CTD casts off Pram Point to determine the internal wave structure under the shore fast ice of McMurdo Sound

The internal wave structure under the shore fast ice of McMurdo Sound was surveyed. An internal wave is a wave propagating along a density stratification in the water mass. The discontinuity in density is caused by a difference in the temperature or salinity on either side of the boundary surface in the water mass. Previous studies conducted either single CTD profiles or spot temperature and salinity measurement using sample bottles and reversing thermometers. These methods lack the regular time scale necessary for determining internal wave structure. By carrying out monitoring of the water column it was hoped to find internal waves missed by earlier oceanographic surveys of McMurdo Sound. 46 CTD casts were taken from two locations near Scott Base, in McMurdo Sound. Two series of casts were taken, the first consisted of three days when casts were taken on an approximately hourly basis, and the other contained data taken over thirteen days.