Thousands of tourists are flocking to Cusco, Peru, to see a rare geological wonder—a rainbow-colored mountain. But some scientists worry that the influx of people may damage the once-pristine landscape.
Rainbow Mountain was discovered only a few years ago. It had long been hidden under a blanket of snow. But warming temperatures linked to climate change recently caused the snow to melt. That revealed a surprise: stripes of brightly colored sedimentary rock. This type of rock forms as layers of sediment, like dirt, silt, and sand, accumulate over time, says Silvia Rosas, a geologist at Pontifical Catholic University of Peru. Different minerals found in the layers can give them distinct colors. After millions of years, movement within Earth’s crust, or outer layer, slowly pushed these layers up, creating Rainbow Mountain.
While Rosas is concerned about the uptick in visitors, she’s taking the long view: People will come and go, she says, “but the rocks will still be there.”