Wednesday, March 17, 2010
Finally made it to Racetrack Playa - quite the ride up a small, very rocky road - four wheel drive is preferred.
Racetrack is is located in the Panamint Mountains, Death Valley National Park. What happens at Racetrack is that stones seem to mysteriously move around this very dry surface. They leave trails behind them - seems like this is a game of chess and we are not privileged with the rules.
The following is from the Wikipedia:
The sailing stones are a geological phenomenon found in the Racetrack. The stones slowly move across the surface of the playa, leaving a track as they go, without human or animal intervention. They have never been seen or filmed in motion. Racetrack stones only move once every two or three years and most tracks last for just three or four years. Stones with rough bottoms leave straight striated tracks while those with smooth bottoms wander. Stones sometimes turn over, exposing another edge to the ground and leaving a different-sized track in the stone's wake.
The sailing stones are most likely moved by strong winter winds (up to 90 mph), once it has rained enough to fill the playa with just enough water to make the clay slippery. The prevailing winds across Racetrack Playa travel blow from southwest to northeast. Most of the rock trails are parallel to this direction, lending support to this hypothesis.
An alternate hypothesis builds upon the first. As rain water accumulates, strong winds blow thin sheets of water quickly over the relatively flat surface of the playa. A layer of ice forms on the surface as night temperatures fall below freezing. Wind then drives these floating ice sheets, their aggregate inertia providing the necessary force required to move the larger stones. Rock trails are again expected to remain parallel to the SW winds.
If you are in Death valley make it a point to get up and see this location - takes a bit of time and patience but well worth the visit.