Glacial Potholes in Finland
October 16, 2013
Photographer: Matias Takala; Matias' Web site
Summary Author: Matias Takala
Featured above is one of 20 glacial potholes found on a steep slope in Askola, Finland. The largest of these has a diameter of 14 ft (4.2 m) and is 34 ft (10.3 m) deep -- the pothole shown here is smaller and shallower. These fluvioglacial potholes were formed during the last ice age, over 10,000 years ago, when stones and gravel carried by glacial meltwater began to grind holes into the bedrock. In a few of the potholes these grinding stones still remain. This site was discovered in 1950. In 1964 the potholes were emptied of soil and organic matter, and the area was first opened to the public. Photo taken on September 7, 2013.
Photo details: Camera Model: NIKON D7000; Focal Length: 11.5mm (35mm equivalent: 17mm); Aperture: f/10.0; Exposure Time: 0.010 s (1/100); ISO equiv: 6400; Software: GIMP 2.6.12.