Research: How rocks move when no one is watching

At Racetrack Playa in the Death Valley National Park, California, strange forces are at work. Forces capable of pushing heavy rocks across the flat surface of a dried-out lake while no one is looking. 

Scientists have scratched their heads over the trails left by these sliding stones since early in the 20th Century. In the 1960s, Californian geologists started a rock monitoring programme. 

They tracked 30 stones, weighing up to 25kg, 28 of which moved during a seven-year period - some more than 200m. Analysis of the stones’ trails suggested speeds of 1m per second. In most cases, the stones travelled in winter. In the decades that followed, theories about ice and wind gained support. Others involved algal slime and seismic vibrations.

So what’s happening? Are the stones sliding around in bad weather? 'We think so,' says Dr Gunther Kletetschka, of the Academy of Science of the Czech Republic and Charles University in Prague, who led a 2013 study on the stones.

Read more: http://www.dailymail.co.uk/sciencetech/article-2528351/From-Costa-Ricas-great-balls-wandering-rocks-Death-Valley-The-10-natural-phenomenon-modern-science-explain.html#ixzz2oJW0lj00