Discussion Topic |
|
This thread has been locked |
| Messages 1 - 18 of total 18 in this topic |
Jon Beck
Trad climber
Oceanside
|
|
|
Aug 28, 2014 - 08:55pm PT
|
Amazing it took as long as it did to figure that out, now it makes perfect sense how they moved. Racetrack Playa has always fascinated me.
|
|
StahlBro
Trad climber
San Diego, CA
|
|
|
Aug 28, 2014 - 09:00pm PT
|
GPS on the stones. Great idea. Still a crazy place.
|
|
jstan
climber
|
|
|
Aug 28, 2014 - 09:44pm PT
|
On ST several years ago I noted that the cracking in the soil indicated the area was periodically flooded. Then I said during a cold night ice able to float the rocks would be there and because heat would be coming up from the soil any firm connection to the soil would be melted. Then with a little wind you would have drag marks.
Apparently we are now ready to agree no restless spirits were needed. Holy sh#t Mabel! Who woulda thought this to be possible? In 2014! By 4800 AD yeah. But 2014? NFW.
|
|
WBraun
climber
|
|
|
Aug 28, 2014 - 09:48pm PT
|
Death Valley mystery finally solved.
Huh?????
Jstan solved it years ago.
These recent wankers are posers .....
|
|
NutAgain!
Trad climber
South Pasadena, CA
|
|
|
Aug 29, 2014 - 08:58am PT
|
Were they trying to get away from Werner humping them?
|
|
dee ee
Mountain climber
citizen of planet Earth
|
|
|
Aug 29, 2014 - 09:09am PT
|
What a cool/powerful place that is. And it is a nice breakthrough to actually see it happening.
|
|
Toker Villain
Big Wall climber
Toquerville, Utah
|
|
|
Aug 29, 2014 - 04:05pm PT
|
Any tracker worth his salt could've told 'em.
|
|
Paul Martzen
Trad climber
Fresno
|
|
|
Aug 29, 2014 - 05:15pm PT
|
I missed Jstans past explanation as I was not familiar with the rocks stuck in ice sheets concept. Makes sense. It had to be wind pushing the rocks around, but it would have to be gale force to move small but heavy rocks by themselves. Once they are frozen in a large ice sheet, the ice sheet acts as a big sail. The wind is pushing on a very big sheet of ice and not just on the small but heavy rock.
|
|
WBraun
climber
|
|
|
Aug 29, 2014 - 05:25pm PT
|
Locker -- "But then I know EVERYTHING...
Just ask me and I'll tell you..."
OK
How many lockers does it take to make a high school .....
|
|
rottingjohnny
Sport climber
mammoth lakes ca
|
|
|
Aug 29, 2014 - 06:33pm PT
|
And why does it get so hot in Death Valley...?
|
|
Dapper Dan
Trad climber
Menlo Park
|
|
|
Aug 29, 2014 - 07:36pm PT
|
I've spent some time at the racetrack playa , it's a great place...
Yea , I always thought the reason the stones moved was pretty obvious , ice sheets , melting point , winds in the right combinations ... but I guess now it is 'proved' ... cool story none the less ... a few pics from the playa , and the grandstand rocks in the middle :
|
|
ryanb
climber
Hamilton, MT
|
|
|
Aug 29, 2014 - 09:28pm PT
|
The linked article isn't very good, read the abstract on the journal site. The thing they discovered was that it wasn't thick ice sheets and strong winds but actually happened with thin ice and lighter winds which is pretty cool.
" In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, “windowpane” ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of ~4–5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2–5 m/min."
"Observed rock movement occurred on sunny, clear days, following nights of sub-freezing temperatures. Steady light winds and morning sun caused floating ice to break-up near mid day, accompanied by widespread popping sounds from fragmenting ice panels. Ice initially broke into floating panels tens of meters in size that became increasingly fragmented and separated by open rippled water as melting continued. Floating ice sheets driven by wind stress and flowing water, pushed rocks resting on the playa surface, in some cases moving >60 rocks in a single event "
|
|
neebee
Social climber
calif/texas
|
|
|
Aug 29, 2014 - 10:24pm PT
|
hey there say, all... thanks for the neat share...
|
|
Dr.Sprock
Boulder climber
I'm James Brown, Bi-atch!
|
|
|
Aug 30, 2014 - 12:31am PT
|
remember that heavy rocks will weigh much less underwater, or in this case, partially submerged,
i do not know the specific gravity of the Death Valley stones, probably less dense then say, granite, or gabro,
check out an underwater gold dredger video if you need a visual on this,
|
|
Bad Climber
climber
|
|
|
Aug 30, 2014 - 06:01am PT
|
Cool! Thanks for this.
BAd
|
|
scuffy b
climber
heading slowly NNW
|
|
These wind speeds are only around 10 mph.
I haven't seen (yet) the depth of water, only the thickness of the ice.
|
|
| Messages 1 - 18 of total 18 in this topic |
|
SuperTopo on the Web
|
Let us know!