Pictures: What Drives Death Valley's Roving Rocks?

nationalgeographic. ^ | September 8, 2010 | Christine Dell'Amore

[JoeProBono]

One of the mysterious peripatetic, or roving, rocks of Death Valley National Park in California and Nevada sits at the end of a curved track in a summer 2010 picture.

Found in the Racetrack—an aptly named dry lakebed, or playa—the moving rocks have stumped scientists since the 1940s. For instance, the rocks are thought to move as fast as a walking person, but they've never been seen in action. Previous studies have shown that gravity or earthquakes can't explain the objects' movements.

Now a student-research project led by NASA's Goddard Space Flight Center has lent support to the idea that, during wintertime, the rocks float down the playa on small "collars" of ice, which form around the stones when lake water flows down the surrounding hills and freezes on the lakebed, according to Cynthia Cheung, a principal investigator for the project. More water flows may allow the ice-collared rocks to "float."

A team of undergraduate and graduate students studied data from tiny sensors placed underneath the soil to monitor water flows. The team found that the sensors registered freezing water temperatures in March, which would provide the right conditions for ice collars to form.

Even so, the ice theory's not rock solid, Cheung noted: The harsh desert's many microclimates mean that "each rock ... may move by a different force, [and] there may not be one hypothesis that fits all the movements."

[JoeProBono]

Traveling up to 1,500 feet (458 meters), the Racetrack's moving rocks sometimes push up mounds of clay at the ends of their tracks, as seen above in a summer 2010 picture.

Sometimes the traveling rocks move in pairs (pictured in a summer 2010 photo), possibly as part of a single ice sheet, Cheung said.

Because the Racetrack is on protected federal land, the researchers are limited in their techniques, she added. For example, the rocks can't be disturbed, and the few cameras allowed to photograph the rocks over the winter have to be hidden as part of the landscape, she said.

Tagged Trail

During the summer 2010 research project, the students used thumbtacks to outline the rock trails.

The rocks occasionally tumble from the hills onto the baked plain. In other lakebeds, the rocks "would just sit there, but in this case, they don't," Chueng said

[The KG9 Kid]

Wind does this when the playa is wet and muddy from torrential rains.

[GoldenPup]

Obviously, little green guys pop up from under the surface at night and push the rocks around with their snouts. Everybody know that!!

[Slyfox]

[JPG]

Mystery solved! Bush moves them.

[IllumiNaughtyByNature]

I don't think the temperature ever gets to freezing in DV, but I cold be wrong. I've lightly followed this phenomenon for a while but it'll be interesting to see what they come up with. Nice post.

[submarinerswife]

It's water. Saw it on best History Channel program EVER- "How the Earth was Made" episode ~ Death Valley.

[IllumiNaughtyByNature]

Ah, mud and rain would better explain it then freezing temps (see above post)except that DV never average more than .42 in. of rain.

This is interesting. I wonder if this phenomenon is seasonal or all year round?

[JoeProBono]

"There have been times when the playa is flooded with standing water up to 7 cm deep and temperatures commonly drop below freezing at the Racetrack (elevation is 3,708 feet so it has cooler temperatures than the valley floor which has the lowest elevation and the highest recorded temperature in the western hemisphere) in the winter and early spring."

http://sophia.smith.edu/~lfletche/deathvalley.html

[FrankR]

This should be worth at least a $1M grant from the obamamentalism types.

They could just set up camp in Death Valley and wait for the rocks to move. Their last project of watching paint dry ended in sheer boredom, just after the government funds ran out. /sarc

[Keith in Iowa]

It’s Jedi honing their mind tricks.

Nothing more to see here.... move along...

[steve86]

Yeah, but the standing water comes from UFO RVs discharging their holding tanks.

[ErnBatavia]

Yep...I saw a TV program on this phenomenon; that clay becomes slicker than snot when wet.

[Ole Okie]

I don't think the temperature ever gets to freezing in DV

Radiation to space might cause surface temperatures to reach the freezing point.

That's the old classic heat transfer problem (a shallow pan of water sits in the desert..etc).

[JoeProBono]

"Above are the two major movements during Reid's seven year period superimposed. Note the congruence of the tracks. (Reid et al, Fig. 1, 1995)

[DouglasKC]

I’ll bet it’s hydroplaning. If you have a glass of cold liquid on your table on a hot day it will condensate liquid on the outside and the glass will seem to move on it’s own accord as it hydroplanes on the liquid. I’ll bet it’s the same thing with cold, flat rocks warming up. Maybe they only move a litle bit every day but it adds up.

[IllumiNaughtyByNature]

Nice link. It seems that the "racetrack" is a lot higher than the floor of the valley. I'll be at the link you provided. Thanks./

INBN

[teacherwoes]

"They will never suspect"

[JoeProBono]

[Larry Lucido]

Vibrations? Like those electric football games?