Transcript ch_1

Chapter 1
Introduction to Earth
Geography
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Geography is derived from Greek for
earth description
Physical Geography is the study of
the earth’s composition – it’s
physical attributes, such as the
surface:
Topography
 Climate and soil
 Vegetation
 Water bodies
 Atmosphere
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Physical vs. Cultural Geography
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2 areas of study
• Physical: things
you can
touch/see/experi
ence
• Cultural/social:
why things
happen or are
the way they are
4 Spheres
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Atmosphere – air
• Protective envelope around Earth
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Hydrosphere – water
• Salt and fresh – necessary for life
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Lithosphere – land
• Topmost layer of the mantle
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Biosphere - all life
• Flora and fauna
Fundamental Concepts
Planet Earth - as a whole:
 It’s relation to solar system
 Size and shape of Earth
 Geographic grid – latitude & longitude
 Earth Sun relations
 Earth Moon relations
The Solar System
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Formation of the Solar
System
• Formed 4.5 to 5 billion
years ago
• 8 planets revolve around
the Sun
• 4 terrestrial planets
• 4 gas giants
• Earth is the third planet
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Solar System
The Planets - 2007
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Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto – on again – off again
Ellipse vs. Circle
2 foci = ellipse
1 focus = circle
Earth’s Ellipse around Sun
Shorter distance
23.5° Tilt
The Equator bisects the sphere of the Earth. It is a
great circle
Rotation of the Earth about its axis once
every 24 hours is partially responsible for
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Coriolis effect
tides
jet lag
day/night
The noon Sun is directly overhead the tropic
of Cancer on June 21
Earth-Sun Relations
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Diameter = 8000 miles (radius = 4000)
Circumference = 25,000 miles
Earth is slightly flattened at poles and wider at equator
Earth is approximately 4.6 billion yrs. old
Size
&
shape
of
Earth
Latitude/Longitude
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Latitude and Longitude define site location on the
surface of the earth
Latitude is used to express distance north or south
of the equator
Longitude shows east-west distance from the
Greenwich meridian @ 0° to the International Date
Line @ 180°
Locations are given in degrees, minutes, seconds
For example:
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Boston, MA: Lat 42.37N – Long 71.03W
Boston, MA: Lat 42° 22’ 11” - Long 71° 1’ 47”
Lawrence, MA: Lat 42.72N – Long 71.12W
Lawrence, MA: Lat 42° 43’ 12” - Long 71° 7’ 12”
Major lines of latitude
You are traveling west from San Francisco toward
Seoul, when you cross the international date line
at noon what happens?
It becomes the next day.
Standard Time Zones
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Established 1884
24 time zones
Each = 15° longitude
In international waters – strict
On land can vary – political or
economic
Coriolis
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Deflection of a moving object, caused by the
moving frame of reference on the spinning Earth
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As air warms, expands, and rises at the equator,
it moves toward the pole, but instead of traveling
in a straight path, the air is deflected eastward
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In the N. Hemisphere deflected to the right
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In the S. Hemisphere deflected to the left
Coriolis
Summary
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Geography is the study of the distribution
of physical and cultural attributes of Earth
Many sciences have branched off of
geography
The scientific method is important when
doing scientific studies
Earth has four primary spheres: the
atmosphere, the lithosphere, the
hydrosphere, and the atmosphere
The solar system formed 5 billion years ago
and consists of 8© 2011
planets
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Summary
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Earth is an imperfect sphere
A latitude and longitude grid help
identify locations on Earth’s surface
Earth rotates on its axis in 24 hours
Earth revolves around the Sun in 365 ¼
days
Tilt of Earth’s axis causes seasons
Equinoxes and solstices help identify
when a seasonal transition occurs
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Summary
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Time zones were established to have a
uniform global time system
Daylight-saving time was devised to
conserve energy by adding an hour of
daylight
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