Abstract 
The use of stations on drifting pack ice for geophysical and 
oceanographic studies of the Arctic Ocean proved highly successful. The 
investigations by Lamont Geological Observatory from Drifting Stations 
Alpha, Bravo and Charlie provided new information about the environment 
of the Arctic Oceane A prominent topographic feature, the Alpha Rise, was 
delineated and mapped from Station Alpha. The floor of the Arctic Ocean 
was observed directly for the first time in submarine bottom photographs. 
Unique deposits of gravel were found on the ocean floor and found to have 
been ice-rafted from a glacial shore area. Acoustic wave propagation in 
the ice revealed large seasonal changes in velocity. The Chukchi Rise 
was delineated in detail with fathograms produced by a precision depth 
recorder on Station Charlie. Long range deep-water underwater sound 
transmission was also observed from this station and the results interpreted 
in terms of normal mode theory. Finally, at Station Bravo, shallow-water 
underwater sound transmission was observed and found to agree with theory 
for normal modes propagating in an ice-water=-sediment system. 
