乔戈里峰北坡现代冰川的初步观察

The Characterisitcs of the Present Glaciers on the Northern Slope of Mt. Qiaogeli

乔戈里峰北坡有现代冰川69条,总面积815.9km^2。其中大型冰川4条,面积709.06km^2。受西南季风影响,积累区物质来源丰富,消融区冰面地形复杂,差别消融强烈。冰川运动速度较高,冰川温度上段较低,下段较高。冰川类型应为暖季补给为主的亚大陆性冰川。

The studing region on the Northern Slope of Mt. Qiaogeli is one of the centres of existing glaciers in the mountains of the mid-latitude, where 69 glaciers existing and the total glacial area is 815.91 km2,in which 709.06 km2area is occupied by the four largest glaciers (sikanyang Glacier, Qiaogeli Glacier, Musitage Glacier and Yinsugaiti Glacier). The investigations and measurements show that the high elevation of the region supllies the condition of low temperature to glacier is mostly precipitation caused by the Southwest Monsoon from India Ocean. Combining with the landscape factor of the topography highest mountain area, the avalanche also is a important source of the accumulation. According to hte measurements of snow pits in Qiaogeli Glacier and the comparison with the previous studes,the estimated accumulation rate in the higher mountain area is much more than 1000 mm / a, and the estimated ablation rate of ablation area is about 1-2 m or to several metres in' amount. The distribution of the formation zones from upper to the end of Qiaogeli Glacier is sequential the small cold-infiltration zone the infiltration zone,the large infiltration-congelation zone (superimposed ice zone) and ablation zone. The equilibrium line in 1986 was between 5700-5900 m. The Qiaogeli Glacier is a complex-valley type glacier. It consists of the five west firn basins and ice falls in west side, the main firn basin, the west firn basin and a long tongue. There are pyramids on the surface of the upper and the middle parts of the tongue, and the lower part of the tongue is covered by superglacial moraine. The lands cape of the surface on the four largest glaciers is as similar as Qiaogeli Glacier. The measured flow velocity of Qiaogeli Glacier shows that the highest part of the flow velocity is in the middle of the tongue, about 40 m / a, the flow velocity starts to reduce upward and down from this part, and the flow velocity is just 6 m / a near the endof the tongue. The temperature measurements in the 10 m deep ice are -6℃ at 5300 m and 0℃ at 4400 m Respectively. Based on the mentioned characteristics, the glaciers in our studing region belong to sub-continent type glacier replenished in warm season only, their features are similar to glaciers on the Northern Slope of Mt. Zhumulangma.