Frazil Ice on the Allegheny River

March 03, 2012


Photographer: Heather Renyck
Summary Author: Heather Renyck

This photo shows a buildup of frazil ice along the Allegheny River near Allegany, New York. It was taken during one of the short stretches this winter when temperatures were below freezing for several days. Frazil ice is the first stage in river ice formation. As the crystals begin to form and grow, they're interrupted by water movement. As a result, sheets of ice are created that contain a mixture of crystals and liquid water, producing a slushy appearance.

Frazil3I noticed that as the river carried the frazil slush downstream, rafts of ice accumulated along the riverbanks. The sight of the ice floes colliding with each other were quite reminiscent (to me, at least) of watching the movement of fresh lava in Hawaii. Additionally, noises made during these collisions were similar to the metallic sound heard when the cooling upper surface of hardening lava interacts with semisolid lava pieces. Less than 24 hours after this icy build up occurred, warming temperatures and rainfall melted it all. Photo taken on January 16, 2012.

Photo details: Top - Camera Maker: OLYMPUS IMAGING CORP.; Camera Model: E-510; Focal Length: 9.0mm; Aperture: f/6.3; Exposure Time: 0.010 s (1/100); ISO equiv: 100; Exposure Bias: none; Metering Mode: Matrix; Exposure: Creative Program (based towards depth of field); White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB; Software: QuickTime 7.6.6. Left - Same except: Focal Length: 14.0mm; Aperture: f/7.1; Exposure Time: 0.0063 s (1/160).