Chapter 1Chapter 1

Introduction to EarthIntroduction to Earth

GeographyGeography

GeographyGeography is derived from Greek for is derived from Greek for earth descriptionearth description

Physical Geography is the study of Physical Geography is the study of the earth’s composition – it’s the earth’s composition – it’s physical attributes, such as the physical attributes, such as the surface:surface:

Topography Topography Climate and soil Climate and soil VegetationVegetation Water bodiesWater bodies AtmosphereAtmosphere

Physical vs. Cultural GeographyPhysical vs. Cultural Geography

2 areas of study2 areas of study• PhysicalPhysical: things : things

you can you can touch/see/experitouch/see/experienceence

• Cultural/socialCultural/social: : why things why things happen or are happen or are the way they arethe way they are

4 Spheres4 Spheres

Atmosphere – airAtmosphere – air• Protective envelope around EarthProtective envelope around Earth

Hydrosphere – waterHydrosphere – water• Salt and fresh – necessary for lifeSalt and fresh – necessary for life

Lithosphere – landLithosphere – land• Topmost layer of the mantleTopmost layer of the mantle

Biosphere - all lifeBiosphere - all life• Flora and faunaFlora and fauna

Fundamental ConceptsFundamental Concepts

Planet Earth - as a whole:Planet Earth - as a whole: It’s relation to solar systemIt’s relation to solar system Size and shape of EarthSize and shape of Earth Geographic grid – latitude & longitudeGeographic grid – latitude & longitude Earth Sun relationsEarth Sun relations Earth Moon relationsEarth Moon relations

The Solar SystemThe Solar System

Formation of the Solar Formation of the Solar SystemSystem• Formed 4.5 to 5 billion Formed 4.5 to 5 billion

years agoyears ago• 8 planets revolve around 8 planets revolve around

the Sunthe Sun• 4 terrestrial planets 4 terrestrial planets • 4 gas giants4 gas giants• Earth is the third planetEarth is the third planet

66© 2011 Pearson Education, Inc.

Solar SystemSolar System

The Planets - 2007The Planets - 2007

MercuryMercury VenusVenus EarthEarth MarsMars JupiterJupiter SaturnSaturn UranusUranus NeptuneNeptune Pluto – on again – off againPluto – on again – off again

Ellipse vs. CircleEllipse vs. Circle

2 foci = ellipse

1 focus = circle

Earth’s Ellipse around SunEarth’s Ellipse around Sun

Shorter distance

23.523.5°° Tilt Tilt

The Equator bisects the sphere of the Earth. It is The Equator bisects the sphere of the Earth. It is a great circle

Rotation of the Earth about its axis once Rotation of the Earth about its axis once every 24 hours is partially responsible forevery 24 hours is partially responsible for

Coriolis effect tides jet lag day/night

The noon Sun is directly overhead the tropic The noon Sun is directly overhead the tropic of Cancer on of Cancer on June 21

Earth-Sun RelationsEarth-Sun Relations

SizeSize&&

shapeshapeofof

EarthEarth

Diameter = 8000 miles (radius = 4000)Diameter = 8000 miles (radius = 4000) Circumference = 25,000 milesCircumference = 25,000 miles Earth is slightly flattened at poles and wider at equatorEarth is slightly flattened at poles and wider at equator Earth is approximately 4.6 billion yrs. oldEarth is approximately 4.6 billion yrs. old

Latitude/LongitudeLatitude/Longitude Latitude and Longitude define site location on the Latitude and Longitude define site location on the

surface of the earthsurface of the earth LatitudeLatitude is used to express distance north or south is used to express distance north or south

of the equatorof the equator LongitudeLongitude shows east-west distance from the shows east-west distance from the

Greenwich meridian @ 0° to the International Date Greenwich meridian @ 0° to the International Date Line @ 180°Line @ 180°

Locations are given in degrees, minutes, secondsLocations are given in degrees, minutes, seconds For example:For example:

• Boston, MA: Lat 42.37N – Long 71.03WBoston, MA: Lat 42.37N – Long 71.03W• Boston, MA: Lat 42° 22’ 11” - Long 71° 1’ 47” Boston, MA: Lat 42° 22’ 11” - Long 71° 1’ 47” • Lawrence, MA: Lat 42.72N – Long 71.12WLawrence, MA: Lat 42.72N – Long 71.12W• Lawrence, MA: Lat 42° 43’ 12” - Long 71° 7’ 12” Lawrence, MA: Lat 42° 43’ 12” - Long 71° 7’ 12”

Major lines of latitudeMajor lines of latitude

It becomes the next day.

You are traveling west from San Francisco toward You are traveling west from San Francisco toward Seoul, when you cross the international date line Seoul, when you cross the international date line

at noon what happens?at noon what happens?

Standard Time ZonesStandard Time Zones

Established 1884Established 1884 24 time zones24 time zones Each = 15° longitudeEach = 15° longitude In international waters – strictIn international waters – strict On land can vary – political or On land can vary – political or

economic economic

Coriolis Coriolis Deflection of a moving object, caused by the

moving frame of reference on the spinning Earth

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

In the N. Hemisphere deflected to the right

In the S. Hemisphere deflected to the left

Coriolis Coriolis

SummarySummary

3434

Geography is the study of the distribution of Geography is the study of the distribution of physical and cultural attributes of Earthphysical and cultural attributes of Earth

Many sciences have branched off of geographyMany sciences have branched off of geography The scientific method is important when doing The scientific method is important when doing

scientific studiesscientific studies Earth has four primary spheres: the atmosphere, Earth has four primary spheres: the atmosphere,

the lithosphere, the hydrosphere, and the the lithosphere, the hydrosphere, and the atmosphereatmosphere

The solar system formed 5 billion years ago and The solar system formed 5 billion years ago and consists of 8 planetsconsists of 8 planets

© 2011 Pearson Education, Inc.

SummarySummary

3535

Earth is an imperfect sphereEarth is an imperfect sphere A latitude and longitude grid help identify A latitude and longitude grid help identify

locations on Earth’s surfacelocations on Earth’s surface Earth rotates on its axis in 24 hoursEarth rotates on its axis in 24 hours Earth revolves around the Sun in 365 ¼ Earth revolves around the Sun in 365 ¼

daysdays Tilt of Earth’s axis causes seasonsTilt of Earth’s axis causes seasons Equinoxes and solstices help identify Equinoxes and solstices help identify

when a seasonal transition occurswhen a seasonal transition occurs

© 2011 Pearson Education, Inc.

SummarySummary

3636

Time zones were established to have a Time zones were established to have a uniform global time systemuniform global time system

Daylight-saving time was devised to Daylight-saving time was devised to conserve energy by adding an hour of conserve energy by adding an hour of daylightdaylight

© 2011 Pearson Education, Inc.