Reflection Glitter Path and Blue Color

September 02, 2011

Iceberg glitter path (2)

: John Adam
Summary Author: John Adam
This well defined glitter path is produced by sunlight reflected off the iceberg and then reflected yet again in a set of parallel waves in the foreground. Note the soft pure blue color from the underside of the ice. What produces this color? Longer wavelengths present in the incident white light are preferentially absorbed by the ice, resulting in reflected light that is dominated by shorter wavelengths towards the blue end of the spectrum. Sometimes this light is very blue – click here. This definitely is not the same mechanism (Raleigh scattering) as that which gives the sky its (less pure) blue color. The particular chunk of ice shown above, about 100 ft (31 m) in width, had broken off from the Sawyer Glacier, located about a mile (1.6 km) from the end of the 30 mi (48 km) long Tracy Arm fiord, which is approximately about 70 mi (112 km) south of Juneau, Alaska. Photo taken in June 2011.

Photo Details: Camera: OLYMPUS SP570UZ; Focal Length: 56.5mm; Aperture: f/4.6; Exposure Time: 0.0016 s (1/640); ISO equiv: 64.