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  The ULTIMATE Review Sheet

For Regents Earth Science   

Density Energy Ground Water / Erosion Geologic History
Changes Insolation and the Seasons Deposition Landscape Development
Shape of the Earth Weather / Fronts Minerals and Rock Facts You MUST Know
Astronomy Climate The Dynamic Crust Other Review Sites


1.        The same substance always has the same density, no matter what the size.

2.      As pressure increases, density increases.

3.       As temperature increases, density decreases.

4.      Water expands when it freezes.

5.       Water is densest at 4oC as a liquid.  

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6.       Most changes in the environment are cyclic.  

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Shape of the Earth/Measuring the Earth

7.       The true shape of the earth is an Oblate Spheroid.  It is flattened at the poles and bulging at the equator.

8.       The best model for the shape of the earth is a sphere.

9.       The best evidence for the spherical shape of the earth are pictures from space.

10.    Positions on earth are located using the coordinate system of latitude and longitude.

11.      Latitude lines (parallels) are drawn from east to west and measured from north to south (Equator)

12.    Longitude lines (meridians) are drawn from North Pole to South Pole and are measure from east to west (Prime Meridian).

13.    Latitude is based on the altitude of Polaris, (the North Star).

14.    Longitude is based on the observations of the sun (also a star).

15.    The closer the isolines (isotherms, isobars, contour lines…), the steeper the gradient (slope).

16.    Contour lines bend upstream as they cross a stream or river.  

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17.     The earth ROTATES on its axis from west to east (counterclockwise).

18.    One Earth rotation takes approximately 24 hours.  One hour equals 15o of rotation.

19.    The earth REVOLVES around the sun counterclockwise.

20.  One earth revolution takes 365.26 days in a slightly elliptical orbit.

21.    All planets orbits are in the shape of an ellipse with the sun at 1 focus point.  (This includes moons, satellites, comets…).

22.  All celestial objects appear to move from east to west.

23.  The moon has phases because of the angle at which we view its surface.

24.  ½ the moon is always lit by the sun (we can only ever see 1 side of the moon).

25.  The moon phases are: (waxing) crescent-quarter-gibbous-full- (waning) gibbous-quarter-crescent-new (sing it loud!).

26.  The moon waxes and wanes from right to left.

27.   The moon’s phases take 29½ days to complete the cycle (about 1 month).

28.  The planets appear to move backwards (retrograde motion) as the earth passes them it its orbit.

29.  The seasons are due to the tilt of the earth’s axis, 23½ o.

30.  Summer Solstice (“sun-stop”) June 21st  - longest day of the year in NYS – sunrise north of east.  Vertical ray located at Tropic of Cancer, 23½ o north latitude.

31.    Winter Solstice – December 21st – shortest day of the year in NYS – sunrise south of east.  Vertical ray located at the Tropic of Capricorn 23½ o south latitude.

32.  Equinoxes (equal night) - September 23rd – Autumnal, March 21st – Vernal.  Vertical ray located at the equator.  12 hours of daylight and 12 hours of darkness everywhere on earth.

33.   The Equator always has 12 hours of daylight (everyday).

34.  The lower the altitude of the sun the longer the shadow.

35.   At noon in NYS a shadow will always point north.

36.   Evidence for rotation is the Foucault Pendulum – appears to change direction, and the Coriolis Effect – deflects winds to the right in the Northern Hemisphere.

37.   Earth is closer to the sun (perihelion) around January 3rd or 4th (winter).

38.   The closer the planet is to the sun, the faster it travels in its orbit.  Why?

39.   Geocentric model – Earth centered, Ptolemy.

40.  Heliocentric model – Sun centered, Copernicus.  

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41.    Temperature is the average KE of the molecules in a substance.

42.  Black (dark) absorbs, white (light) reflects, rough absorbs, smooth reflects.

43.  Conduction: energy transfer through molecular collisions; solids in contact.

44.  Convection: energy transfer through differences in density.  Circulating currents of gasses and liquids.  (Occurs in the atmosphere and asthenosphere).

45.  Radiation: energy transfer through space.  How light energy travels here from the sun and the stars.

46.  Energy moves from the source (highest temp.) to the sink (lowest temp.).

47.   Kinetic Energy (KE): energy of motion.  As velocity increases, KE also increases.

48.  Potential Energy (PE): energy of position. As the position of an object increases away from the center of the earth, PE increases.

49.  There is NO temperature change during a phase change.  

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Insolation and the Seasons

50.  Earth absorbs short waves (visible light).

51.    Earth radiates long waves (infrared energy).

52.  Carbon Dioxide (CO2), methane (CH4), and water vapor are good absorbers of infrared energy.  (Causes the Greenhouse Effect).

53.   A good absorber of electromagnetic energy (EME) is also a good radiator of EME.

54.  Hottest days of the year are usually 1-month after the day of maximum insolation, June 21st , “seasonal temperature lag”.

55.   Hottest time of any 24-hour period is usually 1 - 2 hours after noon (max insolation), “daily temperature lag”.

56.   Summer Solstice in the northern hemisphere is 21 June.  Duration of insolation is the longest.  Intensity of insolation strongest. 
24 hours of daylight at 90o North.

57.   Winter Solstice in the northern hemisphere is 21 December.   Duration of insolation is the shortest.  Intensity of insolation is the least.     24 hours of daylight at 90o South.

58.   The equatorial region always has approximately 12 hours of daylight all year.  

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59.   As temperature increases, air pressure decreases.

60.  As humidity (moisture content of the air) increases, air pressure decreases.

61.    As altitude/elevation increases, air pressure decreases.

62.  High Pressure = sinking air currents, dry conditions, little to no clouds.

63.   Low Pressure = rising air currents, moist conditions, increase in cloud development.

64.  Wind occurs due to differences in air pressure.

65.   Wind always moves from regions of high pressure to regions of low pressure perpendicular to the isobars.  
Isobars close together = steep pressure gradient = high wind speeds.

66.   Wind is named by the direction it is coming from.

67.   Surface High Pressure (anticyclones) = Clockwise and divergent winds.

68.   Surface Low Pressure (cyclones) = Counterclockwise and convergent winds.

69.   The closer the dew point temperature gets to the air temperature the greater the chance for precipitation.  
Dew point = Air temp
> brings 100% humidity!!

70.   In the middle latitudes (U.S.), weather moves from the west to the east (northeast).  Prevailing Westerlies.

71.     Precipitation occurs when: warm, moist air rises,

                cools adiabatically (due to expansion),

                reaches the dew point temp.,

                condensation occurs (on condensation nuclei),

                the droplets collect in masses (cloud formation)

                when the drops are large enough = precipitation.

72.   Air cools adiabatically as it rises due to expansion from the higher  atmospheric pressure at low elevations to the lower atmospheric pressures at higher elevations.

73.   Air warms adiabatically as it sinks due to compression by the heavier atmospheric pressure at lower elevations.

74.   Air masses are characterized by their TEMPERATURE and MOISTURE characteristics.

75.   The leading edge of the air mass is called the FRONT.

76.   See a :         Cold Front
              Warm Front
                 Stationary Front
                 Occluded Front

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77.  Mountains force air up the windward ( cool/moist) side and down the leeward (warm/dry) side (the Orographic Effect).

78.  Large bodies of water moderate coastal climates, (warmer winters, cooler summers).  

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Ground Water/Erosion

79.  Porosity (percentage of empty space) does NOT depend on particle size.

80.  Permeability, the ability to flow through ground material, pores must be connected.  As particle size increases, permeability also increases.

81.  Capillarity, Upward movement of water through the ground depends on surface area.  As Particle size decreases, capillarity increases.

82.  Gravity is the main FORCE behind all erosion.

                weathering is the breakdown of rock into sediments
         erosion is the transporting of those sediments

83.  RUNNING WATER (streams, rivers) is the number 1 AGENT of erosion in NYS.  

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84.  Water and wind create sorted deposits of sediments.  Gravity and Glaciers form unsorted deposits of sediments.

85.  A common glacial deposit is called a moraine.  Glacial deposits are unsorted.

86.  Stream velocity depends on SLOPE and DISCHARGE (the amount of water moving through the stream at any one time).

87.  In a meander, velocity is greater (therefore erosion is greater also) on the OUTSIDE of the curve.

88.  Streams and rivers carve a V-shaped valley.  Glaciers carve a U-shaped valley.

89.  Heavy-Dense (large) particles settle to the bottom of a calm body of water faster.

90.  Colloids (clay-sized particles) remain suspended in bodies of water for long periods of time.

91.  In graded bedding (vertical sorting) the largest sediments are on the bottom.  

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Minerals and Rock

92.  Sedimentary rocks (strata) form (flat) horizontal layers.

93.  Igneous rock (fire-formed) are classified by texture (grain size).  Coarse (large) grains = Intrusive - (cooled slowly below surface).  Fine (small) grains = Extrusive (cooled quickly).  Glassy (no visible crystals) = Extrusive.

94.  Metamorphic Rock – changed by heat and/or pressure.  Shows banding/foliation (stripes) and distorted structure.  Higher density, very resistant rock.

95.  The formation of igneous rock causes contact metamorphism.  Extrusion – bottom only affected, Intrusion – top and bottom affected.

96.  All minerals properties are due to the internal arrangement of the atoms.

97.  Silicon and oxygen form earth’s basic mineralogical structural unit – the tetrahedron.  

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The Dynamic Crust

98.  Subsidence – the sinking of the crust

99.  Uplift – the lifting of the crust (forms mountains...)

100.   Earth’s plates move due to convection currents in the upper-mantle (asthenosphere)

101.          At the Mid-Ocean ridges (spreading center) new crust is created, age of the rock increases as distance from the ridge increases. Divergent Plate Boundary

102.          Ocean trenches (subduction zone) where old crust is destroyed.  Convergent Plate Boundary

103.            P-waves travel faster than S-waves.

104.           P-waves travel through solids and liquids. 

105.            S-waves travel through solids only (can’t go through the outer core).

106.            Need a minimum of three (3)  seismograph stations to determine the location of an epicenter.

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Geologic History

107.        Undisturbed rock – oldest layer is on the bottom (superposition).

108.            Intrusions and faults are younger than the rock they cut through.

109.            Unconformity: buried erosional surface – a gap in the  rock record.

110.          Carbon 14 (14C) – dates recent organic (once living) remains up to 50,000years old.
        *Radioisotope decay is constant and unaffected by environmental changes. 

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Landscape Development

111.   Landscapes are  dependant  on bedrock structure and climate.

112. Arid landscapes – steep slopes, angular features.

113.  Humid Landscapes – smooth, rounded slopes and features.

114. The Catskills ARE NOT mountains (dissected plateau – horizontal bedrock).

115.  The Age of the earth is 4.6x109 years old, 4.6 billion years old, 4,600 million years.  

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Earth Science Facts you MUST know:  

1.        When you cut an object into pieces, you don’t change its density.

2.      The Altitude of Polaris is equal to the latitude of the observer.

3.       The Coriolis force deflects currents to the right in the northern hemisphere.

4.      Condensation = phase change from gas to liquid – remove heat energy. 

No temperature change.

5.       Freezing = phase change from liquid to solid – remove heat energy.

No temperature change.

6.       Boiling (vaporization) = liquid to gas – add heat – needs the most energy.

No temperature change.

7.       There is no temperature change during a phase change (se 4, 5, and 6).

8.       Low Pressure = lousy, cloudy, humid weather, rising air currents, counterclockwise and convergent circulation.

9.       High Pressure = happy, cloudless, dry weather, sinking air currents, clockwise and divergent circulation.

10.    Weather moves from west to east (northeast trend) in the United States.

11.      Porosity is not affected by particle size.

12.    Potential Evapotranspiration (Ep) depends on TEMPERATURE ONLY!

13.    Minerals have different properties due to their internal arrangement of atoms.

14.    Marine fossils (seashells…) on mountain tops indicate that the land has been uplifted.

15.    The Equatorial regions receive 12 hours of daylight EVERYDAY.

16.    Always remember: “when it doubt, take it out -------your Reference Tables (that is)!!!”

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