The objective of this research is to document the summer salinity and temperature variability and to identify the processes responsible for the growth of pack ice floes and fast ice. Ice cores were obtained from the pack ice of the Ross, Amundsen and Bellingshausen seas, and the fast ice of McMurdo Sound in austral summers 1991-92 and 1992-93 during cruises aboard the U.S. Coast Guard icebreaker USCGC Polar Sea. Analysis of crystal structure reveals that pack ice growth is dominated by frazil ice generation in the turbulent Southern Ocean environment. The stable isotopic composition of pack ice floes shows that seawater flooding of the surface of floes and subsequent formation of snow ice is common. Congelation ice and platelet ice are the primary contributors to the development of the fast ice in McMurdo Sound. The small-scale variability of salinity, temperature, brine volume, crystal structure, brine layer spacing and crystal c-axis orientation in McMurdo Sound fast ice was the subject of M.S. thesis research by Alice Veazey.

NSF Grant OPP89-15863: Scientific personnel; M. O. Jeffries, W. F. Weeks, A. L. Veazey, K. Morris, H. R. Krouse (University of Calgary).