The parallels are imaginary circular lines perpendicular to the Earth’s axis, and the reference is the zero parallel, or equator. They are used to determine latitude, which is the angular distance between the equatorial line and any point on the planet.
Meridians are semicircular imaginary lines that pass through the North and South Poles. They are used to measure the longitude of a point on Earth with respect to the 0 meridian or Greenwich meridian.
|definition||Lines created by man for geographic purposes. They have a circular shape and are perpendicular to the Earth’s law.||Lines created by man for geographic purposes. They have a semicircular shape and cross the Earth by its poles.|
|Points of reference||Ecuador||Greenwich meridian|
What are parallels?
The parallels are man-made lines perpendicular to the Earth’s axis from the North Pole to the South Pole. Each of these lines is numbered, from 0º, which is the equator or equatorial line (the only line that is a circle in strict terms, and which crosses the center of the globe), to 90º at the North Pole and the South Pole
The equator, or parallel 0º, divides the planet into two hemispheres: North and South. It is complemented by other 4 main parallels, with which a distinction is made, since they correspond to a specific position of the Earth, with respect to its orbit of the Sun:
- Arctic Circle: it is the parallel located further north. This parallel is the area where the polar night (December) and the midnight sun (June) of the Northern Hemisphere take place.
- Tropic of Cancer: it is the most northerly parallel, characterized because it is the place where the Sun reaches its zenith, during the June solstice.
- Tropic of Capricorn: it is the southernmost parallel in which the Sun reaches its zenith, during the December solstice.
- Antarctic polar circle: it is the southernmost parallel, where the polar night (June) and the midnight sun (December) occur in the Southern Hemisphere.
Parallels allow you to determine the North or South position of any point on the planet with respect to the equator, which is known as latitude.
What are meridians?
The meridians are imaginary lines, which go from the North Pole to the South Pole, so they have the shape of semicircles. They divide the Earth into two hemispheres: Eastern and Western.
There are 360 meridians: 180 west and 180 east of the prime meridian. The main ones are:
- Greenwich meridian: receives this name in honor of the contributions of the Greenwich observatory, in London. In addition, this parallel “passes” through the location of said observatory. Also known as the 0 meridian.
- anti meridian: so named because it opposes the Greenwich meridian, forming an angle of 180 degrees with respect to the 0º meridian. It is also known as 180 meridian.
Since 1884 the 0º meridian has been used to establish world time zones. From it, and towards the east, the hour increases and towards the west it decreases.
For its part, the antimeridian is the reference point for the international date line.
The distance from any point on the planet with respect to the 0º meridian, either east or west, is known as longitude.