Photo of the Day 290

Calving Glacier, Matanuska Glacier, Alaska, 2007

Photograph by James Balog

It takes ice about 250 years to travel the 24 miles (39 kilometers) from the origin of Alaska's Matanuska Glacier to its terminus, where icebergs like this one calve into the Matanuska River.

(Photo shot on assignment for, but not published in, "The Big Thaw," June 2007, National Geographic magazine)