prime meridians
Zero-degree longitude lines
Prime meridians are lines of longitude designated as zero degrees, from which other longitudes are measured east and west.
While any meridian could theoretically serve this function, the line passing through Greenwich, England has been the international standard since 1884.
The prime meridian divides the Eastern and Western Hemispheres.
- coordinatesLocation-specifying number pairs
- meridiansPole-to-pole geographic lines
- great circleMaximum spherical circumference
- chronometersPrecise time-measuring instruments
- time zonesRegional clock-setting divisions
longitude · baseline · geodesy · astrolabes · observatories · exploration · Greenwich · Royal Observatory · navigation · geographic coordinates · timekeeping · map projections · reference frames · sextants · cartography · world map · azimuth · compass rose
prime meridiansequator
Midpoint circle of rotation
latitude lines · parallels · lines of latitude · tropics · Arctic Circle
prime, meridian, primal, primer, primary, primarily, primacy, primitive, primordial