on time scales of 10,000 – 100,000 yr Climate  weather; climate is long-term average of weather

4. 4 Climate: planetary controls Distance from Sun Albedo (reflectivity or “whiteness”) Atmosphere (greenhouse effect) Orbital properties Plate configuration (mainly due to effect on ocean circulation)

5. 5 Climate: geographic controls Distance from equator Average air flow & pressure Distance to the ocean Prevailing wind relative to mountains & ocean

6. 6 Hot Cold NOT distance to Sun! 3,900 miles 92,900,000 miles

7. 7 all sunlight that hits Earth’s surface

8. 8 10% of sunlight spread across 6.5% of sunlit surface at equator, Earth’s surface is almost perpendicular to sunlight, so energy is concentrated in small area

9. 9 10% of sunlight spread across 6.5% of sunlit surface ~ 150% of average intensity at equator, Earth’s surface is almost perpendicular to sunlight, so energy is concentrated in small area

10. 10 10% of sunlight spread across 6.5% of sunlit surface 10% of sunlight spread across 20.5% of sunlit surface ~ 150% of average intensity at poles, Earth’s surface slopes away from sunlight, so energy is spread across a greater area

11. 11 10% of sunlight spread across 6.5% of sunlit surface 10% of sunlight spread across 20.5% of sunlit surface ~ 150% of average intensity < 50% of average intensity at poles, Earth’s surface slopes away from sunlight, so energy is spread across a greater area

12. 12 Hot Cold due to the angle of the Earth’s surface

13. 13 Global air flow determines large- scale rainfall patterns Mars: one cell per hemisphere

14. 14 Earth: 3 cells per hemisphere wet dry

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20. 20 Energy and power Energy (work) –Joules –BTUs: 1 BTU = 1055 J –Kilowatt-hour: 1 KWH = 3600000 J –Calorie (food): 1 Cal = 4187 J Power: energy per time (energy rate) –1 Joule/sec = 1 Watt –1 HP = 746 Watt US energy consumption (power), per capita: 11.4 kW (11,400 Watt)

21. Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company

22. 99% of air mass

23. 23 Importance of the ocean in climate Heat storage (heat capacity of water >> that of air) Heat and moisture transport

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26. 26 Ocean currents

27. 27 Importance of the ocean in climate Heat storage (heat capacity of water >> that of air) Heat and moisture transport now onto the cryosphere…

28. Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company

33. 33 A side note: Ice and sea level

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37. 37 El Niño Warm, rising air here  lo pressure  helps maintain the wind pattern

38. 38 El Niño movie

39. 39 Part II: glaciation

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41. Movies

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44. Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company

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67. 67 Minnesota in the ice age Thanks to MN State U

68. 68 Minnesota in the ice age

69. 69 Minnesota in the ice age

70. 70 Minnesota in the ice age

71. 71 Minnesota in the ice age

72. 72 Minnesota in the ice age

73. 73 Minnesota in the ice age

74. 74 Minnesota in the ice age

75. 75 Minnesota in the ice age

76. 76 Minnesota glacial features

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78. 78 Minnesota glacial features Satellite image

79. 79 Minnesota glacial features Thanks to geologyclass.org

80. 80 Minnesota glacial features Moraine map, S Minnesota Big Stone Moraine, Traverse Cty End moraine, Freeborn Cty

81. 81 Minnesota glacial features Superior Lobe till, central MN, thanks to Karen Kleinspehn

82. 82 Minnesota glacial features Drumlin

83. 83 Minnesota* glacial features Drumlins *OK, Saskatchewan

84. 84 Minnesota* glacial features Drumlin field near Green Bay *OK, Wisconsin

85. 85 Minnesota glacial features Drumlin?

86. 86 Minnesota* glacial features Esker, Oakwood Lake *OK, S. Dakota

87. 87 Minnesota glacial features Esker

88. 88 Minnesota glacial features Esker, Finlayson MN

89. 89 Minnesota* glacial features Esker *OK, Wisconsin

90. 90 Speaking of glaciers and volcanoes… Word of the day: jokulhlaup

91. 91 Jokulhlaup Former bridge

92. 92 Our own version… Montana/Idaho glacial lakes

93. 93 Channeled scablands Eastern WA

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95. 95 Evidence for a similar flood in the English channel (S. Gupta, Imperial College London)

96. 96 Longer history and causes of glaciation

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108. 108 favors glaciation 100 kyr

109. 109 Lower solar intensity in NH 41 kyr

110. 110 NH summer when Earth farthest from Sun NH winter when Earth farthest from Sun: favors glaciation 23 kyr

111. Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company