Eben Ice Caves
May 08, 2013
Photographer: Nina Asunto; Nina’s Web site/blog
Summary Authors: Nina Asunto; Jim Foster
The Eben Ice Caves shown above are found in the Rock River Canyon Wilderness of the Hiawatha National Forest, in the Upper Peninsula (UP) of Michigan. Rock River Canyon is sprinkled with sandstone outcrops that over tens of thousands of years have eroded to form concave overhangs. Ground water seeping over the edge of the canyon walls and flowing gently down through the sandstone freezes during the winter months. When that happens these stunning curtains of ice are the result, closing off the outcrops and creating caves of a sort. The green glow is caused by absorption and scattering of light. The formations of ice are sufficiently thick to absorb the longer wavelength red and yellow colors. We see the blue and green colors that aren’t readily absorbed. Photos taken on February 27, 2012.
Photo details: Top - Camera: Canon PowerShot SD950 IS; Exposure: 0.002 sec (1/500); Aperture: f/2.8; Focal Length: 7.7 mm; ISO Speed: 400. Bottom - same except: Exposure: 0.017 sec (1/60); ISO Speed: 125.