26-G-5963
January 1962. Original caption: “Personnel aboard the Coast Guard Cutter Evergreen, oceanographic vessel for the International Ice Patrol, are reading and recording temperatures of water samples collected in Nansen bottles during an oceanographic survey in the Grand Banks. Temperatures read to a thousandth of a degree. The Nansan bottles are numbered and represent various depths of the sea that have been tapped and measured. From 20 to 25 bottles spaced about 100 ft. apart on a cable are lowered into the sea from the current at one time with the aid of a winch. In some places, the sea floor is touched. An average survey depth is one mile, however. From information on temperature, salinity, surface and sub-surface currents collected from oceanographic research, the drift of icebergs may be predicted, and subsequently the most efficient use is made of the searching unit of the Ice Patrol.” NARA 26-G-5963