Recent Variation of the Malan Glacier in Hoh Xil Region of the Tibetan Plateau
PU Jian-chen, YAO Tan-dong, WANG Ning-lian, DING Liang-fu, ZHANG Qi-hua (Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou Gansu 730000, China)
Located in Hoh Xil Region in the center of the Tibetan Plateau, Malan Glacier is a large extreme continental glacier, with a total area of 195 km 2. Its equilibrium line altitude varies from 5 430 to 5 540 m. There are three moraines of the Little Ice Age in front of glacier tongue. The glacier tongue was 20 m lower on the southern slope and 20～40 m lower on the northern slope in the Little Ice Age than that at present. Since the Little Ice Age the glacier has reduced its area accounting for 4.6% of the present area, while this ratio is near 8% in the Qangtan Region, Tibetan Plateau. In the past about 100 years, the glacier retreated 45～60 m, and in the recent 30 years from 1970, the Malan Glacier retreated 30～50 m, with a ratio of 1～1.7 m·a -1. Though the retreating is less than that in the surrounding areas of the plateau, the retreating ratio is increasing, which might have a significant effect on the vulnerable ecosystem on the plateau.