Globe : Latitudes and Longitudes

• The Globe

  • Definition: True model of the Earth
  • Features:
    • Miniatures form
    • Can be rotated
    • Shows countries, continents, and oceans on a smaller scale
  • Axis: A needle fixed through the globe in a tilted manner (Axis)
  • Poles: Two points on the globe through which the needle passes (North Pole and South Pole)
  • Equator: Imaginary line dividing the globe into two equal halves

• Important Parallels of Latitudes

  • Definition: Parallel circles from the equator up to the poles (Latitudes)
  • Measurement: Measured in degrees (°)
  • Equator: 0° latitude (represents the zero degree latitude)
  • Major Zones & Lines:
    • Tropic of Cancer (23½° N)
    • Tropic of Capricorn (23½° S)
    • Arctic Circle (66½° N)
    • Antarctic Circle (66½° S)

• Heat Zones of the Earth

  • Torrid Zone:
    • Receives maximum heat
    • Mid-day sun is exactly overhead at least once a year
  • Temperate Zones (North and South):
    • Moderate temperatures
    • Mid-day sun never shines overhead
  • Frigid Zones (North and South):
    • Very cold
    • Sun does not rise much above the horizon

• Longitudes

  • Definition: Lines of reference running from the North Pole to the South Pole (Longitudes)
  • Prime Meridian:
    • Longitude passing through Greenwich (British Royal Observatory)
    • Value is 0° Longitude
    • Divides Earth into Eastern Hemisphere and Western Hemisphere
  • Extent: 180° eastward and 180° westward (Total 360 meridians)

• Longitude and Time

  • Rotation: Earth rotates from west to east
  • Local Time: Rises and sets every day; measured by shadows cast by the sun
  • Time Difference:
    • Earth rotates 360° in 24 hours (15° in one hour, 1° in four minutes)
  • Standard Time:
    • Necessary to adopt local time of some central meridian for a country
    • Indian Standard Time (IST): Taken as 82½° E meridian (5 hours and 30 minutes ahead of Greenwich Mean Time)