Characterizing the behavior of surge-type glaciers in the Puruogangri Ice Field, Tibetan Plateau

The Puruogangri Ice Field (PIF), classified as an ultra-continental glacier, is considered extremely stable. However, several glaciers in this area have recently experienced surge events with significant instability and information on surge-type glaciers (STGs) in this region remains scarce. In this study, we identified six STGs and reported the observed characteristics of their surging behavior in the region by mapping glacier boundaries, surface flow velocity information, and glacier surface elevation changes using recent Landsat satellite imagery and shuttle radar topography mission (SRTM), TanDEM, and ASTER digital elevation model (AST14DEM) data. These data provide valuable insights into recent glacial processes, flow instability, and rapid glacial movement. During the active phase of the glaciers, all exhibited frontal advances and changes in surface elevation. Owing to limitations in the satellite imagery, flow velocity profiles were only available for glaciers N1 (G089071E33998N), NE1(G089128E33943N), and SE3 (G089278E33913N) during the active phase. However, these results effectively reflect the velocity variations in both glaciers before, during, and after the surge. Based on the characteristics of the STG, scientific expeditions, and meteorological data, we believe that the surge in PIF was largely influenced by glacier meltwater and changes in subglacial drainage systems.