The Spatio-Temporal Patterns of Glacier Activities in the Eastern Pamir Plateau Investigated by Time Series Sub-Pixel Offsets From Sentinel-2 Optical Images

Abstract

The eastern Pamir Plateau, with a mean altitude of 5000 m, forms a large-scale glacier region with a size of 2054 km <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> that serves as an important environmental climate condition for central Asia. In this article, we estimated the spatio-temporal patterns of glacier activities in this region by using the time series sub-pixel offsets derived from 63 sentinel-2 optical images between December 31, 2020 and December 31, 2021. Our results indicated the mean glacier flow velocity in this region was 0.531 m/d ± 0.007 m/d in 2021, and the Kongur Tagh Glacier was much more active than the Kingata Glacier and Muztagh Ata Glacier. The time series observations revealed that the glacier motion involves a pre-melting period (January–April) with a velocity of 0.600 m/d ± 0.012 m/d, a melting period (May–August) with a velocity of 0.608 m/d ± 0.003 m/d, and a post-melting period (September–December) with a velocity of 0.659 m/d ± 0.006 m/d. In order to get insights into the characteristics of these glacier activities, we carried out a correlation analysis between the glacier flow velocity change and its potential caused reasons (i.e., topography, temperature, precipitation, glacier surges, debris-cover, and glacier thickness), and current results suggest that the glacier flow velocity is influenced by a combination of these factors.