Peru's Nasca Lines Point To Water Sources, Suggest UMass Researchers

The lines were constructed in the desert in southwestern Peru about 1,500-2,000 years ago by the Nasca culture, prior to the invasion of the Incas. The lines, which are etched into the surface of the desert by removing surface pebbles to reveal the lighter sand beneath, depict birds and mammals, including a hummingbird, a monkey, and a man, as well as zigzags, spirals, triangles, and other geometric figures. Called "geoglyphs," the elaborate figures are located about 250 miles south of Lima, and measure up to 1.2 miles in length. Their meaning has been the object of centuries of speculation. Some experts have hypothesized that the figures had ceremonial or religious functions, or served as astronomical calendars. But a slate of scientific tests has led the UMass team to theorize that at least some of the geometric shapes mark underground water.

"Ancient inhabitants may have marked the location of their groundwater supply distribution system with geoglyphs because the springs and seeps associated with the faults provided a more reliable and, in some instances, a better-quality water source than the rivers. We're testing this scientifically," said Mabee. "The spatial coincidence between the geoglyphs and groundwater associated with underground faults in the bedrock offers an intriguing alternative to explain the function of some of the geoglyphs."

Proulx, who has studied the region for decades, notes that the symbols on the biomorphs (figures of animals, plants, and humans) and on Nasca pottery are almost identical. "There are representations of natural forces," he says, "Not deities in the Western sense, but powerful forces of sky and earth and water, whom they needed to propitiate for water and a good harvest."

The team has studied the drawings and taken water samples during three separate journeys to Peru, over the past five years. The research has been funded by a University of Massachusetts Healy grant, the National Geographic Society, and the H. John Heinz Charitable Trust.

"So far, the tests indicate that the underground faults provide a source of reliable water to local inhabitants. The water, in comparison with available river water, is better-quality in terms of pH levels, magnesium, calcium, chloride and sulfate concentrations," Mabee said.

Proulx carried out an archaeological survey of more than 128 sites in the drainage area, in conjunction with the geological research. His discoveries provided data for another piece of the puzzle — many archaeological sites were constructed near water-bearing faults and used this important secondary source of water.

The team was able to map the water's sources, and found that in at least five cases, the wells and aquifers corresponded with geoglyphs and archaeological sites. "They always seem to go together," said Mabee.