Breakup on the Athabasca River, AB (Canada), April 21, 2003
This picture shows the remnant ice left behind after successive ice jam release events on the Athabasca River near Fort McMurray, Alberta. The lower ice is the shear wall left behind as a result of a local ice jam release event. The bigger pieces sitting on top were left behind after an even bigger wave of ice and water passed the same site. That big piece of ice in the middle was more than 2 meters (~6 ft) tall and about 2 metres in diameter.
(photo by Faye Hicks, UofA River Ice Group: Nikon E950, f/11.4, ISO-80, FL 20mm, 1/215 sec. exposure)