The Racetrack Playa in Death Valley California is home to the mysterious sliding rocks. Racetrack Playa is actually a dry lakebed within the Panamint Range of mountains. It stands at an elevation of 3711 feet. The sliding rocks range in size from small rocks to boulder size, weighing as much as 700 pounds. These rocks were originally part the cliffs from mountains which are located on one side of the lakebed.
The lakebed itself is essentially flat, so once the rocks fall from the cliffs and come to rest, it would be reasonable to assume that would remain in that location. Strangely, that is not the case. Although no human eyes have ever witnessed their movement the telltale tracks in the lakebed illustrate just where the rocks have traveled. The tracks look much like that which a heavy object would leave if it were pushed along the ground.
The grooves left by the rocks indicate the seemingly random paths of motion. The furrows vary not only in length but also in direction. While most display a prevailing south/southwest to north/northeasterly direction the paths are often not in a straight line. Many exhibit a change of direction. Some rocks have left gentle curving trails while others show a right angle directional change. Still other paths run parallel to each other. Some have traveled short distances while others have managed to move almost 3,000 feet.
So what is the force that moves the sliding rocks of Racetrack Playa? Geologists have traveled to the lakebed in search of the answer to that question for over 5o years. One theory put forth in 1955 by George M. Stanley is that the rocks slide on ice sheets which form when the lakebed is flooded. This flooding takes place once or twice a year. At times the depth of water may reach 2 inches. During the colder times of year this water will freeze. However, in 1976 Robert Sharp and Dwight Carey analyzed the tracks and performed experiments and came to the conclusion that this could not be the reason for the rocks to slide. There are other geologists who agreed with Stanley’s theory.
Wind is another popular theory. Some believe when the rain does come and the lakebed becomes muddy the wind is able to blow the rocks along leaving the paths. Others theorize that there is some magnetic force which draws the rocks. But the fact that the rocks do not move in the same pathway would make that theory unlikely.
There are those who have speculated that it is a hoax. This is not a logical explanation due to several facts. First of all reports of the sliding rocks originated over one hundred years ago and this is a remote area to access. Also with the size of some of the boulders involved there would be indications of human tampering and the equipment necessary to move such heavy objects. There has been no indication of this on the lakebed. Still others believe the area is haunted.
In July of 1996, Paula Messina and Phil Stoffer recorded the location of over 150 of the rocks and their trails in the riverbed. They were able to do this with the Global Positioning System (GPS). Their map is accurate to within .98 feet. They gave each rock a woman’s name, as had their predecessor Robert P. Sharp, and indicated the pertinent mapping information. This will provide an accurate record of rock movement which can be analyzed by geologists which may help them to come to a final conclusion about what causes the rocks to move. Until that time, it is still one of Earth’s mysteries.
Resources:
http://www.associatedcontent.com/article/493433/the_mysterious_sliding_rocks_of_death.html
http://www.physicsforums.com/archive/index.php/t-60676.html
http://geosun.sjsu.edu/paula/rtp/intro.html
http://sophia.smith.edu/~lfletche/deathvalley.html
