Comparison Study of Glacier Variations in East and West Tianshan Mountains

The glaciers in Tianshan Mountains are retreating.But the retreating rate is quite different between East and West Tianshan Mountains.The Glacier No.1 at the headwaters of urumqi River is taken as a representative glacier for East Tianshan Mountains,and the Glacier Tuyuksu is taken as a representative glacier for West Tianshan Mountains.The mean net mass balance is-235 mm and-409 mm,the mean glacier terminal variation rate is-0.0018·a-1 and-0.0047·a-1,the mean rate of glacierized area variation is-0.0029·a-1 and-0.0046·a-1,respectively,for the East and West Tianshan Mountains.While glacierized area variation rate in larger regions is-0.0018·a-1 and-0.0072·a-1,respectively,during the last 40 years.The climate patterns of East and West Tianshan Mountains are similar while precipitation decreases from west to east.This results in that the large glacier retreating mainly due to the rising of summer temperature in the whole mountains.However,the great difference in variation rate between East and West Tiashan Mountains can be explained by the difference of glacier mass balance lever and the glacier stability coefficient.For Glacier No.1 and Glacier Tuyuksu,the glacier mass balance lever and the glacier stability coefficient are 633 mm,1180 mm and 0.514,0.326,respectively.The result indicates that the higher mass balance level and smaller glacier stability coefficient,the more sensitive to climate change.