MASS BALANCE STUDIES ON THE NO.1 GLACIER OF RMGI RIVER IN TIANSHAN
Zhang Jinhua (Lanzhou Institute of Glaciology and Cr yopedology, Academia Sinica)
In this paper, the seven year-round ( from 1959 to 1967 ) observed data of mass balance on No.1 Glacier and the climatic data of the Tianshan meteorological station located at an elevation of 3,546 m approximately 2.5km from the No.l Glacier' were used, and their correlations investigated. Based on the above mentioned analysis, the location of snowline (ELA) and mass balance were calculated and these data were prolonged to sixteen years by extrapolation. Then, the author discussed the regularity of the changes and their characteritics. The following points may be drawn by statistical analysis: ( 1 )the mean height of zero equilibrium line (ELA) for many years is 4,050m, ( 2 )when the annual precipitation on the glacier is estmated to be over 450 mm,the mass balance has positive values and a small regular fluctuation appears at every two or three years interval, ( 3 Muring the sixteen years of negative,variational tendency of mass balance there appeared four times of positive . values. However, these negative values are far less than those in other mountains of middle latitude, and( 4 )the annual mean reduction of glacial thickness is 0.084 m, and the annual mean recession is 5.12m in 1962-1973. On the basis of the above-mentioned facts, the author considers that the No.l glacier of Urumgi river is a comparatively stable mountain glacier in China.