Circles in ice and snow

[Ellipse]

http://www.kornsirkler.org/Norske-is-sno/norske-is-sno.htm
http://infinite8.livejournal.com/
http://www.kp.ru/daily/23412/34478/

some possible tracks I think :
-Human made
-Metro vibrations
-Energy surge as mention by C's (I must search the excerpt)
-Side effect off seismic weapon

Perhaps related : "Point spread function" : http://en.wikipedia.org/wiki/Point_spread_function

 

[Juba]

Hello Ellipse,

this is interesting indeed, but as much I understand thermodynamic, explanation could be plausible, like on attached photo, person who arranged construction actually made minimal differences in air ionization & temperature just by dropping stones on ice (with that air flow allowed snow to be formed around anomalies (stones)).

more on: http://www.wunderground.com/wximage/viewsingleimage.html?mode=singleimage&handle=TopazLN&number=192&album_id=61&thumbstart=0&gallery=

as explained by TopazLN

My camera overexposed this shot, but I liked the effect. The day before I took this shot, my son and I had thrown some of these rocks out onto the frozen surface of Rattlesnake Lake (they made such a cool sound when they skipped across the ice!). Today we found those rocks surrounded by snow!

, this kind of constructions could have other explanations like: local air micro movements, acidity (PH value) of snow, ice or soil that can make interesting circular or bull eye patterns on low icy temperatures.
If we successfully exclude all rudimentary 3d STS tools and twists of nature than would be good to remember that crop cycles had a simple start, I guess if 6d decided to change drawing board, why not on snow and ice, I do not believe this will be any kind of problem for them:)

 

[Ellipse]

Yes, perhaps a clue. More investigations need. :)

 

[Juba]

Or perhaps question for C's:)