LONGITUDE AND LATITUDE

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LONGITUDE AND LATITUDE

• NAVIGATION THE EARTHS SURFACE

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DETAILS OF BOTH

• LONGITUDE
• DRAWN IN NORTH-SOUTH DIRECTION AND CALLED
  MERIDIANS
• START AT PRIME MERIDIAN (LINE FROM NORTH POLE TO
  GREENWHICH, ENGLAND)
• MEASURE BETWEEN 0 DEGREES AND 180 DEGREES
• USE EAST AND WEST TO DETERMINE WHICH HEMISPHERE

• LATITUDE
• DRAWN IN EAST-WEST DIRECTION AND CALLED PARALLELS
• START AT EQUATOR (CENTER OF GLOBE)
• MEASURE BETWEEN 0 DEGREES AND 90 DEGREES
• USE NORTH OR SOUTH TO DETERMINE WHICH HEMISPHERE

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MAP ELEMENTS

• UNDERSTANDING PARTS OF A MAP

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DISTANCE SCALES

• HELPS DETERMINE REAL DISTANCES BETWEEN POINTS
• DISTANCES VARY GREATLY DEPENDING UPON SCOPE OF
  MAP
• USUALLY MEASURE IN MILES, KILOMETERS OR BOTH

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• LEGEND/KEY
• IDENTIFIES SYMBOLS ON A MAP AND WHAT THEY
  REPRESENT
• CAN SHOW COLORS THAT REPRESENT ELEVATION
• DIRECTIONAL INDICATOR
• SHOWS EAST, WEST, NORTH OR SOUTH
• CALLED COMPASS ROSE
• CAN BE SHOWN USING ONLY NORTH
• TOP OF MAP ALWAYS NORTH

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MAP PROJECTIONS

• DRAWING THE EARTH ON A FLAT SURFACE

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GENERAL INFO

• MANY TYPES OF PROJECTIONS
• ALL HAVE SOME DISTORTION
• HIGHER LATITUDES USUALLY MOST DISTORTED
• DIRECTION, SHAPE OR DISTANCE TYPICALLY DISTORTED
• SOME DISTORT ONLY ONE OR TWO ELEMENTS
• MOST COMMON PROJECTIONS ARE CYLINDRICAL, CONIC
  AND FLAT-PLANE

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CYLINDRICAL PROJECTIONS

• DESIGNED AS IF CYLINDER SURROUNDS GLOBE BUT
  TOUCHES ONLY AT EQUATOR
• ACCURATE LONGITUDE BUT DISTORTS LATITUDE
• SHAPES DISTORTED TOWARD POLES
• INCLUDES MERCATOR PROJECTION
• DIRECTIONS HIGHLY ACCURATE SO VALUABLE FOR
  NAVIGATION

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FLAT-PLANE PROJECTIONS

• PAPER TOUCHES GLOBE AT ONE POINT
• PROJECTION FROM MIDDLE OF GLOBE TO PAPER
• USEFUL FOR SMALL REGIONS ONLY
• CANNOT USE FOR ENTIRE GLOBE
• SHOWS GREAT CIRCLE ROUTES
• VALUABLE FOR NAVIGATION
• LIMITED DISTORTION

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CONICAL PROJECTIONS

• CONE COVERS GLOBE WITH LIGHT PROJECTIONING FROM
  CENTER
• ACCURATE AT AREAS CONE TOUCHES, BUT DISTORTS AT
  FURTHER DISTANCES
• SHOWS ONLY ONE HEMISPHERE
• RETAINS TRUE SIZES AND SHAPES
• USEFUL FOR AREAS WITH LONG EAST-WEST DIMENSIONS

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MATHEMATICAL PROJECTIONS

• NEW TO GEOGRAPHY
• USES MATH TO SHOW AREAS
• SHOWS EARTHS CURVATURE
• HAS LEAST AMOUNT OF DISTORTION FOR ENTIRE GLOBE
• DIFFICULT TO DEVELOP
• BECOMING MORE POPULAR