Have you ever heard about a rock moving on its own?
Sounds impossible, right?
Well, not in Death Valley. Miracles happen in this hottest, driest, and lowest place on Earth. In the Racetrack Playa remote area, you can observe long trails left by rocks on the dry, cracked mud. People call these sailing stones.
And the mystery behind them puzzled scientists and visitors for decades.
What makes them move?
Wind, ice, magnets, or maybe aliens?
Let us explore answers to these questions and find out why these rocks are so interesting in this article.
Table of Contents
The sailing stones phenomenon
Racetrack Playa is a dry lake bed in Death Valley National Park. The playa is about 3 miles long and 1.5 miles wide and surrounded by mountains. Usually, the playa is dry, but sometimes it gets a little wet after it rains or snows. The water dries up quickly, leaving a mud layer that later breaks into polygon shapes. There are many different rocks in this mud. Some of them are very heavy, about 700 pounds. These rocks are made of dolomite and syenite.
Who brought these rocks down to the playa? These rocks just roll down from the surrounding mountains because of erosion. The upper Neogene stratigraphy and tectonics of Death Valley research paper focuses on the geological history of Death Valley.
The special thing about these rocks is they can move across the playa. You can see these rock’s long and curvy tracks from miles away. So, they’ve moved a long way from their original location. Some tracks are straight, some are zigzag, some are side by side, and some cross each other. Some rocks move faster than others, some change their path, and some even return the way they came. How awesome is that? And another special thing is that these tracks can stick around for years before they disappear or get covered by new ones.
People first noticed the sailing stones in the early 1900s. As you do, they also started guessing what could make them slide on dry land. It’s impossible, right?
They considered different reasons, like wind, ice, magnetic fields, or even aliens.
Early theories
People came up with many theories to explain why these rocks move. One theory was that a local, unknown magnetic force was causing it. However, this theory was rejected because many of the rocks don’t have a lot of magnetic materials like iron. Also, if it was a magnetic force, the rocks should all move to one place, but they don’t.
Another popular theory was that the strong winds in Death Valley were moving the rocks. But this theory also had problems. Like, the rocks didn’t all move at the same time or in the same direction. And some of the rocks were just too heavy to be pushed by wind.
The breakthrough study
The mystery of the sailing stones remained unsolved until 2014. That’s when the research team led by Richard D. Norris and James M. Norris found the answer and published it. Their research reported the first documented observation of the sailing stones actually moving. Read more
They used new technology and methods to study the rocks for four years. How? They put a weather station near Racetrack Playa to watch the temperature, wind speed, rainfall, and humidity. They also put GPS on 15 rocks on the playa to track them. They also used time-lapse cameras to take pictures of the playa every few seconds.
All their hard work paid off when they saw something nobody had seen before: the sailing stones moving. Twice, in December 2013 and January 2014, they saw rocks moving across the playa at 2 to 6 inches per second speeds. They also found out how it happened. It was a special combination of ice, water, and wind.
The mystery behind the role of ice and wind solved!
This is what happens, according to the study. First, rain or snow fills Racetrack Playa and creates a shallow pool of water. It covers most of the surface. Terrain analysis of the Racetrack Basin and the sliding rocks of Death Valley paper focuses on the geological features of the Racetrack Playa, specifically the playa’s surface and surrounding topography. Read more
Then, when night comes, the temperature drops below freezing and a thin layer of ice forms on the water. The next day, the ice melts and breaks into big floating panels when the sun shines. Racetrack Playa, Death Valley, USA paper explores the role of temperature and water levels in the movement of sailing stones.
These panels get pushed by gentle winds across the playa. As they move, they meet rocks on the bottom of the playa or partly in water or mud. The ice panels then push the rocks gently but steadily and nudge them forward. Trail formation by ice-shoved “sailing stones” paper proposes the “ice-shoving” theory for the movement of sailing stones.
Now, the rocks move and leave trails on the soft mud. Wind speed and direction affect their movement. Some stones move from 2 to 6 meters per minute or about 6.6 to 19.7 feet per minute.
Remember, these conditions are rare and only happen for a few days or weeks every few years.
Why are sailing stones fascinating?
Sailing stones are captivating because they make us question what we know about nature. They go against gravity and logic and move without any obvious force. The beautiful patterns they make on the playa look like abstract art or messages from aliens.
Sailing stones are also interesting because they are rare and hard to see. They only move once every few years when all the conditions are right. Even then, they move very slowly and quietly, and you could easily miss them if you blink or look away.
Conclusion
The sailing stones of Death Valley are one of the most fascinating natural wonders that you can see on Earth. They sparked curiosity among the scientists and visitors for over a hundred years. They also made us rethink how rocks can move without any help from humans or animals. Thanks to the group of researchers led by Richard D. Norris and James M. Norris, we now have a possible answer to this mystery. Ice, water, and wind work together to move the rocks across the playa. That’s the secret behind Sailing Stone’s long and curvy tracks.