Saturday, August 30, 2008

Sailing the Racetrack Playa of Death Valley, California


No, this isn’t another travel post… It’s rocks doing the “sailing” this time.

These are moving rocks, also known as sailing stones, that mysteriously move across the surface of the Racetrack Playa, a seasonally dry lake (or playa) in the Panamint Mountains, Death Valley National Park. Most of the racetrack rocks originate from the nearby hillside of dark dolomite on the south end of the playa. As they move without human intervention, the rocks leave long tracks behind them, often tens of hundreds of feet and typically less than an inch deep. The rocks move once every two or three years and most tracks last for just three or four years. Rocks with rough bottoms leave straight striated tracks while those with smooth bottoms wander.

During periods of heavy rain, water washes down from the nearby mountain slopes onto the playa and form a shallow short-lived lake. Soon, the thin veneer of water evaporates and leaves behind a layer of soft gooey slippery mud. As it dries the mud shrinks and cracks into a mosaic of interlocking polygons.


Geologists have long speculated on the explanations of this very cool phenomenon. Most favor the idea that strong winds (nearing 90 mph) push the rocks along the playa’s muddy bottom left at the end of the rainy period. However, some of the stones are thought to be too heavy (weighing as much as a human) for the area’s wind to move. Some geologists maintain that ice sheets around the stones may help to catch the wind or move in ice flows. But both theories don’t explain how two rocks right next to one another can move in opposite directions or one can stay put while another three times its size doesn’t.

Ahh… the mysteries of Nature. I guess you can’t judge a rock by its mantle.




Nina Munteanu is an ecologist and internationally published author of novels, short stories and essays. She coaches writers and teaches writing at George Brown College and the University of Toronto. For more about Nina’s coaching & workshops visit www.ninamunteanu.me. Visit www.ninamunteanu.ca for more about her writing.


8 comments:

Janet said...

I had never heard of these. It's really mind-bending how many things we can't explain.

sfgirl said...

I hadn't heard of them either, and I traveled right through Death Valley a few years ago. Missed it! Shucks. I'll just have to find my way down there again. It's actually quite wonderful to knkow that Nature remains full of mysteries. This is why I both love to travel the world and am fascinated by the study of Nature... ... Sailing stones... What's next? Singing sands? In fact, yes!

yrider said...

Yes it is true. You have to see it to believe it. I can understand why a rock would roll in one direction, but to move sideways and a different way then a rock that is right next to it is remarkable.

sfgirl said...

I take it you've been there, Yrider. Cool!... Yes, it is rather remarkable and just like Nature to constantly baffle us, by seemingly providing us with "rules of Nature" then breaking them.

Jean-Luc Picard said...

Death Valley isn't exactly the place to feel the cool breeze, Nina. Thanks for this view of nature

sfgirl said...

LOL! No, it isn't, is it, Jean-luc! More like a hot breeze! And not what you think of when the word "sailing" is mentioned... The whole scenario is an oxymoron: sailing stones in a hot breeze in Death Valley... HAR! Nature is so wonderful!

Footsteps said...

Hi Nina,
(Found a flash fix!) Really interesting post; you explain the geological very well (no surprise!).
Looking forward to scrolling back and checking what I've missed...

sfgirl said...

Hurrah! Glad to have you back, Heather. As an avid traveler and hiker, I know you appreciate the geological: nature at her weirdest, sometimes... :) Have fun with the previous posts!
All the best,
Nina