Pohyblivé kameny v Údolí smrti

Moving rocks in Death Valley by Gunther Kletetschka.

When the volume of water under the ice increases the rock and ice complex becomes buoyant until it separates from the surface and can be freely transported in the water medium. As the water influx slows down and playa’s water drains, the rock and ice complex makes contact with the muddy surface and starts plowing a new narrow trail. With more water draining the rock and ice complex plows deeper and wider while thrusting a pile of mud in front, until it stops at the final location. Ice melts completely leaving little sign of the carrier.