The Michigan State University Map Library now has on display three copper plates used to make the 1912 USGS topographic map of the Lansing, Michigan area. “From the 1880s to the 1950s, the U.S. Geological Survey used engraved copper plates in the process of printing topographic and geographic quadrangle maps. Copper alloy engraving plates were inscribed with a mirror image of the points, contour lines, symbols, and text that constitute a topographic map. Each plate was inscribed with details for a single color of ink.” [via]
Tag: topo maps
New Moon Maps
Two stunning maps of the Moon have been released by the USGS, both based on data collected by the Lunar Reconnaissance Orbiter: one an image mosaic assembled from visual imagery, the other (above) a colour-coded topographical map derived from laser altimeter data. Via io9.