Decode the mystery of the 'walking rocks' in Death Valley

For decades, the mystery of "walking stones" has left many scientists wondering for answers. Rocks weighing up to 300kg move across a dry lake bed in Death Valley, California without any clear explanation

Death Valley - Death Valley is located near the border of California and Nevada, located in the lowest, driest and hottest place in North America. This land stretches over 136.2km and has an area of ​​7,800km2, located at a depth of 86m below sea level. There is a Racetrack Playa dry lake and large and small rocks (some weighing up to 320kg). The special thing is that they have the ability to move on their own and leave behind long trails on the cracked ground.

Until now, no one has had the opportunity to film or see the rocks moving directly on Racetrack Lake. This adds to their mystery and people believe that this phenomenon is created by the hands of supernatural powers.

There are many theories that the rocks can move on their own thanks to tornadoes, hurricanes or slippery patches of algae, but no one has ever witnessed this self-moving scene. The only thing everyone could see was the misalignment and the long slides on the dry ground.

According to observations, although they have similar shapes and masses, the rocks all have their own routes, some turn left, some turn right, follow a wavy pattern, and slide for different lengths and short distances. There are even blocks of stone that have "traveled" a distance of up to 450 m compared to the original, and it took 2-5 years to move.

For decades, all attempts to explain the phenomenon of "walking" stones have failed.

Between December 4 and 20, 2013, the researchers' cameras recorded the movements of the stones in timelapse. In the minute-long video, the stones "slide" between 3 and 5 meters. Some tracking boulders moved up to 224 meters between December 2013 and January 2014.

The researchers concluded that the phenomenon depends on rain, wind and low temperatures. The rocks move when a layer of ice 3 to 6 mm thick breaks up with winds not exceeding 5 m/s. If it were thicker, ice would not float on liquid water. When moved by the wind, they push different rocks at speeds ranging from 2 to 5 m/s.

Therefore, the trajectory of the rocks is determined by the direction and speed of the wind, in addition to the presence of liquid water below the thin layer of ice. It is worth remembering that the phenomenon occurred in one of the hottest places on the planet, so the combination of these factors is very rare.

"How do these rocks move" is always a question that many people, from tourists to scientists, have asked. More than a century later, there is still no accurate answer.

Scientists can only come up with many hypotheses to explain this phenomenon of self-walking rocks. One of the most widely believed explanations is that the stone moves thanks to gravity.

However, this hypothesis was later rejected when scientists carefully studied the terrain of this area. This is a flat area, the south is not significantly lower than the north, only a few centimeters. So, in theory, the stones will be very difficult to move. Yet they still mysteriously travel long distances.

Besides, there is a theory that the stone moves because of the wind. The wind here is very strong and pushes the rocks away. Some people have asked to attach tracking devices to the rocks to record its movement.

Everything gradually became clearer at the end of 2013. Two researchers Jim and Richard Norris went to survey the lake bed area in Death Valley. They discovered that the movement of rocks requires the coordination of many different conditions.

First, the valley surface must be covered with a layer of water of sufficient depth to form floating ice. When the temperature drops, the lake will close with a thin layer of ice, with water remaining underneath. The amount of ice will then thicken to become hard enough to create force to push the rock. When the temperature rises, sunlight will cause the ice to crack into pieces. These ice floes will be pushed away by the winds, pushing the rocks along.

However, researchers have only observed these phenomena in a few rocks, as for large rocks, they still need to study more to find out its movement.

In 1849, a group of people panning for gold, trying to find a shortcut, accidentally fell into this valley. They were disoriented, went through another period of hunger, were scorched by the sun, and were attacked by insects, snakes, and scorpions. Many people buried their bodies in this harsh place. By January 1850, only one member of the group was able to escape.

In 1941, an American investigation team lost direction also lost here and no one returned.

In 1949, another expedition entered the valley. A few people escaped this place, but then died inexplicably. Therefore, this valley is called Death Valley.

Although the conditions in the valley are harsh, the scenery around it is the opposite. West of the valley lies the foothills of the Nevada Range. The adjacent area has many vertical and horizontal ravines and stone pillars. Under the sunlight, the scenery is described as brilliantly beautiful. Therefore, this place attracts many tourists to visit. In 1933, the United States turned this place into a national park, and it is always crowded with tourists coming to spend the winter.