how many latitude lines are there

Geographic Coordinates: Lines of Latitude

Latitude, also known as parallels, is a geographic coordinate that specifies the north–south position of a point on the Earth's surface. Latitude is an angle which ranges from 0° at the Equator to 90° (North or South) at the poles. Lines of constant latitude, or parallels, run east–west as circles parallel to the equator.

Defining Latitude

Latitude is typically expressed in degrees (°), with minutes (') and seconds (") used for greater precision. North latitudes are indicated with "N" (or a positive sign), and south latitudes are indicated with "S" (or a negative sign). The angular distance is measured from the center of the Earth.

Key Parallels of Latitude

  • Equator (0°): The reference line for latitude, dividing the Earth into the Northern and Southern Hemispheres.
  • Tropic of Cancer (23.5° N): The most northerly latitude at which the sun can appear directly overhead at noon.
  • Tropic of Capricorn (23.5° S): The most southerly latitude at which the sun can appear directly overhead at noon.
  • Arctic Circle (66.5° N): The southernmost latitude at which the sun can remain continuously above or below the horizon for 24 hours.
  • Antarctic Circle (66.5° S): The northernmost latitude at which the sun can remain continuously above or below the horizon for 24 hours.
  • North Pole (90° N): The northernmost point on Earth.
  • South Pole (90° S): The southernmost point on Earth.

Representation and Spacing

Lines are theoretical constructs used for mapping and navigation. The distance between each degree of latitude is approximately 111 kilometers (69 miles). Because the Earth is not a perfect sphere (it's an oblate spheroid), this distance varies slightly. For many practical applications, a degree of latitude is approximated as a constant value. Higher resolution coordinates use minutes and seconds. One minute of latitude is approximately 1.85 kilometers (1.15 miles, or 1 nautical mile), and one second of latitude is approximately 30 meters (98 feet).

Use in Geographic Coordinate Systems

Latitude is used in conjunction with longitude to specify the precise location of any point on Earth. The combination of latitude and longitude provides a unique geographic coordinate system.