The Sub-Country

Up-glacier propagation of surface lowering of Yala Glacier, Langtang Valley, Nepal Himalaya

“…a −1 for the 2011-2017 period), whereas the estimate by Brun and others (2017) is less negative than these values. The difference among our 1981-2007 B g and those of previous studies is likely due to the DEM accuracies, as the two DEMs, which are based on a 1981 map in this study and a KH-9 Hexagon image in the previous studies (Ragettli and others, 2016;Maurer and others, 2019), may contain errors. The 1981 map was derived from ground photogrammetry using base points that were horizontally 2 km from the glacier terminus, thereby suggesting a lower accuracy over the up-glacier part (∼5600 m) of the glacier due to the relatively large distance between the base points and the snow-covered area.…”

“…Sugiyama and others, 2013;Ragettli and others, 2016;Stumm and others, 2021) and/or the glaciers across the region (e.g. Maurer and others, 2019). Furthermore, the estimated B g for the 2007-2015 period was more negative than both the regional mean geodetic mass balances for central Nepal (−0.46 ± 0.12 m w.e.…”

“…a −1 ) and debris-free glaciers in the Himalaya (−0.38 ± 0.08 m w.e. a −1 ) during the 2000-2016 period (Maurer and others, 2019). Small debris-free glaciers that are located at relatively lower elevations in the Himalaya have exhibited similar large mass loss trends in recent years (e.g.…”

“…Note that the values fromMaurer and others (2019) and Brun and others (2017) were calculated using the hypsometry in this study and the 50 m binned mean elevation changes from their respective studies.…”

“…a −1 , each with a maximum uncertainty of 0.09 m w.e. a −1 , for the1981-1996 and 1996-2009 periods, respectively, using much of the same data that were used in this study Maurer and others (2019). estimated the elevation differences along glaciers throughout the Himalaya via an analysis of declassified KH-9 Hexagon satellite and ASTER images (Fig.S6).…”