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Post by icefisher on Apr 17, 2009 13:48:22 GMT
The likely shapes are like mountain ranges, not pyramids. A pyramid has a larger mass underneath, and doesn't need the same depth, but any ridge shape needs the 9x depth underneath. Exactly! An experiment with icecubes would demonstrate that a pyramid shaped icecube is going to go point down unless propped up by other ice. The bouyancy of the ice will cause torque on the spreading submerged corners that will quickly go out of balance. Its the opposite problem of balancing a pyramid on its nose on a table.
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Post by ron on Apr 18, 2009 2:25:15 GMT
But the stuff gets pushed up onto GIANT sheets of ice... if the sheets support the weight (ie doesn't snap off) it looks just like the ice pushed up onto land... no?
If it does snap off, the area that snaps off likely breaks up and gets pushed up onto the ice behind it. At some point the tides/wind/whatever may ease and allow the edge to refreeze, leaving a large pile on top of a (relatively) thin immense sheet.
I dunno, just thinking about it, but I've seen what Arctic ice looks like that's pushed up onto shore -- I've stood on it.
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Post by hilbert on Apr 18, 2009 15:00:54 GMT
This sounds somewhat plausible. I think that ice will not support much shear stress, however (it probably snaps off fairly easily).
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Post by icefisher on Apr 18, 2009 17:21:27 GMT
But the stuff gets pushed up onto GIANT sheets of ice... if the sheets support the weight (ie doesn't snap off) it looks just like the ice pushed up onto land... no? If it does snap off, the area that snaps off likely breaks up and gets pushed up onto the ice behind it. At some point the tides/wind/whatever may ease and allow the edge to refreeze, leaving a large pile on top of a (relatively) thin immense sheet. I dunno, just thinking about it, but I've seen what Arctic ice looks like that's pushed up onto shore -- I've stood on it. I would think that most of the time the sheared ice is getting pushed down. . . .like icecubes in a glass of water. At the beginning it might sometimes goes up. But once the colliding ice has a sufficiently large pile of rubble at the point of collision logically all future shearing goes down. I don't know if this rubble getting shoved under the pile stays in place and refreezes to the same spot or if it becomes an undersheet iceberg, like ice cubes piled in a glass of water, but there is a bouyancy that keeps this stuff touching the bottom of the pile. But I agree with Kiwi there is 9 times the ice under sealevel as above and how it works at these fracture points translates into some kind unknown equation dependent upon water/ice temperatures and currents under the ice.
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Post by ron on Apr 18, 2009 20:50:44 GMT
I must admit that I never thought of that possibility, and it is intriguing. However I'd think that the floating debris/chunks/rubble/whatever would get lifted up and pushed onto the sheet by wave action, since the ice sheet is 9 times thicker below the water line, give or take.
Interesting stuff to think about!
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Post by jimg on May 7, 2009 17:01:57 GMT
So Catlin just got a resupply and they're still out on the ice after what is considered the latest safe date for an aircraft pickup.
This begs the question:
Are they expecting a submarine to surface at the North Pole to rescue them?
I think Prince Charles would have the connections to pull off a stunt like that.
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Post by poitsplace on May 7, 2009 17:14:51 GMT
So Catlin just got a resupply and they're still out on the ice after what is considered the latest safe date for an aircraft pickup. This begs the question: Are they expecting a submarine to surface at the North Pole to rescue them? I think Prince Charles would have the connections to pull off a stunt like that. What exactly do they hope to accomplish? Are they losing it mentally? Are they TRYING to cause a commotion so there will be sensational headlines about needing rescue due to arctic warming? Are they perhaps giving different numbers with ice in reality being significantly thicker than expected and/or reported?
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Post by msphar on May 7, 2009 17:58:58 GMT
It will be interesting to contrast the reported results of these Brits with those found by the flying Germans.
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Post by gettingchilly on May 7, 2009 18:45:52 GMT
Maybe the abandoned eco sailor's yacht will drift in through all the melted ice and they will wake up next to their alternative ride home. They can sail home like hero's and might not even have to be rescued by an oil tanker.
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Post by msphar on May 7, 2009 20:53:42 GMT
What happened to the yacht. It sounded like the crew survived through the worst of the storm but abandoned ship when the wind was subsiding ? Sorry to see a fellow sailor give up on their vessel so willingly. Speaking of their intended course, isn't there still a lot of ice in the way ? Where is Nuuk on the coast of Greenland ? Yes, I am unfamiliar with the local geography.
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Post by jimg on May 7, 2009 22:45:42 GMT
Maybe Pugh is breaking out his Kayak to go get them.
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Post by Belushi TD on May 8, 2009 22:41:08 GMT
Perhaps the reason they're staying out past the latest "safe landing" date is because the ice is much thicker (and hence, safe to land a plane on) than they expected.
Seems to me that would be a pretty good explanation. I seem to remember someone saying that they were going to show ice thicknesses as they went, and they didn't. Does anyone know if they released ANY ice thickness data?
How thick a layer of ice do you need to land a small plane on skis on anyway? I think they open the ice runway here in Anchorage for Lake Hood when the ice is 20 or 24 inches thick. I could be wrong about that, so don't take that as gospel.
Belushi TD
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Post by jimg on May 8, 2009 22:58:09 GMT
They do have an "Ice Report" available as a 4/14/09.
Complete with such technical jargon as "thick" "thicker" "thinner"
etc, etc. I didn't see any numerical values for current thickness.
It does indicate that they are traveling on "thick" first year ice. Whatever that means.
I sent off an email to them, no response yet, but there was a new posting on their blog that talked of extraction in 7-10 days. They are heading for an area that should provide an area for two aircraft to land and refuel.
(I liked this comment:) "Barrels are always marked up with the owner’s details, to avoid them being simply abandoned. "
Dear Mr. Polar Bear, if you find this fuel drum, please return to:
I'm still betting on the dramatic submarine rescue.
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Post by msphar on May 9, 2009 4:58:22 GMT
The Catlin three will soon be off the ice. Good news, 7-10 days more of this story, I'm sure they are looking forward to returning to civilization. Imagine three bodies climbing into their respective sleeping bags, night after night in that little pup tent. It must stink to the heavens. I'm sure they work up a mild sweat pulling those sleds every day, on top of consuming 7,000 calories of food each, and no showers in the last 70 days or the next 10, or the following 2 while they are flying back to the world. That first hot shower will be much discussed and anticipated no doubt. They deserve awards for the "grungiest green" of the century regardless of the merit of their science.
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Post by dopeydog on May 13, 2009 13:47:19 GMT
So I read they are out of there today. Hardly a whimper in the media (main stream or not). As far as I can tell, they did not even accomplish their main mission: Publicity. I wonder if they will even publish any of the raw data collected.
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