Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all!
If I might make a guess here The area is covered under a thin layer of water, not enough to cover the rocks. Then the temperature drops, forming a thin layer of ice, trapping the rocks. Then it doesn't need a lot of wind to drag along an ice sheet with frosen in rocks. As the rocks is still protruding from the ice, it forms tracks in the underlying surface. If more than one rock is trapped in the ice, then they will form parallel tracks, turning at the same time if the wind direction shifts. I've seen the tremendous force a loose ice sheet and a modest wind can achieve. Many years ago in spring I was at our cabin near a lake. The weather had been warm and calm so the ice sheet of the lake (3 km x 1 km big) was thawed a couple of meters around the edges. Then it started to blow straight towards us and the ice started to move. First slowly, hardly noticeable, then it started to creep up onto the beach. When it started I stood at the edge of the water but after fifteen minutes I had been pushed over a meter back by the ice and along the beach was a half meter wall of ice. Then it all stopped and I've never experienced it again, but I've seen the wall of ice deposited along beaches a couple of times since then. /Göran Stuart McDaniel wrote: Would you please explain what is meant by ice-rafting in laymen's terms?? Stuart McDaniel Lawndale, NC Secr., Cleve. Co. Astronomical Society -Original Message- From: Rob Matson Sent: Saturday, February 19, 2011 3:06 PM To: Michael Groetz ; Meteorite List Subject: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! Hi Michael, IMHO, it's definitely ice-rafting. It happens on any desert playa that is hard enough, receives sufficient winter rains, and gets cold enough to freeze at night. In California, I've seen the rock furrows at Silver Dry Lake, Superior Dry Lake, Cuddeback Dry Lake and (most recently) Coyote Dry Lake. I've also seen them on some Nevada playas as well as the Alvord Desert in Oregon, and they occur in Arizona, as well. SoCal got a lot of rain this past December -- so much so that even after three weeks of dry weather in January the northern third of Coyote was under water. I've never seen this in the decade I've been going there, and sure enough I saw rock trails there for the first time last month. Bob Verish, Nick Gessler and I coauthored an abstract and presentation on this subject, and in particular its implications for meteorite recovery, at the 65th Annual Meeting of the Meteoritical Society in 2002: http://adsabs.harvard.edu/full/2002M%26PSA..37Q..51G Cheers, Rob -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com]On Behalf Of Michael Groetz Sent: Friday, February 18, 2011 5:24 PM To: Meteorite List Subject: [meteorite-list] OT (Sorta...) Why Are Death Valley's Rocks MovingThemselves? Interesting photo- wish I could crawl out of my chair in Ohio and go check those rocks out. I know this has been discussed on the list before. Have a good night. Mike http://www.foxnews.com/scitech/2011/02/18/death-valleys-rocks-moving-racetra ck-playa/ Why Are Death Valley's Rocks Moving Themselves? By Philip Schewe Published February 18, 2011 | Inside Science News Service Death Valley National Park contains many mysteries, including one of nature's strangest phenomena: rocks that seem to move around all on their own. In the remote, almost totally dry lakebed called Racetrack Playa, some of the rocks move themselves across the desert floor when people aren't watching. Scientists know the rocks move because they leave narrow tracks trailing behind them, but they haven't actually seen it happen. And although one can't entirely rule out the possibility of some prank being played, at least some of the rocks appear to be moving under natural circumstances. It doesn't rain often in Racetrack Playa, and when it does the lakebed can flood. The rocks don't float exactly, but the main explanation for their movement is that moisture can make the mud on which the rocks sit more slick, making it easier for high winds to push the rocks along. Another explanation offered is that the temporary deposit of water, chilled to form extensive sheets of ice, might help to reflect and focus the winds, making it easier for the rocks to move. The winds required to move rocks in this way would seem to be at the level of 100 mph or more. That's why the rocks are sometimes referred to as sailing stones. They are rare but they have been noticed in Racetrack Playa and a few other arid places around the world subject to occasional floods Ralph Lorenz, a scientist at Johns Hopkins University, offers a new explanation. The rocks are actually lifted up by the ice, or at least made more buoyant by the ice, making it easier for the rocks to migrate. If the rocks are moving about on ice rafts, the ground below cannot offer
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all!
Hi there, haven't followed the whole thread, therefore sorry if it's a double post, here is an article about moving rocks on Planet Mars: http://www.ucalgary.ca/news/utoday/jan7-09/martianrock Best! Martin PS: Currently camping next to a promising rock, looking like a meteorite, in desert, waiting for it to trespass an imaginary line, from where on it will immediately lose its status as a natural heritage and its cultural properties. I have no incentive to announce it to the authorities, although it looks like ALH 84001, but has fresher fusion crust, because they will declare it to be property of the state. And they even won't give me back the dime for the phone call. Anyway, it would cause only troubles. So I wait... come to papa... and if it doesn't come... who cares. It's a strange thing, with that heritage and culture and the national importance. I'm born in the country, where Ernst Florens once invented the meteorites at all. 72 entries we have in the Bulletin, quite the same like Argentina or Canada, much more than Slovakia or Denmark. And seen surface and time, we even left Australia behind. In the neighbor state, Schreibers invented modern meteoritics. We both have no meteorite law!!! Eeek! How can this be possible - a true scandal!! (I know, I know an useless argument. In Australia, Oman, Argentina..nobody knows, who Ernst Florens and Carl von was.) -Ursprüngliche Nachricht- Von: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] Im Auftrag von Göran Axelsson Gesendet: Sonntag, 20. Februar 2011 13:35 An: Meteorite List Betreff: Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! If I might make a guess here The area is covered under a thin layer of water, not enough to cover the rocks. Then the temperature drops, forming a thin layer of ice, trapping the rocks. Then it doesn't need a lot of wind to drag along an ice sheet with frosen in rocks. As the rocks is still protruding from the ice, it forms tracks in the underlying surface. If more than one rock is trapped in the ice, then they will form parallel tracks, turning at the same time if the wind direction shifts. I've seen the tremendous force a loose ice sheet and a modest wind can achieve. Many years ago in spring I was at our cabin near a lake. The weather had been warm and calm so the ice sheet of the lake (3 km x 1 km big) was thawed a couple of meters around the edges. Then it started to blow straight towards us and the ice started to move. First slowly, hardly noticeable, then it started to creep up onto the beach. When it started I stood at the edge of the water but after fifteen minutes I had been pushed over a meter back by the ice and along the beach was a half meter wall of ice. Then it all stopped and I've never experienced it again, but I've seen the wall of ice deposited along beaches a couple of times since then. /Göran __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all!
Martin, Thank you for that. It is interesting but, I don't think wet conditions in lakebeds ( which seem obvious due to the checked pattern in the dried mud ) would apply the same as dry sand blowing. This brings to mind the question; why do we need co-ords of finds again? Now we know. We can estimate how far they have traveled based on their Earth age, soil, wind and rain conditions, etc. But how do we know all that? Too many questions. Never mind. Carl -- Carl or Debbie Esparza Meteoritemax Martin Altmann altm...@meteorite-martin.de wrote: Hi there, haven't followed the whole thread, therefore sorry if it's a double post, here is an article about moving rocks on Planet Mars: http://www.ucalgary.ca/news/utoday/jan7-09/martianrock Best! Martin PS: Currently camping next to a promising rock, looking like a meteorite, in desert, waiting for it to trespass an imaginary line, from where on it will immediately lose its status as a natural heritage and its cultural properties. I have no incentive to announce it to the authorities, although it looks like ALH 84001, but has fresher fusion crust, because they will declare it to be property of the state. And they even won't give me back the dime for the phone call. Anyway, it would cause only troubles. So I wait... come to papa... and if it doesn't come... who cares. It's a strange thing, with that heritage and culture and the national importance. I'm born in the country, where Ernst Florens once invented the meteorites at all. 72 entries we have in the Bulletin, quite the same like Argentina or Canada, much more than Slovakia or Denmark. And seen surface and time, we even left Australia behind. In the neighbor state, Schreibers invented modern meteoritics. We both have no meteorite law!!! Eeek! How can this be possible - a true scandal!! (I know, I know an useless argument. In Australia, Oman, Argentina..nobody knows, who Ernst Florens and Carl von was.) -Ursprüngliche Nachricht- Von: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] Im Auftrag von Göran Axelsson Gesendet: Sonntag, 20. Februar 2011 13:35 An: Meteorite List Betreff: Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! If I might make a guess here The area is covered under a thin layer of water, not enough to cover the rocks. Then the temperature drops, forming a thin layer of ice, trapping the rocks. Then it doesn't need a lot of wind to drag along an ice sheet with frosen in rocks. As the rocks is still protruding from the ice, it forms tracks in the underlying surface. If more than one rock is trapped in the ice, then they will form parallel tracks, turning at the same time if the wind direction shifts. I've seen the tremendous force a loose ice sheet and a modest wind can achieve. Many years ago in spring I was at our cabin near a lake. The weather had been warm and calm so the ice sheet of the lake (3 km x 1 km big) was thawed a couple of meters around the edges. Then it started to blow straight towards us and the ice started to move. First slowly, hardly noticeable, then it started to creep up onto the beach. When it started I stood at the edge of the water but after fifteen minutes I had been pushed over a meter back by the ice and along the beach was a half meter wall of ice. Then it all stopped and I've never experienced it again, but I've seen the wall of ice deposited along beaches a couple of times since then. /Göran __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all!
Ice rafting is the wind or water currents moving a sheet of ice like a raft. When the ice raft hits shore it breaks up and makes piles some that can be very deep. Cheers Steve Dunklee __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all!
So you saying these rocks are blown by the wind as they are floating on a sheet of ice? Stuart McDaniel Lawndale, NC Secr., Cleve. Co. Astronomical Society -Original Message- From: Steve Dunklee Sent: Sunday, February 20, 2011 1:04 PM To: actionshoot...@carolina.rr.com ; mojave_meteori...@cox.net ; mpg4...@gmail.com ; meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! Ice rafting is the wind or water currents moving a sheet of ice like a raft. When the ice raft hits shore it breaks up and makes piles some that can be very deep. Cheers Steve Dunklee __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all!
Not in the desert. There they are being moved by wind On Sun Feb 20th, 2011 2:14 PM EST Stuart McDaniel wrote: So you saying these rocks are blown by the wind as they are floating on a sheet of ice? Stuart McDaniel Lawndale, NC Secr., Cleve. Co. Astronomical Society -Original Message- From: Steve Dunklee Sent: Sunday, February 20, 2011 1:04 PM To: actionshoot...@carolina.rr.com ; mojave_meteori...@cox.net ; mpg4...@gmail.com ; meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! Ice rafting is the wind or water currents moving a sheet of ice like a raft. When the ice raft hits shore it breaks up and makes piles some that can be very deep. Cheers Steve Dunklee __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Why Are Death Valley's Rocks Moving Themselves? -- not off-topic at all!
Hi Michael, IMHO, it's definitely ice-rafting. It happens on any desert playa that is hard enough, receives sufficient winter rains, and gets cold enough to freeze at night. In California, I've seen the rock furrows at Silver Dry Lake, Superior Dry Lake, Cuddeback Dry Lake and (most recently) Coyote Dry Lake. I've also seen them on some Nevada playas as well as the Alvord Desert in Oregon, and they occur in Arizona, as well. SoCal got a lot of rain this past December -- so much so that even after three weeks of dry weather in January the northern third of Coyote was under water. I've never seen this in the decade I've been going there, and sure enough I saw rock trails there for the first time last month. Bob Verish, Nick Gessler and I coauthored an abstract and presentation on this subject, and in particular its implications for meteorite recovery, at the 65th Annual Meeting of the Meteoritical Society in 2002: http://adsabs.harvard.edu/full/2002M%26PSA..37Q..51G Cheers, Rob -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com]On Behalf Of Michael Groetz Sent: Friday, February 18, 2011 5:24 PM To: Meteorite List Subject: [meteorite-list] OT (Sorta...) Why Are Death Valley's Rocks MovingThemselves? Interesting photo- wish I could crawl out of my chair in Ohio and go check those rocks out. I know this has been discussed on the list before. Have a good night. Mike http://www.foxnews.com/scitech/2011/02/18/death-valleys-rocks-moving-racetra ck-playa/ Why Are Death Valley's Rocks Moving Themselves? By Philip Schewe Published February 18, 2011 | Inside Science News Service Death Valley National Park contains many mysteries, including one of nature's strangest phenomena: rocks that seem to move around all on their own. In the remote, almost totally dry lakebed called Racetrack Playa, some of the rocks move themselves across the desert floor when people aren't watching. Scientists know the rocks move because they leave narrow tracks trailing behind them, but they haven't actually seen it happen. And although one can't entirely rule out the possibility of some prank being played, at least some of the rocks appear to be moving under natural circumstances. It doesn't rain often in Racetrack Playa, and when it does the lakebed can flood. The rocks don't float exactly, but the main explanation for their movement is that moisture can make the mud on which the rocks sit more slick, making it easier for high winds to push the rocks along. Another explanation offered is that the temporary deposit of water, chilled to form extensive sheets of ice, might help to reflect and focus the winds, making it easier for the rocks to move. The winds required to move rocks in this way would seem to be at the level of 100 mph or more. That's why the rocks are sometimes referred to as sailing stones. They are rare but they have been noticed in Racetrack Playa and a few other arid places around the world subject to occasional floods Ralph Lorenz, a scientist at Johns Hopkins University, offers a new explanation. The rocks are actually lifted up by the ice, or at least made more buoyant by the ice, making it easier for the rocks to migrate. If the rocks are moving about on ice rafts, the ground below cannot offer as much resistance against their motion and the winds needed for movement wouldn't have to be as great, he argued. So why hasn't the motion been observed? Movement happens for only tens of seconds, at intervals spaced typically by several years, said Lorenz. This would demand exceptional patience as well as luck. So, the rocks are probably traveling on the coldest and windiest days that occur over a period of several years. The most likely time would be in the very early dawn. Little wonder no one is around to witness the event. Lorenz and his colleagues would like to install inexpensive time-lapse monitoring of the Playa area, using digital cameras. The lakebed is about 2.5 miles long and 1.25 miles wide. They have also performed some laboratory tests by blowing on ice-assisted rocks. These simple tests support the ice-raft hypothesis. The results appear in the January 2011 issue of the American Journal of Physics. An additional reason for studying the rocks of Racetrack Playa is that its qualities resemble those at a drying-up lake on Saturn's moon Titan. Pictures taken by the Cassini-Huygens mission reveal what look like river channels, cobblestones, and lake beds or mud flats. Only at Titan's Ontario Lacus, as one interesting site is called, the runoff consists of liquid hydrocarbons, not water. Some pictures even seem to be showing a bathtub ring left by what is probably a drying lake. One of Lorenz's colleagues, Brian K. Jackson, who works at NASA's Goddard Space Flight Center, also likes the idea that their research at Racetrack Playa has a dual purpose. It's been exciting trying to solve a mystery that has
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? -- not off-topic at all!
Michael, Rob, List I encountered these rock trails on Red Dry Lake last year. Some were a hundred feet long or more! I saw two trails side by side that made a 10 degree turn at the same time, indicating to me a shift of wind and ice float direction. From article below: Movement happens for only tens of seconds, at intervals spaced typically by several years, said Lorenz I'm not sure this scenario makes sense. Why couldn't the ice float move 10's of feet or more at a time? I think the trails I saw, described above, contradict this theory. Sincerely, Larry Atkins IMCA # 1941 Ebay alienrockfarm -Original Message- From: Rob Matson mojave_meteori...@cox.net To: Michael Groetz mpg4...@gmail.com; Meteorite List meteorite-list@meteoritecentral.com Sent: Sat, Feb 19, 2011 3:06 pm Subject: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? -- not off-topic at all! Hi Michael, IMHO, it's definitely ice-rafting. It happens on any desert playa that is hard enough, receives sufficient winter rains, and gets cold enough to freeze at night. In California, I've seen the rock furrows at Silver Dry Lake, Superior Dry Lake, Cuddeback Dry Lake and (most recently) Coyote Dry Lake. I've also seen them on some Nevada playas as well as the Alvord Desert in Oregon, and they occur in Arizona, as well. SoCal got a lot of rain this past December -- so much so that even after three weeks of dry weather in January the northern third of Coyote was under water. I've never seen this in the decade I've been going there, and sure enough I saw rock trails there for the first time last month. Bob Verish, Nick Gessler and I coauthored an abstract and presentation on this subject, and in particular its implications for meteorite recovery, at the 65th Annual Meeting of the Meteoritical Society in 2002: http://adsabs.harvard.edu/full/2002M%26PSA..37Q..51G Cheers, Rob -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com]On Behalf Of Michael Groetz Sent: Friday, February 18, 2011 5:24 PM To: Meteorite List Subject: [meteorite-list] OT (Sorta...) Why Are Death Valley's Rocks MovingThemselves? Interesting photo- wish I could crawl out of my chair in Ohio and go check those rocks out. I know this has been discussed on the list before. Have a good night. Mike http://www.foxnews.com/scitech/2011/02/18/death-valleys-rocks-moving-racetra ck-playa/ Why Are Death Valley's Rocks Moving Themselves? By Philip Schewe Published February 18, 2011 | Inside Science News Service Death Valley National Park contains many mysteries, including one of nature's strangest phenomena: rocks that seem to move around all on their own. In the remote, almost totally dry lakebed called Racetrack Playa, some of the rocks move themselves across the desert floor when people aren't watching. Scientists know the rocks move because they leave narrow tracks trailing behind them, but they haven't actually seen it happen. And although one can't entirely rule out the possibility of some prank being played, at least some of the rocks appear to be moving under natural circumstances. It doesn't rain often in Racetrack Playa, and when it does the lakebed can flood. The rocks don't float exactly, but the main explanation for their movement is that moisture can make the mud on which the rocks sit more slick, making it easier for high winds to push the rocks along. Another explanation offered is that the temporary deposit of water, chilled to form extensive sheets of ice, might help to reflect and focus the winds, making it easier for the rocks to move. The winds required to move rocks in this way would seem to be at the level of 100 mph or more. That's why the rocks are sometimes referred to as sailing stones. They are rare but they have been noticed in Racetrack Playa and a few other arid places around the world subject to occasional floods Ralph Lorenz, a scientist at Johns Hopkins University, offers a new explanation. The rocks are actually lifted up by the ice, or at least made more buoyant by the ice, making it easier for the rocks to migrate. If the rocks are moving about on ice rafts, the ground below cannot offer as much resistance against their motion and the winds needed for movement wouldn't have to be as great, he argued. So why hasn't the motion been observed? Movement happens for only tens of seconds, at intervals spaced typically by several years, said Lorenz. This would demand exceptional patience as well as luck. So, the rocks are probably traveling on the coldest and windiest days that occur over a period of several years. The most likely time would be in the very early dawn. Little wonder no one is around to witness the event. Lorenz and his colleagues would like to install inexpensive time-lapse monitoring of the Playa area, using digital cameras. The lakebed is about 2.5 miles long and 1.25 miles wide. They have also
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? -- not off-topic at all!
There is no doubt whatsoever that wind plays a major part in it. I observed a large rock and a piece of galvanized sheet metal side by side about ten years ago. I recently observed the same rock and piece of metal but this time they were separated by about 50 feet. The trail of the rock went straight but the metal acting like a keel or rudder moved off in another direction. It is obvious that the metal acted like sail since its trail was much longer. You could tell the difference between true and apparent wind direction was about 12%. Best Regards, Adam - Original Message From: Larry Atkins thetop...@aol.com To: mojave_meteori...@cox.net; mpg4...@gmail.com; meteorite-list@meteoritecentral.com Sent: Sat, February 19, 2011 12:30:24 PM Subject: Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? -- not off-topic at all! Michael, Rob, List I encountered these rock trails on Red Dry Lake last year. Some were a hundred feet long or more! I saw two trails side by side that made a 10 degree turn at the same time, indicating to me a shift of wind and ice float direction. From article below: Movement happens for only tens of seconds, at intervals spaced typically by several years, said Lorenz I'm not sure this scenario makes sense. Why couldn't the ice float move 10's of feet or more at a time? I think the trails I saw, described above, contradict this theory. Sincerely, Larry Atkins IMCA # 1941 Ebay alienrockfarm -Original Message- From: Rob Matson mojave_meteori...@cox.net To: Michael Groetz mpg4...@gmail.com; Meteorite List meteorite-list@meteoritecentral.com Sent: Sat, Feb 19, 2011 3:06 pm Subject: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? -- not off-topic at all! Hi Michael, IMHO, it's definitely ice-rafting. It happens on any desert playa that is hard enough, receives sufficient winter rains, and gets cold enough to freeze at night. In California, I've seen the rock furrows at Silver Dry Lake, Superior Dry Lake, Cuddeback Dry Lake and (most recently) Coyote Dry Lake. I've also seen them on some Nevada playas as well as the Alvord Desert in Oregon, and they occur in Arizona, as well. SoCal got a lot of rain this past December -- so much so that even after three weeks of dry weather in January the northern third of Coyote was under water. I've never seen this in the decade I've been going there, and sure enough I saw rock trails there for the first time last month. Bob Verish, Nick Gessler and I coauthored an abstract and presentation on this subject, and in particular its implications for meteorite recovery, at the 65th Annual Meeting of the Meteoritical Society in 2002: http://adsabs.harvard.edu/full/2002M%26PSA..37Q..51G Cheers, Rob -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com]On Behalf Of Michael Groetz Sent: Friday, February 18, 2011 5:24 PM To: Meteorite List Subject: [meteorite-list] OT (Sorta...) Why Are Death Valley's Rocks MovingThemselves? Interesting photo- wish I could crawl out of my chair in Ohio and go check those rocks out. I know this has been discussed on the list before. Have a good night. Mike http://www.foxnews.com/scitech/2011/02/18/death-valleys-rocks-moving-racetra ck-playa/ Why Are Death Valley's Rocks Moving Themselves? By Philip Schewe Published February 18, 2011 | Inside Science News Service Death Valley National Park contains many mysteries, including one of nature's strangest phenomena: rocks that seem to move around all on their own. In the remote, almost totally dry lakebed called Racetrack Playa, some of the rocks move themselves across the desert floor when people aren't watching. Scientists know the rocks move because they leave narrow tracks trailing behind them, but they haven't actually seen it happen. And although one can't entirely rule out the possibility of some prank being played, at least some of the rocks appear to be moving under natural circumstances. It doesn't rain often in Racetrack Playa, and when it does the lakebed can flood. The rocks don't float exactly, but the main explanation for their movement is that moisture can make the mud on which the rocks sit more slick, making it easier for high winds to push the rocks along. Another explanation offered is that the temporary deposit of water, chilled to form extensive sheets of ice, might help to reflect and focus the winds, making it easier for the rocks to move. The winds required to move rocks in this way would seem to be at the level of 100 mph or more. That's why the rocks are sometimes referred to as sailing stones. They are rare but they have been noticed in Racetrack Playa and a few other arid places around the world subject to occasional floods Ralph Lorenz, a scientist at Johns Hopkins University, offers a new explanation. The rocks are actually lifted up by the ice, or at least made more
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? -- not off-topic at all!
Rock and Roll! ;-) --AL __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Why Are Death Valley's Rocks Moving Themselves? -- not off-topic at all!
AL kindly wrote: Rock and Roll! Chuck Berry, Bill Haley, or Elvis (the pelvis):-)) Bernd __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? -- not off-topic at all!
Hi Rob and all! I was out at Danby this last weekend. Some rocks on the dry lake had been on the move! There were a couple of rocks I noticed with marks about 1 foot long. There were also broken bush limbs with same marks. This area was under water and very muddy for the last month or so. Although it did get below freezing a few times, I am thinking the water had a big part in the movement, along with the wind. That mud gets slicker than snot when wet (I learned that several times the hard way over the years). The tracks I noticed showed the rocks moving North or little North of the Old Woman range!! Cheers! Jim Wooddell On Sat, Feb 19, 2011 at 1:06 PM, Rob Matson mojave_meteori...@cox.net wrote: Hi Michael, IMHO, it's definitely ice-rafting. It happens on any desert playa that is hard enough, receives sufficient winter rains, and gets cold enough to freeze at night. In California, I've seen the rock furrows at Silver Dry Lake, Superior Dry Lake, Cuddeback Dry Lake and (most recently) Coyote Dry Lake. I've also seen them on some Nevada playas as well as the Alvord Desert in Oregon, and they occur in Arizona, as well. __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all!
Would you please explain what is meant by ice-rafting in laymen's terms?? Stuart McDaniel Lawndale, NC Secr., Cleve. Co. Astronomical Society -Original Message- From: Rob Matson Sent: Saturday, February 19, 2011 3:06 PM To: Michael Groetz ; Meteorite List Subject: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! Hi Michael, IMHO, it's definitely ice-rafting. It happens on any desert playa that is hard enough, receives sufficient winter rains, and gets cold enough to freeze at night. In California, I've seen the rock furrows at Silver Dry Lake, Superior Dry Lake, Cuddeback Dry Lake and (most recently) Coyote Dry Lake. I've also seen them on some Nevada playas as well as the Alvord Desert in Oregon, and they occur in Arizona, as well. SoCal got a lot of rain this past December -- so much so that even after three weeks of dry weather in January the northern third of Coyote was under water. I've never seen this in the decade I've been going there, and sure enough I saw rock trails there for the first time last month. Bob Verish, Nick Gessler and I coauthored an abstract and presentation on this subject, and in particular its implications for meteorite recovery, at the 65th Annual Meeting of the Meteoritical Society in 2002: http://adsabs.harvard.edu/full/2002M%26PSA..37Q..51G Cheers, Rob -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com]On Behalf Of Michael Groetz Sent: Friday, February 18, 2011 5:24 PM To: Meteorite List Subject: [meteorite-list] OT (Sorta...) Why Are Death Valley's Rocks MovingThemselves? Interesting photo- wish I could crawl out of my chair in Ohio and go check those rocks out. I know this has been discussed on the list before. Have a good night. Mike http://www.foxnews.com/scitech/2011/02/18/death-valleys-rocks-moving-racetra ck-playa/ Why Are Death Valley's Rocks Moving Themselves? By Philip Schewe Published February 18, 2011 | Inside Science News Service Death Valley National Park contains many mysteries, including one of nature's strangest phenomena: rocks that seem to move around all on their own. In the remote, almost totally dry lakebed called Racetrack Playa, some of the rocks move themselves across the desert floor when people aren't watching. Scientists know the rocks move because they leave narrow tracks trailing behind them, but they haven't actually seen it happen. And although one can't entirely rule out the possibility of some prank being played, at least some of the rocks appear to be moving under natural circumstances. It doesn't rain often in Racetrack Playa, and when it does the lakebed can flood. The rocks don't float exactly, but the main explanation for their movement is that moisture can make the mud on which the rocks sit more slick, making it easier for high winds to push the rocks along. Another explanation offered is that the temporary deposit of water, chilled to form extensive sheets of ice, might help to reflect and focus the winds, making it easier for the rocks to move. The winds required to move rocks in this way would seem to be at the level of 100 mph or more. That's why the rocks are sometimes referred to as sailing stones. They are rare but they have been noticed in Racetrack Playa and a few other arid places around the world subject to occasional floods Ralph Lorenz, a scientist at Johns Hopkins University, offers a new explanation. The rocks are actually lifted up by the ice, or at least made more buoyant by the ice, making it easier for the rocks to migrate. If the rocks are moving about on ice rafts, the ground below cannot offer as much resistance against their motion and the winds needed for movement wouldn't have to be as great, he argued. So why hasn't the motion been observed? Movement happens for only tens of seconds, at intervals spaced typically by several years, said Lorenz. This would demand exceptional patience as well as luck. So, the rocks are probably traveling on the coldest and windiest days that occur over a period of several years. The most likely time would be in the very early dawn. Little wonder no one is around to witness the event. Lorenz and his colleagues would like to install inexpensive time-lapse monitoring of the Playa area, using digital cameras. The lakebed is about 2.5 miles long and 1.25 miles wide. They have also performed some laboratory tests by blowing on ice-assisted rocks. These simple tests support the ice-raft hypothesis. The results appear in the January 2011 issue of the American Journal of Physics. An additional reason for studying the rocks of Racetrack Playa is that its qualities resemble those at a drying-up lake on Saturn's moon Titan. Pictures taken by the Cassini-Huygens mission reveal what look like river channels, cobblestones, and lake beds or mud flats. Only at Titan's Ontario Lacus, as one interesting site is called, the runoff
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all!
ice rafting is a misleading term, it actually has nothing to do with ice. The term is used to describe what happens when the martian blood vessels inside the rock come to life and begin the process of animating the stone so it can move. ;) -- Mike Gilmer - Galactic Stone Ironworks Meteorites Website - http://www.galactic-stone.com Facebook - http://www.facebook.com/galacticstone News Feed - http://www.galactic-stone.com/rss/126516 Twitter - http://twitter.com/galacticstone Meteorite Top List - http://meteorite.gotop100.com EOM - http://www.encyclopedia-of-meteorites.com/collection.aspx?id=1564 --- On 2/19/11, Stuart McDaniel actionshoot...@carolina.rr.com wrote: Would you please explain what is meant by ice-rafting in laymen's terms?? Stuart McDaniel Lawndale, NC Secr., Cleve. Co. Astronomical Society -Original Message- From: Rob Matson Sent: Saturday, February 19, 2011 3:06 PM To: Michael Groetz ; Meteorite List Subject: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! Hi Michael, IMHO, it's definitely ice-rafting. It happens on any desert playa that is hard enough, receives sufficient winter rains, and gets cold enough to freeze at night. In California, I've seen the rock furrows at Silver Dry Lake, Superior Dry Lake, Cuddeback Dry Lake and (most recently) Coyote Dry Lake. I've also seen them on some Nevada playas as well as the Alvord Desert in Oregon, and they occur in Arizona, as well. SoCal got a lot of rain this past December -- so much so that even after three weeks of dry weather in January the northern third of Coyote was under water. I've never seen this in the decade I've been going there, and sure enough I saw rock trails there for the first time last month. Bob Verish, Nick Gessler and I coauthored an abstract and presentation on this subject, and in particular its implications for meteorite recovery, at the 65th Annual Meeting of the Meteoritical Society in 2002: http://adsabs.harvard.edu/full/2002M%26PSA..37Q..51G Cheers, Rob -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com]On Behalf Of Michael Groetz Sent: Friday, February 18, 2011 5:24 PM To: Meteorite List Subject: [meteorite-list] OT (Sorta...) Why Are Death Valley's Rocks MovingThemselves? Interesting photo- wish I could crawl out of my chair in Ohio and go check those rocks out. I know this has been discussed on the list before. Have a good night. Mike http://www.foxnews.com/scitech/2011/02/18/death-valleys-rocks-moving-racetra ck-playa/ Why Are Death Valley's Rocks Moving Themselves? By Philip Schewe Published February 18, 2011 | Inside Science News Service Death Valley National Park contains many mysteries, including one of nature's strangest phenomena: rocks that seem to move around all on their own. In the remote, almost totally dry lakebed called Racetrack Playa, some of the rocks move themselves across the desert floor when people aren't watching. Scientists know the rocks move because they leave narrow tracks trailing behind them, but they haven't actually seen it happen. And although one can't entirely rule out the possibility of some prank being played, at least some of the rocks appear to be moving under natural circumstances. It doesn't rain often in Racetrack Playa, and when it does the lakebed can flood. The rocks don't float exactly, but the main explanation for their movement is that moisture can make the mud on which the rocks sit more slick, making it easier for high winds to push the rocks along. Another explanation offered is that the temporary deposit of water, chilled to form extensive sheets of ice, might help to reflect and focus the winds, making it easier for the rocks to move. The winds required to move rocks in this way would seem to be at the level of 100 mph or more. That's why the rocks are sometimes referred to as sailing stones. They are rare but they have been noticed in Racetrack Playa and a few other arid places around the world subject to occasional floods Ralph Lorenz, a scientist at Johns Hopkins University, offers a new explanation. The rocks are actually lifted up by the ice, or at least made more buoyant by the ice, making it easier for the rocks to migrate. If the rocks are moving about on ice rafts, the ground below cannot offer as much resistance against their motion and the winds needed for movement wouldn't have to be as great, he argued. So why hasn't the motion been observed? Movement happens for only tens of seconds, at intervals spaced typically by several years, said Lorenz. This would demand exceptional patience as well as luck. So, the rocks are probably traveling on the coldest and windiest days
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all!
Ah, so rocks are truly migratory then! Ed - Original Message - From: Michael Gilmer meteoritem...@gmail.com To: Stuart McDaniel actionshoot...@carolina.rr.com Cc: Michael Groetz mpg4...@gmail.com; Meteorite List meteorite-list@meteoritecentral.com; Rob Matson mojave_meteori...@cox.net Sent: Saturday, February 19, 2011 11:28 PM Subject: Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! ice rafting is a misleading term, it actually has nothing to do with ice. The term is used to describe what happens when the martian blood vessels inside the rock come to life and begin the process of animating the stone so it can move. ;) -- Mike Gilmer - Galactic Stone Ironworks Meteorites Website - http://www.galactic-stone.com Facebook - http://www.facebook.com/galacticstone News Feed - http://www.galactic-stone.com/rss/126516 Twitter - http://twitter.com/galacticstone Meteorite Top List - http://meteorite.gotop100.com EOM - http://www.encyclopedia-of-meteorites.com/collection.aspx?id=1564 --- On 2/19/11, Stuart McDaniel actionshoot...@carolina.rr.com wrote: Would you please explain what is meant by ice-rafting in laymen's terms?? Stuart McDaniel Lawndale, NC Secr., Cleve. Co. Astronomical Society -Original Message- From: Rob Matson Sent: Saturday, February 19, 2011 3:06 PM To: Michael Groetz ; Meteorite List Subject: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! Hi Michael, IMHO, it's definitely ice-rafting. It happens on any desert playa that is hard enough, receives sufficient winter rains, and gets cold enough to freeze at night. In California, I've seen the rock furrows at Silver Dry Lake, Superior Dry Lake, Cuddeback Dry Lake and (most recently) Coyote Dry Lake. I've also seen them on some Nevada playas as well as the Alvord Desert in Oregon, and they occur in Arizona, as well. SoCal got a lot of rain this past December -- so much so that even after three weeks of dry weather in January the northern third of Coyote was under water. I've never seen this in the decade I've been going there, and sure enough I saw rock trails there for the first time last month. Bob Verish, Nick Gessler and I coauthored an abstract and presentation on this subject, and in particular its implications for meteorite recovery, at the 65th Annual Meeting of the Meteoritical Society in 2002: http://adsabs.harvard.edu/full/2002M%26PSA..37Q..51G Cheers, Rob -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com]On Behalf Of Michael Groetz Sent: Friday, February 18, 2011 5:24 PM To: Meteorite List Subject: [meteorite-list] OT (Sorta...) Why Are Death Valley's Rocks MovingThemselves? Interesting photo- wish I could crawl out of my chair in Ohio and go check those rocks out. I know this has been discussed on the list before. Have a good night. Mike http://www.foxnews.com/scitech/2011/02/18/death-valleys-rocks-moving-racetra ck-playa/ Why Are Death Valley's Rocks Moving Themselves? By Philip Schewe Published February 18, 2011 | Inside Science News Service Death Valley National Park contains many mysteries, including one of nature's strangest phenomena: rocks that seem to move around all on their own. In the remote, almost totally dry lakebed called Racetrack Playa, some of the rocks move themselves across the desert floor when people aren't watching. Scientists know the rocks move because they leave narrow tracks trailing behind them, but they haven't actually seen it happen. And although one can't entirely rule out the possibility of some prank being played, at least some of the rocks appear to be moving under natural circumstances. It doesn't rain often in Racetrack Playa, and when it does the lakebed can flood. The rocks don't float exactly, but the main explanation for their movement is that moisture can make the mud on which the rocks sit more slick, making it easier for high winds to push the rocks along. Another explanation offered is that the temporary deposit of water, chilled to form extensive sheets of ice, might help to reflect and focus the winds, making it easier for the rocks to move. The winds required to move rocks in this way would seem to be at the level of 100 mph or more. That's why the rocks are sometimes referred to as sailing stones. They are rare but they have been noticed in Racetrack Playa and a few other arid places around the world subject to occasional floods Ralph Lorenz, a scientist at Johns Hopkins University, offers a new explanation. The rocks are actually lifted up by the ice, or at least made more buoyant by the ice, making it easier for the rocks to migrate. If the rocks are moving about on ice rafts, the ground below cannot offer as much resistance
Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all!
OK, OK, yeah yeah yeah. Stuart McDaniel Lawndale, NC Secr., Cleve. Co. Astronomical Society -Original Message- From: Michael Gilmer Sent: Saturday, February 19, 2011 11:28 PM To: Stuart McDaniel Cc: Rob Matson ; Michael Groetz ; Meteorite List Subject: Re: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! ice rafting is a misleading term, it actually has nothing to do with ice. The term is used to describe what happens when the martian blood vessels inside the rock come to life and begin the process of animating the stone so it can move. ;) -- Mike Gilmer - Galactic Stone Ironworks Meteorites Website - http://www.galactic-stone.com Facebook - http://www.facebook.com/galacticstone News Feed - http://www.galactic-stone.com/rss/126516 Twitter - http://twitter.com/galacticstone Meteorite Top List - http://meteorite.gotop100.com EOM - http://www.encyclopedia-of-meteorites.com/collection.aspx?id=1564 --- On 2/19/11, Stuart McDaniel actionshoot...@carolina.rr.com wrote: Would you please explain what is meant by ice-rafting in laymen's terms?? Stuart McDaniel Lawndale, NC Secr., Cleve. Co. Astronomical Society -Original Message- From: Rob Matson Sent: Saturday, February 19, 2011 3:06 PM To: Michael Groetz ; Meteorite List Subject: [meteorite-list] Why Are Death Valley's Rocks Moving Themselves? --not off-topic at all! Hi Michael, IMHO, it's definitely ice-rafting. It happens on any desert playa that is hard enough, receives sufficient winter rains, and gets cold enough to freeze at night. In California, I've seen the rock furrows at Silver Dry Lake, Superior Dry Lake, Cuddeback Dry Lake and (most recently) Coyote Dry Lake. I've also seen them on some Nevada playas as well as the Alvord Desert in Oregon, and they occur in Arizona, as well. SoCal got a lot of rain this past December -- so much so that even after three weeks of dry weather in January the northern third of Coyote was under water. I've never seen this in the decade I've been going there, and sure enough I saw rock trails there for the first time last month. Bob Verish, Nick Gessler and I coauthored an abstract and presentation on this subject, and in particular its implications for meteorite recovery, at the 65th Annual Meeting of the Meteoritical Society in 2002: http://adsabs.harvard.edu/full/2002M%26PSA..37Q..51G Cheers, Rob -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com]On Behalf Of Michael Groetz Sent: Friday, February 18, 2011 5:24 PM To: Meteorite List Subject: [meteorite-list] OT (Sorta...) Why Are Death Valley's Rocks MovingThemselves? Interesting photo- wish I could crawl out of my chair in Ohio and go check those rocks out. I know this has been discussed on the list before. Have a good night. Mike http://www.foxnews.com/scitech/2011/02/18/death-valleys-rocks-moving-racetra ck-playa/ Why Are Death Valley's Rocks Moving Themselves? By Philip Schewe Published February 18, 2011 | Inside Science News Service Death Valley National Park contains many mysteries, including one of nature's strangest phenomena: rocks that seem to move around all on their own. In the remote, almost totally dry lakebed called Racetrack Playa, some of the rocks move themselves across the desert floor when people aren't watching. Scientists know the rocks move because they leave narrow tracks trailing behind them, but they haven't actually seen it happen. And although one can't entirely rule out the possibility of some prank being played, at least some of the rocks appear to be moving under natural circumstances. It doesn't rain often in Racetrack Playa, and when it does the lakebed can flood. The rocks don't float exactly, but the main explanation for their movement is that moisture can make the mud on which the rocks sit more slick, making it easier for high winds to push the rocks along. Another explanation offered is that the temporary deposit of water, chilled to form extensive sheets of ice, might help to reflect and focus the winds, making it easier for the rocks to move. The winds required to move rocks in this way would seem to be at the level of 100 mph or more. That's why the rocks are sometimes referred to as sailing stones. They are rare but they have been noticed in Racetrack Playa and a few other arid places around the world subject to occasional floods Ralph Lorenz, a scientist at Johns Hopkins University, offers a new explanation. The rocks are actually lifted up by the ice, or at least made more buoyant by the ice, making it easier for the rocks to migrate. If the rocks are moving about on ice rafts, the ground below cannot offer as much resistance against their motion and the winds needed for movement wouldn't have to be as great, he
