Abstract:

The Pamir Plateau in Central Asia (30°00′-41°00′N; 73°00′-77°30′E) includes parts of Afghanistan, Tajikistan, and China. The Chinese part is known as the eastern Pamir, located in southwestern Xinjiang. The Sino-Pakistan Highway passes through the study area. Glacier meltwater nourishes the people of Kashi Prefecture, Xinjiang, China. Pamir glaciers have recently shown unusual behavior: On average, no significant area and mass changes but frequent advances and surge activities have been observed during the last decades. The characteristics of glacier movement are helpful in understanding the unusual behavior. In our study, glacier movements at a different scale, topography, and morphology were analyzed by the Inter-Mission Time Series of Land Ice Velocity and Elevation and Global Land Ice Velocity Extraction from Landsat 8 data. The results are as follows: (1) The average glacier velocity in the eastern Pamir is 5.31 m·a^-1 and is related to glacier scale, which shows that large glaciers move faster than small glaciers. (2) Glacier velocity is related to the average slope, which first increases and then decreases with the increase of the average slope. Excessive slopes are not conducive to glacier accumulation, and because the thickness (scale) is small, velocity is slow. (3) Glacier velocities on southwestern (8.69 m·a^-1) and southeastern (11.67 m·a^-1) slope directions are greater than those of other slope directions, which is related to the scale of glaciers in each slope direction. (4) Debris-covered glacier velocity is lower than that of debris-free glaciers because debris inhibits movement. (5) Glacier velocities were stable from 1985 to 2018, which is consistent with the stable area and mass trends of the eastern Pamir glaciers. Glacier velocities in melting seasons were lower than those in the pre-melt and post-melt seasons, which is presumably related to annual thickness changes.

Key words: eastern Pamir Plateau, glacier movment, glacier moving characteristics, remote sensing, terrain