Ice Crystal Formation Near Anchorage, Alaska

March 11, 2011

AlaskaFrost_EPOD2 (3) 
Photographer: Bill Burton 
Summary Author: Bill Burton; Jim Foster

The beautiful ice crystal formations shown above were growing on a tree stump next to a ski trail on the outskirts of Anchorage, Alaska. The weather in Anchorage mid January 2011 had been clear, calm and very cold: below zero F or around -18 C for several consecutive days. Such conditions facilitate ice crystal growth. Some of these impressive crystals were over two inches (5 cm) in diameter. The fine growth ring-like features perhaps reflect daily fluctuations in water vapor availability or relative humidity. These crystals coated numerous surfaces in lower, protected areas regardless of sun or shade, but were totally absent on exposed ridges where light breezes disturbed the still air, inhibiting crystal growth. Photo taken on January 17, 2011.

Photo details: Camera Maker: Canon; Camera Model: Canon PowerShot G6; Focal Length: 23.0mm; Aperture: f/3.5; Exposure Time: 0.010 s (1/100); ISO equiv: 800; Exposure Bias: none; Metering Mode: Matrix; White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB.