Desarrollo de la Antártica

Víctor T. Neal / INTERNATIONAL SOUTHERN OCEAN STUDIES Victor T. Neal (Sohool of Oceanography, Oregon State University, 1C0rvaUis, Oregon 97331). The first field expeditian was originaIly scheduled for 1975. Logistic support, however, became available for a trial study in September, 1974. In this study measurements were planned between !M:cMurdo iStation and Mal'ble Point. iAlthough McMurdo Sound ex:perienced one of its heaviest ice years, a series of h1gh winds in late August produced some ice break out. Therefore, measurements were made only near the ice sheH. A team of four spent about four weeks on the ice. Hydrograp'hic casts, continuous vertical temperature profiles (from the ice to bot– tom depths of ahout 1500 m), and time series of temperature at fixed depths were obtained at three stations. [n addition a vertical profiling current meter was used to obtain profiles as well as time series measurements at fixed depths. 'Ilhis field expedition demonstrated the feasibility of obtaining useful high resolution measurements tllrough the winter sea ice in the Antarctic. The next field program planned for August-September 1975 and subsequent field programs were canceIled because 10gistical support was not available. FDRAKE 7,5 The first major ISOS field program, FDRAKE (First Dynamic Response and Kinematic Experiment), was carried out during January-March 1975 in the Drake Passage and western Scotia ¡Sea. Three ships were involved in the program: Rfv OONRAD and Rfv MEINILLE of the USA, and ARA ISLAS aRCADAS of Argentina. Chief scientist lOro Kilho Park (School of Oceanography, Oregon State Universíty, Corvallis, Oregon 91331, USA) and scientists from University of Washington, Texas A.I/cM University, Instituto Antár– tico Argentino, Oregon State University, and Universidad Católica de Valparaíso (Chile) were at sea fromIO January to 3 March on board ARA ISLAS aRCADAS studying the physical and chemical properties of the regíon. Thermohaline and nutrient distributions were measured across DrakePassage and in the western Scotia Sea. A total of 85 STO (salinity-temperature-depth) profiles and 34 water sampling bot– tle stations were completed. Surface tf;mperature and ocean depth were recorded continuously along the cruise track while XBT's (expendable bathythermograplls) were used between stations. Water samp]es were processed aboard ship to obtain salinity, oxygen,