“Sailing stones” on Racetrack Playa in Death Valley have long been a mystery. Everyone who visited this place had their own theory why the rocks move on this flat and dry land.
Some thought they moved on rainy days, when the ground was slippery enough for strong winds to transport them. Others suggested that they sailed when the valley was covered in ice.
Almost all the theories suspected that strong winds were the cause of “sailing stones”, but as it came out, wind had little to do with it. A team led by Richard Norris of the Scripps Institution of Oceanography carried out a long and actually quite boring experiment involving rocks with motion-activated GPS units and some long camera lens. They sum up their discovery in this short film:
Here’s what they observed: on some winter days the playa fills with shallow water which doesn’t cover the rocks, but is deep enough to form very thin ice. When the sun comes up, the ice starts melting and breaking, at the same time pushing the stones slowly. This usually happens on sunny days with light breeze, but the movement is so slow that it’s very hard to observe.
Anyways, another scientific success! And though the sailing stones aren’t so mysterious anymore, they will continue to amaze and attract lots of visitors. Take a look at some of the most amazing shots of Racetrack Playa I’ve found.