99 Geological/Earth Science Facts

My 9th grade Earth Science teacher and friend Chris Visco, had put together a list of 99 Earth Science facts (or as he put it, the "99 ways to pass the Earth Science Regents"). I thought they were very well thought out and provided a ton of basic Earth science information so I figured I would pass them on to you.

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1. The true shape of the earth is an oblate spheroid.
2. The earth's true shape is most easily confirmed by photographs from space
3. The earth appears to be perfectly round
4. Compared with its size, the earth's surface appears to be smooth
5. To determine the circumference of the earth, you need to measure the altitude of a star above the horizon from two or more locations
6. The earth's equatorial circumference is slightly larger than its polar circumference
7. The lithosphere is the earth's solid outer layer of rock
8. The hydrosphere is the thin layer of water on the earth's surface
9. The atmosphere is the thin shell of gases surrounding the earth
10. The densest sphere is the lithosphere
11. The least dense sphere is the atmosphere
12. The thickest sphere is the lithosphere
13. The thinnest sphere is the hydrosphere
14. Over time, elevations represented on a topographic map change
15. The building blocks of rocks are minerals
16. Minerals are identified on the basis of well-defined physical and chemical properties
17. Minerals are grouped into families according to their chemical composition
18. The basic unit of most minerals is the silicon-oxygen tetrahedron (pyramid shape)
19. The physical properties of minerals depends upon the arrangement and bonding of their atoms
20. Rocks are classified on the basis of their origin (bow they formed)
21. Igneous rocks form by the crystallization of molten magma or lava
22. Crystal size in igneous rocks depends on rate of cooling
23. Intrusive igneous rocks form slowly beneath the earth's surface
24. Extrusive igneous rocks form quickly on the earth's surface
25. Continents are granitic, Oceans are basaltic
26. Sedimentary rocks form from sediments, evaporation of water, and organic remains
27. Sedimentary rocks form at or near the surface of the earth
28. Fossils are found almost exclusively in sedimentary rocks
29. Metamorphic rocks form from other rocks by the action of beat and or pressure
30. Contact metamorphism occurs when molten rock comes in contact with surrounding rocks
31. Regional metamorphism occurs over large areas and is associated with mountain building
32. Earthquakes and volcanoes occur in specific zones (ring of fire, mid atlantic) ·
33. The speed of a seismic wave depends on the density of the material thru which it travels
34. Richter and Mercalli measure the strength of an earthquake
35. The Richter scale gives the power released
36. The Mercalli scale gives the damage caused
37. Plate tectonics the earth's crust is divided into pieces called plates which move
38. The three types of plate boundaries are divergent (moving way, mid ocean ridge), convergent (coming together) and transform (sliding)
39. Subduction is when one plate sinks under another forming a trench
40. Weathering occurs when rocks are exposed to the hydrosphere, biosphere, and atmosphere
41. Moist and warm climates favor chemical weathering
42. Moist and cold climates favor physical weathering
43. Weathering is slow in dry climates
44. As particle size decreases surface area increases and the rate of weathering increases
45. Soils develop as a result of weathering and biological activity
46. The primary force that drives the agents of erosion is gravity
47. The most important agent of erosion is running water
48. The amount of stream erosion depends on the velocity of a stream and the volume of water
49. Stream velocity depends on gradient and volume of water
50. The outside of a meander bend is fast and erodes. The inside of a meander bend is slow and deposits
51. As stream velocity increases, the size of the particles that can be transported increases
52. Streams carry sediments by solution, suspension, bouncing and rolling
53. The particles that settle out first are larger, most dense, and roundest
54. Water and wind deposits are sorted by size and layered
55. Gravity and glacial deposits are unsorted
56. Arid landscapes are angular. Humid landscapes are smooth
57. Glacial landscapes show U shaped valleys, depressions, irregular hills, scratched boulders
58. In undisturbed sedimentary rocks, the bottom layer is the oldest
59. Faults, folds, and intrusions are younger than the rocks they are found in
60. Index fossils are found over a wide area and existed for a short period of time
61. Geologic time is divided into units based on the fossil record
62. An unconformity is a buried erosional surface
63. Unconformities represent a gap in the geologic record
64. Radioactive isotopes decay at a predictable rate known as half 1ife
65. Carbon is used to date recent, organic remains
66. Most life forms of the geologic past have become extinct
67. As temperature increases, relative humidity decreases
68. As altitude increases, air pressure decreases
69. Wind is named for the direction it comes from
70. The closer air temperature is to the dew point the greater the chance of precipitation
71. Air in a low pressure area is warm and moist
72. Air in a high pressure area ls cool and dry
73. A rising barometer indicates good weather coming. A falling barometer indicates bad weather coming. A steady barometer indicates no change
74. Fronts occur where air masses of different temperature and humidity meet
75. The most likely areas for precipitation are the leading edges of air masses (fronts)
76. The circulation in a low pressure system is counterclockwise, toward the center, where air rise. The circulation in a high pressure system is clockwise, away from the center, where air sinks.
77. Weather systems in the U.S. usually move from west to east
78. cT warm & dry.  cP cool & dry. mT warm & moist. mP cool & moist
79. Hurricanes form over warm oceans ln summer and autumn
80. Tornadoes form in the spring where very different air masses collide
81. Hurricanes lose strength as they move over land or cool water
82. The earth rotates west to east, 15 degrees per hour, in 24 hours or in one day
83. In the U.S. the sun appears to rise in the east, move through the southern sky and set in the west
84. The earth revolves counterclockwise, 1 degree per day, in 365 ¼ days or one year
85. As a planet gets closer to the sun the faster it orbits
86. The earth’s orbit around the sun is nearly circular
87. The moon revolves around the earth, in an elliptical orbit, in approximately one month
88. The seasons are caused by the tilting of the earth’s axis and revolution around the sun
89. The intensity of sunlight varies with the angle of the sun above the horizon
90. The sun is most intense at an angle of 90 degrees
91. Shadows get longer as the sun gets lower ln the sky
92. Summer solstice: June 21.
1. The sun rises north of east.
2. The sun sets north of west.
3. The sun reaches highest altitude of year.
4. Vertical ray hits tropic of cancer.
5. NY gets approx. 16 hours of daylight.
6. North pole gets 24 hours daylight
93. Winter solstice: December 21
1. The sun rises south of east
2. The sun sets south of west
3. The sun reaches lowest altitude of year
4. Vertical ray hits Tropic of Capricorn
5. NY gets approx. 8 hours daylight
6. North pole gets 0 hours daylight
94. Equinoxes: Vernal March 21, Autumnal September 22
1. The sun rises due east
2. The sun sets due west
3. Vertical ray hits equator
4. The whole earth gets 12 hours daylight
95. The equator always receives 12 hours of daylight
96. The earth absorbs mostly short wavelength light energy. The earth reradiates mostly longer wavelength heat radiation
97. Gases such as carbon dioxide prevent the escape of heat causing the greenhouse effect
98. Marine climate cool summers, warm winters. Continental climate cold winters, hot summers
99. Leeward side of a mountain dry & warm due to compression
100. Windward side of a mountain cool & moist due to expansion