Death Valley’s boulders move all on their own
A HISTORY OF ROCK MOVEMENT POSTULATIONS
One researcher suggested that algal film might form on the playa, making the flat surface slick enough that a prevailing breeze could scoot the rocks along.
Some theorists thought air currents worked on their own. If ever a hurricaneforce wind swept over Southern California, it could certainly push the boulders around.
An unsubstantiated claim once held that something in Earth’s magnetic field triggered the stones’ sudden movement.
(It makes more sense than aliens, another popular hypothesis.)
One group got close: It proposed that during a storm, ice would freeze around the stones and they’d glide across the playa. But ice can’t hold that fast to individual rocks the way it can in one big sheet.