Environmentalists bemoan the clearcutting of the Amazon rainforests. But an unexpected bonus has turned up: Beneath cleared jungle archaeologists are uncovering mysterious geometric designs carved into the earth.

With the help of satellite imagery from Google Earth, Brazilian archaeologists are finding more and more of the earth carvings, called geoglyphs, in the Amazon rainforest.

According to a story on environmental blog TreeHugger, The geoglyphs are believed to have been sculpted by ancient people from the Amazon region around 700 years ago, though their purpose is still unknown. So far, nearly 300 geoglyphs have been identified, but with advances in satellite imaging — and increased clearing of the jungle coverage — scientists are hoping to discover many more of these strange, geometric designs.

The Web site cites leading geoglyph scientist Alceu Ranzi. His latest discovery consists of five sets of geometric shapes, with circles, squares and lines that measures more than a mile from one extreme to another.

Ranzi explained that the geoglyphs are hard to locate from the ground; the advent of Google Earth and ready access to satellite data has greatly facilitated his task.

"You do not see them in the field. There is a difference in the color of grass, but it is very thin. If there were no satellite images, there would be no possibility [of making these new discoveries]."

For more on this discovery, read the full story on TreeHugger.com.