Today

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Today

• Short Review from Tuesday
• Introduction to Earth
• Science and geography
• Four environmental spheres
• Solar system
• Size/Shape of the earth
• Earths grid
• Earth/Sun relationships (seasons)
• Survey

2
what is spatial?
REVIEW

• Part No. Quantity Description
• 102334 4 crank arms
• BIKE 102345 9 pedals
• PARTS 102098 3 headsets
• 223234 104 spokes
• --------------------------------------------------
  ---------------------------------------
• Date Address Type
• 4/06/06 1200 N Nash robbery
• CRIMES in 4/08/06 120 Ft Meyer assault
• ROSSLYN, VA 4/08/06 3400 Wilson burglary
• 4/10/06 1334 Rhodes assault

3
what is physical geography?
REVIEW
1. Appalachian Mountain Range

• form
• process

2. Cascade Mountain Range
4
Science and geography

• Scientific method
• observe something that prompts curiosity
• guess (hypothesize) whats going on
• design, predict, and conduct experiment to test
  hypothesis
• precisely identify results and formulate
  conclusions
• contribute to theory (highest order or
  understanding of a domain)

design a physicalmodel
design a computer model
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Science and geography

• Science is a self correcting process
• refinement and peer review
• The authors of your book state that they
  presents the fundamentals of physical
  geography as it is supported by scientific
  research (pg. 3)
• Can you provide examples of new evidence that
  could prompt physical geographers to change a
  theory?

6
Earths environmental spheres 

• Atmosphere gaseous envelope surrounding Earth
  (e.g., nitrogen, oxygen, argon, water vapor)
• Hydrosphere all forms of water (oceans, ice,
  fresh)
• Lithosphere inorganic solid rocks minerals
• Biosphere where living organisms reside (at/near
  surface)

Atmosphere? Hydrosphere? Lithosphere? Biosphere
?
Where are they?
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The size of Earth 
FROM http//www.rense.com/general72/size.htm
Earth diameter 7,900 miles Earth circumference
249,000 miles
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The size of Earth 
FROM http//www.rense.com/general72/size.htm
1,301,939 Earths would fit INSIDE of THE SUN!
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The size of Earth 
FROM http//www.rense.com/general72/size.htm
FROM http//www.rense.com/general72/size.htm
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The size of Earth 
FROM http//www.rense.com/general72/size.htm
FROM http//www.rense.com/general72/size.htm
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What is the shape of Earth?

• Flat ?
• A perfect sphere ?
• An oblate spheroid or ellipsoid ?
• A geoid ?

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What is the shape of Earth?

• Flat? MAYBE!
• Earth is shaped in the form of a flat
  pentagon, and thus has five corners

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What is the shape of Earth?

• A perfect sphere? NO!
• 136 km shorter trip around earth pole-to-pole
  than at equator
• Polar and equatorial radii are 21.5 km different

Sphere
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What is the shape of Earth?
What about all of the relief (highs and lows) and
topographic irregularities?
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What is the shape of Earth?
What about all of the relief (highs and lows) and
topographic irregularities?

• Grand Teton 13,770 ft. to Jackson Lake 6,776 ft.
  6,994 ft!
• Manitou Spgs. 6,200 ft. to Pikes Peak 14,115 ft.
  7,915 ft!
• Mt. Elbert 14,433 ft. to Arickaree R. 3,315 ft.
  11,118 ft!
• Mt. Whitney 14,497 ft. to Death Valley -282 ft.
  14,779 ft!
• Mt. Everest 29,035 ft. to Mariana Trench -36,198
  ft. 65,233 ft!
• Brick on 40 story building analogy

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What is the shape of Earth?
More precisely, it is a GEOID! BUT TOO SPECIFIC
for THIS COURSE!!!

• Geoid considers variations in gravity
• Considers local variations in ellipsoid
• Considers local variations in sea level

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What is the shape of Earth?

• An oblate spheroid or ellipsoid? YES! YES! YES!
  

Ellipsoid or oblate spheroid
250 other variations!
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What is the shape of Earth?
Altitude
Topography
Geoid
Sea Level
Ellipsoid
Sphere
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Of course you know about rotations and revolutions

• Earth rotates about its own axis every ___ hrs.
• Its not perfect Like a spinning top, earth
  wobbles a bit!
• Earth revolves about sun every ___ days.
• Not a perfect circle Orbit is a bit elliptical!

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Of course you know about distribution of solar
energy

• Oblique solar rays deliver less energy at the
  earth's surface than vertical rays because
• energy is spread over a larger surface
• energy passes through a thicker layer of
  reflecting and absorbing atmosphere

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Of course you know that ½ the earth is always
illuminated

• there is always a circle of illumination on the
  earth

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Earths geographic grid

• Main reference features for Earth
• - Axis of Rotation
• - North Pole
• - South Pole
• - Equator

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Earths geographic grid

• Latitude lines (parallels)
• Parallel to one another
• - Intersect longitude at 90 deg. angles

Longitude lines (meridians) - Not parallel to one
another - Intersect at the poles
From this grid (called the GRATICULE), we locate
coordinates on the earths surface.
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Earths geographic grid
Longitude - the angular measurement of distance
east or west of the Prime Meridian.
The Prime Meridian is at0o longitude. The
International Date Line is at 180o longitude
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Earths geographic grid

• Lines of longitude connect poles
• Lines of longitude are the same length
• The Prime Meridian passes through London is 0
  deg. longitude
• Places are either west or east of the Prime
  Meridian
• Longitude increase E and W to the International
  Date Line (/- 180 deg.)

East of Greenwich
Prime Meridian 0
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Earths geographic grid
Latitude Lines - angular measurements north or
south of the Equator.
North Pole, 90o N
Artic Circle - 66 1/2o N
The Equator is at0o latitude. What is the
significance of these five parallels? Why 23.5?
Why 66.5?
Tropic of Cancer - 23 1/2o N
Equator - 0o
Tropic of Capricorn - 23 1/2o S
Antarctic Circle - 66 1/2o S
South Pole, 90o S
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Background Though we have an elliptical orbit,
it does not cause seasons
93 million miles average distance
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• Background
• All planets orbit
• sun on the
• same plane.
• Pretty cool, eh?

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Earth/Sun relationships

• The earth is tilted 23.5º from the plane of the
  ecliptic. THIS TILT CONTROLS OUR SEASONS! But
  how?

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SOLSTICES SUMMER, JUNE 21 WINTER, DECEMBER 21
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EQUINOXES VERNAL, MARCH 21 AUTUMNAL, SEPTEMBER 21
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Earth/Sun relationships
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