Spherical Earth to flat map dilemma (or, how to

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Spherical Earth to flat map dilemma (or, how to Powered By Docstoc
					Spherical Earth to flat map dilemma (or, how to make your own groovy globe)
The view of the Earth above is derived from NOAA AVHRR satellite imagery which images the entire globe every 24 hours. It clearly illustrates the ‘spherical earth’
to ‘flat map’ dilemma faced by cartographers. The spherical earth has been peeled like an orange so that the whole earth can be seen on a flat sheet of paper. The
result is an earth composed of a series of 12 strips called ‘gores’ which are only joined around the equator. Such map projections are termed ‘interrupted’
projections because they have gaps in them. Many such projections exist, but they have limited practical application – you cant navigate across gaps! Cartographers
have therefore mathematically transformed the globe to produced a vast number of un-interrupted map projections by which the spherical earth can be represented
on a flat sheet of paper without gaps. While aesthetically more pleasing, they contain a number of distortions relating to shape, area, distance and bearing.

Print this map out on a colour printer using A4 photo or glossy paper (best quality). Using a pair of scissors, carefully cut around all the gores, removing all the white
bits. Then, use a small square of sticky tape (on the underside/back) to join all the North pole gores together (use the land boundaries on adjacent gores as a guide).
Join the two equator panels together and then all the South pole gores. The result (with care) should be a spherical earth as seen from space.