Thursday 17 December 2015

Mystery Of The Moving ‘Sailing Stones’



If you look at the picture below, you will see rocks with trails behind them. How do you think they moved?

Photo source: http://whenonearth.net/sailing-stones-death-valley/


These rocks which are commonly known as ‘Sailing Stones”, appear to have been mysterious dragged across the ground or rather appear like they have moved by themselves. What puzzles more was that some of the rocks are really heavy, reaching around 320kg.

Photo source: https://www.flickr.com/photos/ruggybear/6875285966/

They are located at dried lake in deserts but the most famous location is the Rock Playa Racetrack, Death Valley in the U.S.A. Throughout the time since research start in the 1940s, some suggested culprits were hurricane-forced wind, dust devil, aliens and magnetic field. 
No one, however, has ever seen the rocks moved – until recently. But, what do you think?


Mystery solved
At first, NASA scientist Ralph Lorenz put forward his hypothesis in 2006. However, only in 2013 that it was proven via GPS and time lapse video from cameras attached to a number of rocks. The scientists involved in the project revealed these findings in the Aug. 2014, issue #27 of the journal PLOS One.

What needed is a right combination or rather rare combination of temperature, wind, water and ice.

1. First, the dried lake must be filled with certain level of water. However, it needs to be shallow enough to expose the rock but deep enough to form floating ice sheet

2. As the night falls during the winter, the temperature drops to certain level to form ice layer. However, it must be thin enough to move freely but thick enough to maintain strength to move the rocks.

3. Next, the ice sheet cracks into huge floating panels. This happens as the temperature increases the next sunny day.

4. The last thing required is light wind to blow the ice panels across the lake. These huge ice panels then pushed the rocks in front of them with the help of slippery muddy base below. This action will leave trails in it.


The video below can also explains the phenomenon above;




Interestingly, Richard Norris, one of the scientist involved in the experiment mentioned that one of the most surprising aspect of the movements was that the thickness of the ice sheet was merely 2mm to 4mm only.
After decades of creating wonder, one world mystery is now solved. The moving rocks or more commonly known as ‘sailing stones’ can be explained by science. In other words, the right dose of temperature, wind, water and ice.


References:
1. https://scripps.ucsd.edu/news/mystery-solved-sailing-stones-death-valley-seen-action-first-time
2. http://www.sci-news.com/physics/science-death-valley-sailing-stones-02148.html
3. http://whenonearth.net/sailing-stones-death-valley/




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Shared by Fizz Tahir
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