Here’s entry #9 in the ‘big ice’ photo contest – this one comes to us courtesy of the Government of Alberta. Here, River Engineer Jim Choles is shown standing beside the shear wall left behind after the release of an ice jam at this site on the Athabasca River, near Fort McMurray, Alberta.
The release caused water levels just downstream to rise more than 4 m (~12 feet) in less than 15 minutes. The water level rise rate peaked at 0.81 m (~2 feet) per minute. It’s the biggest ice jam release event documented to date.*
*Kowalczyk Hutchison, T. and F. Hicks (2007)“Observations of Ice Jam Release Events on the Athabasca
River, AB” Canadian Journal of Civil Engineering, 34 (4) 473-484.