In California, the Sailing Stones of Death Valley have been considered the topic of a major mystery since back in the 1940’s but they may have been solved. The ground in the valley is covered with rocks, some as big as 700 pounds and have tracks that are very long behind them, almost like they were performing some sort of synchronized dance.
Even though there have been numerous theories as to how the stones were moving on their own; such as hurricane-force winds, dust devils, ice sheets or slippery algae film. None of them had ever been established as being the actual cause nor had any humans actually seen the rocks moving.
That is until now. A group of researchers from the Institution of Oceanography at the University of California at San Diego decided they were going to look into the mystery and attempt to solve it. In the winter of 2011, they transported in a high-resolution weather station to measure the wind at one second breaks and carried in 15 rocks that were equipped with special GPS devices. That was because the National Parks Service would not permit them to use any of the native stones.
However since the rocks only rarely move, only maybe about 10 years or so, they were equipped to settle down for a long time lag. However the group ended up having a stroke of luck. Research study co-authors Richard Norris and Jim Norris went back to the site in December of 2013 and found the playa was covered in three inches of water. On Dec. 21, 2013, a break of ice occurred about noon, with cracking and popping noises coming from all around the frozen pond surface, declared Richard Norris. He told Jim that they had discovered the source of the movement of the Sailing Stones.
As it so happens, the rock movement entails a perfect chain of events. First, the playa must fill with water, which has to be deep enough to allow ice to form during the winter but still thin enough that the stones are visible.
After the temperature falls at nighttime, the pond freezes into thin panes of ice, which then have to be thick enough to preserve strength, but also thin enough to travel around at liberty. When the sun emerges, the ice thaws and snaps into floating pieces. They are blown transversely over the playa by light winds, forcing the Sailing Stones in front of them.
Everything is surprisingly calm, the ice sheets are only about 0.25 of an inch thick and move under winds of 10 mph. This pushes the stones along at a haste of only a few inches per second. That is a speed which is just undetectable at a distance unless a person knows what he or she is looking for.
However for all mystery buffs, there may still be one left to be solved. Richard Norris stated that they documented five different rock movements in the nearly three months the pond existed and some involved over hundreds of stones. He added that even in Death Valley, renowned for its heat, floating ice is a potent force in rock movement but they still have not seen the very big rocks move out there. They are wondering if those move the same way.
Their research report can be read in the newest edition of the science journal PLOS One.
The Sailing Stones of Death Valley have been considered the topic of a major mystery since back in the 1940’s.
By Kimberly Ruble