A preliminary report on some limnological investigations of lakes in the vicinity of Syowa Station by Japanese Antarctic Research Expedition in 1981 and 1985

Abstract

The characteristics of vertical water temperature distributions of several lakes which have been studied as part of the "monitoring of the environmental change project" in the Lutzow-Holm Bay region are preliminarily reported, based mainly on the results obtained by the 26th Japanese Antarctic Research Expedition (JARE-26) in 1985/1986 and in part by JARE-22 in 1981,together with some other data. Selected lakes consist of saline and freshwater ones. Each saline lake has its characteristic temperature distributions, and seems to have two-layer structure which consists of the upper layer undergoing large seasonal fluctuations and the lower layer having rather stable temperature distributions. This structure corresponds to remarkable chemical stratification. The pattern of temperature distribution of each lake seems to have differed little for considerable years, but the absolute temperature value changes slightly from year to year. Freshwater lakes show typical inverse stratification when lakes are covered with an ice layer in winter, and fluctuation from year to year is very small. In addition, general features of two newly investigated lakes are reported. They are situated in ice-free areas in the southern part of the eastern coast of Lutzow-Holm Bay, adjoining the ice sheet. Their waters show very low concentration of dissolved salts.