What causes the rocks to move?
The mystery of Death Valley National Park is the sliding rocks at Racetrack Playa (a playa is a dry lake bed). These rocks can be found on the floor of the playa with long trails behind them. Somehow these rocks slide across the playa, cutting a furrow in the sediment as they move. Scientists have theorized shifts in Earth’s gravitational pull, gale-force winds, slippery algae, aliens, and even late night pranksters as the reason behind the sailing stones. Gravity pulls downward, so the idea of the moving rocks being pulled uphill defies logic, especially with the algae theory. Gale-force winds wouldn’t leave such a clear trail of drag marks, most likely spraying sand beyond them if anything. The last two were most likely, if impractical. The reason behind the Death Valley moving rocks was stranger than we’d thought as revealed in a series of photos taken with time-lapse photography via custom GPS devices. Read more at http://www.inquisitr.com/1438248/death-valley-moving-rocks-sailing-stones/#GIa2WH0sZpr22A4e.99 h\
What causes the rocks to move?
ttp://www.inquisitr.com/1438248/death-valley-moving-rocks-sailing-stones/
Racetrack playa is lake bed that is almost perfectly flat and almost always dry. It is about (4 kilometers long ( 2.5 miles - north to south) and about 2 kilometers wide (1.25 miles - east to west).
It is located above the northwestern side of Death Valley, in Death Valley National Park, Inyo County, California, U.S..
The surface is covered with mudcracks and the sediment is made up mainly of silt and clay.The surface is covered with mudcracks and the sediment is made up mainly of silt and clay. The mystery of Death Valley's sliding rocks, solved. By A.J. McCarthy While the mysterious tracks carved into the dry lake bed of Racetrack Playa in Death Valley were long ago attributed to sliding rocks, an explanation for what causes the "sailing stones" to move—thereby leaving their famous trails in the dirt—has remained elusive to researchers for some time. But, according to a study published in the journal PLoS ONE, the mystery is no more. The culprit is neither powerful dust devils, nor hurricane-force winds—it's something far more subtle: the combination of thin layers of ice and wind. By inserting GPS tags into rocks, researchers were able to monitor their movements, and then, after comparing those results with information gathered at their weather station, finally pin down exactly what was happening. Basically: When the conditions are just right, ice gathers behind the rocks, and the friction that creates—when combined with a light breeze—causes the rocks to move. For this to happen, several events must occur in tandem (which helps explain why years, and sometimes decades, separate suspected movements). Temperatures need to fluctuate at the right levels, the ice can't be too thick, and, most important, there needs to water in the playa. Considering that the lake bed is dry 99 percent of the time and the area receives less than 2 inches of annual rainfall, the team's ultimate conclusion is a fitting answer to the long-enigmatic phenomenon. “The process of ice breaking up and shoving rocks around happens every year if you go up into Saskatchewan or Ontario, but you don’t normally associate it with a hot, dry place like Death Valley,” said paleoceanographer Richard Norris, one of the main researchers behind the study. “And yet here’s the same kind of process unfolding occasionally—very occasionally—in this place that we associate with a very different kind of climate.” Watch the video above for a more thorough explanation of the science behind the sliding rocks, and how, exactly, Norris and his team were finally able to put the mystery to bed. A.J. McCarthy is a Slate video blogger.
source: http://www.slate.com/articles/video/video/2014/08/death_valley_sliding_rocks_researchers_discover_what_causes_the_mysterious.html
All rights reserved to the Video Blogger and source's writer/reporter
The mystery of Death Valley National Park is the sliding rocks at Racetrack Playa (a playa is a dry lake bed). These rocks can be found on the floor of the playa with long trails behind them. Somehow these rocks slide across the playa, cutting a furrow in the sediment as they move. Scientists have theorized shifts in Earth’s gravitational pull, gale-force winds, slippery algae, aliens, and even late night pranksters as the reason behind the sailing stones. Gravity pulls downward, so the idea of the moving rocks being pulled uphill defies logic, especially with the algae theory. Gale-force winds wouldn’t leave such a clear trail of drag marks, most likely spraying sand beyond them if anything. The last two were most likely, if impractical. The reason behind the Death Valley moving rocks was stranger than we’d thought as revealed in a series of photos taken with time-lapse photography via custom GPS devices. Read more at http://www.inquisitr.com/1438248/death-valley-moving-rocks-sailing-stones/#GIa2WH0sZpr22A4e.99 h\
What causes the rocks to move?
ttp://www.inquisitr.com/1438248/death-valley-moving-rocks-sailing-stones/
Racetrack playa is lake bed that is almost perfectly flat and almost always dry. It is about (4 kilometers long ( 2.5 miles - north to south) and about 2 kilometers wide (1.25 miles - east to west).
It is located above the northwestern side of Death Valley, in Death Valley National Park, Inyo County, California, U.S..
The surface is covered with mudcracks and the sediment is made up mainly of silt and clay.The surface is covered with mudcracks and the sediment is made up mainly of silt and clay. The mystery of Death Valley's sliding rocks, solved. By A.J. McCarthy While the mysterious tracks carved into the dry lake bed of Racetrack Playa in Death Valley were long ago attributed to sliding rocks, an explanation for what causes the "sailing stones" to move—thereby leaving their famous trails in the dirt—has remained elusive to researchers for some time. But, according to a study published in the journal PLoS ONE, the mystery is no more. The culprit is neither powerful dust devils, nor hurricane-force winds—it's something far more subtle: the combination of thin layers of ice and wind. By inserting GPS tags into rocks, researchers were able to monitor their movements, and then, after comparing those results with information gathered at their weather station, finally pin down exactly what was happening. Basically: When the conditions are just right, ice gathers behind the rocks, and the friction that creates—when combined with a light breeze—causes the rocks to move. For this to happen, several events must occur in tandem (which helps explain why years, and sometimes decades, separate suspected movements). Temperatures need to fluctuate at the right levels, the ice can't be too thick, and, most important, there needs to water in the playa. Considering that the lake bed is dry 99 percent of the time and the area receives less than 2 inches of annual rainfall, the team's ultimate conclusion is a fitting answer to the long-enigmatic phenomenon. “The process of ice breaking up and shoving rocks around happens every year if you go up into Saskatchewan or Ontario, but you don’t normally associate it with a hot, dry place like Death Valley,” said paleoceanographer Richard Norris, one of the main researchers behind the study. “And yet here’s the same kind of process unfolding occasionally—very occasionally—in this place that we associate with a very different kind of climate.” Watch the video above for a more thorough explanation of the science behind the sliding rocks, and how, exactly, Norris and his team were finally able to put the mystery to bed. A.J. McCarthy is a Slate video blogger.
source: http://www.slate.com/articles/video/video/2014/08/death_valley_sliding_rocks_researchers_discover_what_causes_the_mysterious.html
All rights reserved to the Video Blogger and source's writer/reporter
