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What is a Mercator Projection
(pronounced: mer-kâ’ter or mèr-kä’tôr)
A Mercator projection is a mathematical method of showing
a map of the globe on a flat surface. This projection was developed in 1568
by Gerhardus Mercator a Flemish geographer, mathematician, and cartographer.
Before this time, navigation charts used by sailors did not correctly account
for the recently proven fact that the world was round.
Mercator's equations allowed cartographers (map-makers) to produce charts from
which sailors could easily navigate. Mercator’s projection preserves
exactly what sailors needed -- shapes and directions; they were very
willing to accept the size distortion. On a globe, the lines of longitude (measuring east-west position) converge at the poles and the lines of latitudes (measuring north-south position) are equal distance apart. In a Mercator projection, the lines of longitude are straight vertical lines equal distance apart at all latitudes, and horizontal distances are stretched above and below the equator this stretching is exaggerated near the poles. The Mercator projection mathematically stretches vertically distances by the same proportion as the horizontal distances so that shape and direction are preserved. The projection is not useful for latitudes near the poles; J-Track's projection goes from 78 degrees north latitude to 70 degrees south latitude.
Updated February 20, 1997. Contacts