第九届青年地学论坛

The western Kunlun main peak region is among the areas in High Mountain Asia where surge-type glaciers are highly concentrated, garnering substantial attention from glaciologists. Previous research has predominantly focused on remote sensing surveys and surge characteristic analyses in this region, with limited focus on analysing the controlling mechanisms behind glacier surges, particularly in understanding the asynchronous behaviours among neighbouring surging glaciers. Here, we analyse the surging characteristics of the eastern and western branches of the Western Kunlun Glacier and the factors controlling the asynchronous behaviour of their surges. The eastern branch entered an unstable state in 1999 and remained so until the culmination of its surge in the summer of 2019, spanning 21 years and exhibiting similarities with the characteristics of Svalbard-type surge-type glaciers. Conversely, the surge of the western branch commenced in the summer of 2020. Upon merging with the eastern branch glacier, the glacier’s surface velocity gradually returned to presurge levels. The surge duration for this glacier was four years, characterized by a rapid acceleration and deceleration process, similar to the characteristics of Alaskan-type surge-type glaciers governed by hydrological mechanisms. Furthermore, the increase in solid precipitation in the glacier region, driven by climate change, likely resulted in glacial thickening, leading to an uneven spatial distribution of basal shear stress and exacerbating glacier instability. This process intensifies crevasse formation on the glacial surface, providing conduits for surface meltwater to reach the glacier bed, thus elevating subglacial water pressure. Simultaneously, the marked differences in the subglacial topography and mass accumulation rates between the eastern and western branches are fundamental factors controlling the asynchronous surging behaviours of these glaciers. This study provides a remote sensing perspective for interpreting the asynchronous behaviours of glacier surges without field observations of englacial/subglacial processes.
 

Mechanism of glacier surge, Changes in glacier surface elevation, Glacier velocity, Western Kunlun, Remote sensing