Researchers from the Scripps Institution of Oceanography and John Hopkins University discovered the secret of the sailing stones in Death Valley.
The sailing stones, or moving rocks, is a geological phenomenon which happens every two or three years in which rocks move along a valley without any human or animal touching them. This phenomenon was observed at the Racetrack Playa in Death Valley National Park in California and Little Bonnie Claire Playa in Nevada.
In an attempt to explain this mysterious phenomenon, the researchers monitored the rocks and documented their observations in video. The video shows the time-lapse of the rock's photographs, as well as their GPS locations as they moved through the Racetrack Playa.
The researchers concluded that it was thin ice, which looked like panels of broken glass that caused the rocks to move across the valley. The thin ice, along with winds, created a hydroplane effect on the rocks, enabling them to move from one place to another.
"It's a wonderful Goldilocks phenomenon. Ponds like this are vanishingly rare in Death Valley, and it may be a decade between heavy enough rain or snowfall events to make a substantial pond," study author Richard Norris told Live Science. Norris works as a paleobiologist at the Scripps Institution of Oceanography in San Diego, Calif.
The researchers further explained that there should be enough ice and water to make the rocks move for a "sailing stones" phenomenon to happen. The lake must have enough water to hold the floating ice but should be shallow enough so that the rocks can move about. The thin ice should also be tough enough to carry the rocks through big panels which might displace them. As a final requirement, freezing nights should be typically followed by the winds of summer, to facilitate the ice and the rock's movement across the lake.
Colder locations experience the same phenomena and here, the ice can move much bigger objects than rocks. As the frozen rivers thaw out when spring comes, the ice can transport big boulders of rock.
Further details of the study were published in the Aug. 28 issue of PLOS One.
Watch the video here.
