Pressure ridge, Beaufort Sea. Anglo-American Polar Expedition. Canning district, Northern Alaska region, Alaska. C. 1910. – ID. Leffingwell, E.K. 5 – lek00005 – U.S. Geological Survey – Public domain image
Pressure ridge, Beaufort Sea. Anglo-American Polar Expedition. Canning district, Northern Alaska region, Alaska. C. 1910. – ID. Leffingwell, E.K. 5 – lek00005 – U.S. Geological Survey – Public domain image
Cormac James 
