By Sid Perkins
People have long known that the world isn’t flat. Now, an innovative field survey of the world’s largest salt flat—a New Jersey–size playa high in the Andes—reveals that the barren expanse unexpectedly has minuscule variations in topography.
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Previous field surveys of southwestern Bolivia’s Salar de Uyuni hadn’t detected any variations in elevation, says Adrian A. Borsa, a geophysicist at the Scripps Institution of Oceanography in La Jolla, Calif. “On topographical maps, the entire region lies in between contour lines,” he notes. Even data gathered during the Shuttle Radar Topography Mission in 2002 (SN: 2/23/02, p. 126) weren’t accurate enough to discern the subtle ridges and valleys of the 9,000-square-kilometer region.