Moving Rocks in Death Valley
Written by Nadia Podrabinek
The moving rocks or sailing stones at Racetrack Playa in Death Valley National Park, California, are a geological phenomenon where rocks move on their own and leave trails on the valley floor. First reported in the 1900s, the actual movement of these rocks wasn’t observed until 2014.
How do they move?
TL;DR Sailing rocks move due to both strong winds and the formation of thick ice. This combination reduces friction and allows even light winds to move the rocks across the area.
The rocks move only under specific conditions. These conditions typically involve the Playa filling with water which freezes during cold winter nights and then melts during the day. The melting forms large floating ice panels that light winds push across the Playa, moving rocks in front of them. However, this doesn’t happen every year and depends on precise weather conditions.
The mystery of the moving rocks in Racetrack Playa, Death Valley, has been closely linked to advancements in technology. In 2009, the use of inexpensive time-lapse digital cameras helped capture rare meteorological phenomena, including the movement of the rocks, which was thought to happen roughly every three years and last about ten seconds. However, this required sorting through a massive amount of footage as the rocks’ movement is very infrequent.
One prevailing theory suggested that small ice rafts form around the rocks, allowing them to float slightly off the soft bed and reduce friction. This makes it possible for even light winds to move the rocks if the ice is thick enough.
This “ice raft” theory was supported by evidence like narrowing trails, intermittent springs, and trail ends without rocks. Further research indicated that water draining from higher ground into the Playa and ice covering the intermittent lake buoyantly lifts the rocks in the ice floes, reducing the friction enough for wind to move them.
In 2020, NASA dismissed the idea that microbial mats or wind-generated water waves were responsible for the stones’ movement, based on fossil evidence from dinosaur footprints. This leaves the ice raft theory as one of the most accepted explanations for this natural phenomenon.
If you are visiting Racetrack Playa, it is prohibited from driving or walking outside of established routes and you are not allowed to touch or move the stones.
Hello, my name is Nadia.
I usually write about traveling (there are so many places to fit all the lifestyles), relocation (finding a job overseas or moving without losing an income), and living in a foreign country (adapting to a different culture and mentality). Follow me on Twitter, Facebook, Instagram, or LinkedIn!