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 an...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.展开更多
Many glaciers and ice caps on the Tibetan Plateau have retreated and lost mass in recent years in response to temperature increases,providing clear evidence of the impact of climate change on the region.There is incre...Many glaciers and ice caps on the Tibetan Plateau have retreated and lost mass in recent years in response to temperature increases,providing clear evidence of the impact of climate change on the region.There is increasing evidence that many of the glaciers on the Tibetan Plateau have also shown periodically dynamic behaviour in the form of glacier surging and some even catastrophic collapse events.In this study,we examine the prevalence of glacier surging at the Geladandong ice caps,North East Tibetan Plateau,to better understand the role of surge events in the evolution of glacier mass loss budgets.Using glacier surface elevation change data over the period 1969—2018 and glacier surface velocity data from the ITS_LIVE dataset,we find that 19 outlet glaciers of the ice caps are of surge-type.Our multi-temporal measurements of glacier mass balance show that surge-type glacier mass budgets vary depending on the portion of the surge-cycle captured by geodetic data.At the regional level,pre-and post-surge glacier mass loss variability does not bias regional mass budget estimates,but enhanced,or suppressed,mass loss estimates are likely when small groups of glaciers are examined.Our results emphasise the importance of accurate surge-type glacier inventories and the need to maximise geodetic data coverage over glacierised regions known to contain surge-type glaciers.展开更多
基金The Second Tibetan Plateau Scientific Expedition and Research Program,No.2019QZKK020102National Natural Science Foundation of China,No.42130516。
文摘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.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA20100300).
文摘Many glaciers and ice caps on the Tibetan Plateau have retreated and lost mass in recent years in response to temperature increases,providing clear evidence of the impact of climate change on the region.There is increasing evidence that many of the glaciers on the Tibetan Plateau have also shown periodically dynamic behaviour in the form of glacier surging and some even catastrophic collapse events.In this study,we examine the prevalence of glacier surging at the Geladandong ice caps,North East Tibetan Plateau,to better understand the role of surge events in the evolution of glacier mass loss budgets.Using glacier surface elevation change data over the period 1969—2018 and glacier surface velocity data from the ITS_LIVE dataset,we find that 19 outlet glaciers of the ice caps are of surge-type.Our multi-temporal measurements of glacier mass balance show that surge-type glacier mass budgets vary depending on the portion of the surge-cycle captured by geodetic data.At the regional level,pre-and post-surge glacier mass loss variability does not bias regional mass budget estimates,but enhanced,or suppressed,mass loss estimates are likely when small groups of glaciers are examined.Our results emphasise the importance of accurate surge-type glacier inventories and the need to maximise geodetic data coverage over glacierised regions known to contain surge-type glaciers.
