Deep in the heart of the California desert lies one of the natural world’s most puzzling mysteries: the moving rocks of Death Valley.
These are not ordinary moving rocks that tumble down mountainsides in avalanches, are carried along riverbeds by flowing water, or are tossed aside by animals.
These rocks, some as heavy as 700 pounds, are inexplicably transported across a virtually flat desert plain, leaving erratic trails in the hard mud behind them, some hundreds of yards long.
They move by some mysterious force, and in the nine decades since we have known about them, no one has ever seen them move.
Until now that is!
Racetrack Playa is the seasonally dry lake (a playa) located in the northern part of the Panamint Mountains in Death Valley National Park, California, U.S.A. that is famous for ‘sailing stones‘.
One cold winter morning, when the snowmelt covered the playa, the solution to the puzzle was finally caught on film.
That kick ass photo above is by MeLastMohican. I have no idea what his real name is, but he
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That really is a trip … it does make me a little sad, though, that I didn’t go down to Black Rock City this year for the Burning Man festival. Man dad is a geophysicist and he really enjoys the ‘racing rocks’ phenomenon because geological time is usually so slow!
Wow.. it’s odd that it washes over some rocks, completely ignoring them. I guess it’s a matter of which area of water is the most dense. Forwarding this one to a few friends :)
MG, all bodies of water and sections of those bodies of water will have the same density…I think it would depend on current or the size of the rocks, possibly how deep they are embedded?
It is also interesting to note that the crinkled surface of the mud remains relatively unchanged. I am guessing that the mud is frozen or baked hard so that the water flow doesn’t change it but a rock dragging across the surface would. Without that video, one would have to assume some hippies from Burning Mans wondered over in the night and did the rearranging.
I wonder if the clay surface of the dry lake bed contains the mineral called Kaolin? Kaolinite is a clay.It is a soft, earthy, usually white mineral (dioctahedral phyllosilicate clay), produced by the chemical weathering of aluminium silicate minerals like feldspar. In many parts of the world, it is colored pink-orange-red by iron oxide, giving it a distinct rust hue.It is widely used as a replacement for talc.It is also used as a lubricant.It is what gives glossy paper it slick shiny appearance.
If kaolinite is leeching out of the clay when it is wet or submerged with water the surface would become very slick!
I just watched the video but I never actually saw a rock moving just the water flowing.
I noticed the same thing ! It seemed easy to zoom in on stationary stones, but no inclusion of a stone suspended by the water with a close-up of how the water was actually acting on the stone. Ice would do it, I guess, but there’s a whole set of hydrodynamic issues as to the effect of Ice both on the stones and the soil. I could see Ice, maybe, but nothing in the video was definitive. RATS !
The Dunning video was incredibly irresponsible. It showed no stones moving, yet claimed to be the explanation. The real reason the stones slide is due to the common phenomenon known as frost heave. Ice lenses form beneath the surface at the freeze thaw boundary heaving the soil upward and creating a slope for the stones to slide down.
What nonsense! The real reason is the rocks are magic rocks.
Obviously! ;)
same here. also, why wouldn’t stones be dragged back as water receded.
Also look at thisSliding Rock Locations and Trail Lengths, July 1996. The video doesn’t explain why the rocks have different patterns in their movement and generally move uphill (the northern section of the playa is a few centimetres higher than the southern end)
Another short but interesting read The Racetrack Playa – Death Valley, California
water seeping upward through the ground freezes on the surface in cold times. I have previously observed these long icicles which appear to grow from the ground and carry topsoil. The frozen crystals should have sufficient power to move the rock very slightly in the upward direction. When the sun shines again, it causes the ice to melt where there is no shadow, causing the rock to sag in that direction. Upon sagging “forward” the rest of the ice will melt or alternatively the ice will grow under it again. This causes an inching effect, the reason for the paths is that the ice will generally grow everywhere, however the rock has a compaction effect of the ground it is situated on. Irregular rocks have irregular shadows and hence the differential preference in direction, direction can change depending on the time of year and the position of the sun relative to the rock, there is also the possibility of rock rotation, based on the same principle. Does anyone agree?
:-) Knowing how the trick is done doesn’t make it any less magical
What I think needs to be added to the explanation is the effect of pore pressure at the interface between the bottom of the stone and the wet mud surface. Pore pressure is a resisting upward force generated by a film of water that occurs around and between mud particles and confined by the block of rock above it. Since water is virtually incompressible, the object is able to move laterally in response to a temporary current produced by the advancing edge of the temporary lake. But the pore pressure “buoys” up the rock, and it can slide on extremely low slopes, such as that of the playa (normally an intermittently wet, surface of deposition in a dry climate environment.
It is sort of analogous to hydroplaning tires on wet pavement. The tires are not in contact with the pavement because of the film of water between the tires and the pavement. Water cannot be compressed, so any confined water in the tread builds up pore pressure, and floats the car (or the rock). Sometimes you can see a water glass with a wet bottom slide in funny directions on a table.
Try and push an irregularly shaped rock in a straight line with a broom, stick, board, car, or even your hand. Hard isn’t it!
Also, try pulling an irregularly shaped rock in a straight line by tying a string to it. Doesn’t track in a straight line does it?
Unless you have a hockey puck, a blemish-free sliding surface, and a perfectly uniform sheet of ice being blown by a perfectly straight wind, the track that is going to be left when all is said and done will not be straight.
Why exactly is it surprising that non-linear tracks are left by the irregularyl shaped rocks, which are being pushed by irregularly shaped ice, which is in turn being pushed by irregular wind? Also consider that the sheets of ice will encounter other bigger rocks or surface irregularities creating friction and pivoting of the direction of force.
Experiment: sprinkle a little sand on a frozen pond surface. Put a rock on it. Get a piece of thin plywood and cut it in a random shape. Now put that next to the rock. Stand behind the sheet of plywood. Now push it and see if you can make it track in a straight line.
Very interesting, EXCEPT- this would only result in short changes in direction, as these forces are randomly but constantly acting on the rocks, and the tracks seem to extend for long distances in fairly consistent directions. If we’re counting on wind to act with the porepressure, etc, allowing the ice to suspend the stones and the wind to act on it, we should be able to research the direction of prevailing winds and see if that helps the explanation, except that the tracks are long enough and consistent enough and happen over a long enough span of time that randomness is reintroduced into the process, which seems to work against the theory. Try the hocky puck thing and you’ll see what I mean. Which day did the prevailinfg winds shift, and did they stay from that direction long enough to sustain the track, when other nearby stones move in other seemingly unrelated directions?
Now theres a theory that makes sence. As for the rocks in proximity of others that dont move, I think you will find that the non-moving rocks are kept in place because of jaged surfaces facing down, anchoring them, where the moving rocks were likely to have a smooth surface oriented against the surface of the mud. Also if this ice sheet is the force that is pushing these rocks, mabe the jaged surfaces facing up is fractureing the ice rather than letting it push them. At any rate that would answer some of the theorys. What about the large rocks, and how big are the largest rocks with trails behind them? Any as big as say a 5 gallon bucket? or a dish-washer or a similar size? Id think the force to move such a large size would negate the ice-flow theory……..at any rate its an interesting mystery
goto Curtis Rx’s site he has a couple theory’s there even a copy of 1 of 3 books left about the rock the theory in the book is way better than this makes TUNS more sense and yes i didnt see one rock move if the rocks way from 20-700 pounds how would that water move it or even ice for that matter it couldnt its way to heavy… Curtis Rx look him up he’s from the band creature feature :D
Ok so that is a good explanation but about the fact that the water would wash away the trail?!?!? Scince it is said to be pulled by the ice and water how do the trails remain?!!?!?!?!!?!?!?!?!??!?!?!?!??!
What about that 700 pound rock? How’s a thin sheet of ice gonna move a behemoth like that?
Was reading up on it and it appears that rock, “Karen” moved about 800 meters from 1979-1996. Still seems like a mystery to me….
Erm, the solution to the puzzle was NOT caught on film. No one saw a rock move. They saw water moving…. fail
Roger ROGER !
Time and pressure can do a remarkable things . And being that the rocks have all the time in the world to move. And the world has the pressure. It’s no surprise to me. it seems that people think too deeply about the subject . in that valley i bet the winds could be in excessive of 80 miles per hour 4 days on end. and given the mud and ice factor rocks will move . look at what tornadoes can do with just with wind. try living in the windy parts of wyoming and you’ll understand . i must say it’s interesting and it gets people to thinking. but don’t try to get to scientific about it.
darin-
That’s the fun of it ! Trying to explain the inexplicable with science ! Actually, all we have here is a collection of some really interesting theories, and some interesting opinions; but that’s what makes a mystery so much fun !
Just because it is not caught on tape does not make this theory wrong. No one has seen mountains form but we know how they got here. If it is an ice sheet moving the rocks then the height of the rock in question as well as the center of gravity should be considered. My theory is: Ice is moving the rocks but the randomness in the shape of the rock and the rock along with the center of gravity can cause the rock to drag or plow in different directions. If you pushed or pulled a odd shaped rock… It would flip and flop all over the place. But make it slow like the ice sheet…. then you can get long lines and odd and unexplained direction shift. This again would be linked to the height and shape of the rock. Water freezing can produce force around 114,000psi so a rock is very easy ( no matter what size ) to move . Just my thoughts!
The photos show all GENERALLY moving it the same direction. Is it from east to west? The cause could be differential heating of one side and then the other over the course of the day. First the sun heats up the east side, and it expands a bit, shifting the stone’s CG a tiny bit to the west as it “pivots” about the base on the shady side. Things equalize at mid-day. In the late afternoon the east side cools first, allowing that side to contract a tiny bit. After dark the west side cools, shrinking it and again shifting the CG a tiny bit west. They could test this by putting a open tent over a stone but with side flaps that would keep the sunlight from striking it directly.
A similar thing happens to Donald Judd’s aluminium boxes in a Marfa, TX museum that also gets lots of sun and is situated such that the early morning and late afternoon sunlight streams in from the large windows and strikes the boxes. See:
http://en.wikipedia.org/wiki/Chinati_Foundation
Problem with much of the speculation here, they do NOT move in a single direction. Two can move together and then one turns while the other continues straight. Two can move together, then one slows down. Two can move together then one backs up. I suppose the sun changed direction on those day for one of the rocks?
Also notice the mound of clay ahead of the rocks, not pressed underneath, but out in front. These rocks moved swiftly and stopped swiftly!
I agree with Shaun but I don’t believe ice sheets come into it. The wind blows water onto the exposed side of a rock, at night the water freezes and expands. This force could easily be enough to move a very large rock; when the wind direction changes the exposed side changes and thus the direction of travel. The shape of rock is also a factor. Is this what you were proposing Shaun?
Sorry, Shawn.
My bad
This seems fake to me…some shots of tide water or something ….it could even be him with a bucket !
no rocks moved ! Come on people don’t be so easily fooled!
I moved them (was bored). Sorry for all the trouble. I’ll put them back.
this is known to be happening for almost 100 years. Isn’t there a pile of rocks at one end?
The rocks just know where they ar going
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