Mystery of the ‘sailing stones' of Racetrack Playa: how San Diego scientists solved the enigma

Yahoo

16-06-2025

SAN DIEGO (FOX 5/KUSI) — For decades, the enigmatic 'sailing stones' of Racetrack Playa in Death Valley National Park have captivated scientists and visitors alike. There are large rocks, some weighing up to 700 pounds, that leave behind long, winding trails across the dry lakebed.
This phenomenon led to various theories about their movement—from alien interference to magnetic anomalies. However, a groundbreaking study led by researchers from the Scripps Institution of Oceanography at UC San Diego eventually uncovered the natural forces behind this geological mystery.
In 2014, a team of scientists, including paleobiologist Richard Norris, his cousin James Norris and planetary scientist Ralph Lorenz, set up an ambitious experiment to observe the movement of these stones firsthand. They equipped 15 rocks with GPS trackers and established a high-resolution weather station at the southern end of Racetrack Playa. Their goal, according to the researchers, was to capture the rare conditions under which the stones move.
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At last, a breakthrough occurred. After a series of wet winter storms, the playa was covered with a thin later of water, which froze overnight into a delicate sheet of ice. The following day, light winds caused the ice to break into large panels, which, driven by wind, moved the rocks across the playa. The GPS devices recorded the movement of the rocks, confirming that the ice sheets were indeed propelling them across the surface of the desert floor.
This phenomenon, known as 'ice shove,' is common in polar regions, according to scientists, but had never been observed in such a desert environment before. This study revealed that the combination of water, ice and wind creates ideal conditions for the stones to move. The ice forms a thin, floating layer that, when broken up by winds, pushes the rocks across the soft, muddy surface, leaving behind their trails in the desert.
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The finding of their study have been published in the journal PLOS ONE. It provides a scientific explanation for the marvel that had puzzled researchers and desert dwellers alike for over a century — and it's all thanks to those San Diego-based researchers.
For those who wish to check out the 'sailing stones' in person, head to Death Valley National Park. Officials with the National Park Foundation have directed visitors to drive two miles south of the Grandstand parking area to the find the stones.
'While the precise location of the 'sailing stones' is always changing, you can usually get the best view by walking about a half-mile toward the southeast corner of the playa,' the park officials explained.
While the scientific community has unraveled the mystery, the allure of these moving rocks continues to inspire wonder and curiosity.
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