How rocks move
Racetrack Playa is home to an enduring Death Valley mystery. Littered across the surface of this dry lake, also called a “playa,” are hundreds of rocks–-some weighing as much as 700 pounds-–that seem to have been dragged across the ground, leaving synchronized trails that can stretch for hundreds of meters. What powerful force could be moving them? Researchers have investigated this question since the 1940s, but no one has seen the process in action--until now.
Provided by Scripps Institution of Oceanography