MSGID: 1:317/3 63f65865   
   PID: hpt/lnx 1.9.0-cur 2019-01-08   
   TID: hpt/lnx 1.9.0-cur 2019-01-08   
    EPOD - a service of USRA   
      
   The Earth Science Picture of the Day (EPOD) highlights the diverse processes   
   and phenomena which shape our planet and our lives. EPOD will collect and   
   archive photos, imagery, graphics, and artwork with short explanatory   
   captions and links exemplifying features within the Earth system. The   
   community is invited to contribute digital imagery, short captions and   
   relevant links.   
      
      
    Spiral Pattern on an Icy Puddle   
      
      February 22, 2023   
      
       Ice spiral   
      
      Photographer:  Mark Hendrickson   
      
      Summary Authors:  Mark Hendrickson;  Jim Foster   
      
      I’ve have seen  concentric ice rings in puddles, but this is the   
      first true spiral I’ve observed. This photo was taken about 17 miles   
      (27 km) northeast of Payson, Arizona on January 21, 2023. The overnight   
      low was 18ºF (-8 C), and at the time of the photo the temperature had   
      climbed to 28ºF (-2 C). The surface of the puddle was about 2 ft (.6 m)   
      across and was completely frozen. It's very likely that the ice didn't   
      reach the bottom of this little puddle.   
      
      A number of factors can lead to odd patterns on  icy surfaces. Note   
      the fractures (white lines) in the ice at left, in the only ring not   
      part of the spiral formation. The next ring starts the actual spiral.   
      So, it seems that there was an initial sheet across the puddle, and   
      when the ice became sufficiently thick (perhaps a few mm) only one more   
      crack formed. With just a single crack, as the water beneath   
      transferred to the ice and shrunk (contracted) toward the center, the   
      crack grew and spiraled inward. However, exactly how these spirals   
      formed is still a bit of a mystery. Thanks to Steven Arcone and Doug   
      Stith for their help with this.   
      
      
      Payson, Arizona Coordinates: 34.2309, -111.3251   
      
      
   Related EPODs   
      
       Spiral Pattern on an Icy Puddle  Winter’s Black and White — and   
      Gray — World  Pearl Necklace or Frozen Spiderweb?  Fernlike Snow   
      Crystal  Frost Crack in Linden Tree  Triboluminescence Observed   
      on Perito Moreno Glacier   
       More...   
      
   Cryosphere Links   
      
        *  Guide to Frost   
        *  What is the Cryosphere?   
        *  Bentley Snow Crystals   
        *  Glaciers of the World   
        *  Ice, Snow, and Glaciers: The Water Cycle   
        *  The National Snow and Ice Data Center Google Earth Images   
        *  Snow and Ice Crystals   
      
   -   
      Earth Science Picture of the Day is a service of the  Universities   
      Space Research Association.   
      
   https://epod.usra.edu   
       
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