![]() Approximately 11% of this glacier area and 18% of the corresponding glacier volume is debris-covered ( Kraaijenbrink et al., 2017 Scherler et al., 2018). The Randolph Glacier Inventory (RGI v6.0 RGI Consortium, 2017) includes 95,536 glaciers over HMA (regions 13, 14, and 15), covering an area of ~97,605 ± 7,935 km 2 (assuming ~8% uncertainty Pfeffer et al., 2014). High-mountain Asia (HMA), which comprises the Tibetan Plateau and its surrounding mountain ranges (including the Himalaya, Karakoram, Tien Shan, and Pamir) contains the largest concentration of glacier ice outside of the polar regions, earning it the informal title of “The Third Pole” ( Vaughn et al., 2014). Glaciers and ice caps contributed ~21% of total global SLE rise from 1993 to 2018 ( WCRP Global Sea Level Budget Group, 2018), roughly equivalent to the combined contribution from the Antarctic and Greenland ice sheets during this period. Worldwide, glaciers, and ice caps are losing mass, with an estimated 0.71 ± 0.08 mm yr −1 sea level equivalent (SLE) contribution from 2003 to 2009 ( Gardner et al., 2013), 0.92 ± 0.39 mm yr −1 from 2006 to 2016 ( Zemp et al., 2019), and 1.85 ± 0.13 mm yr −1 from 2012 to 2016 ( Bamber et al., 2018). They constitute important seasonal and long-term hydrologic reservoirs, providing water for hydropower, agriculture, and municipal use ( Guido et al., 2016 Ragettli et al., 2016 Milner et al., 2017 Pritchard, 2019) Glaciers can also be a significant natural hazard, especially for regions subject to catastrophic glacier outburst floods ( Harrison et al., 2017 Haritashya et al., 2018 Allen et al., 2019). Glaciers are sensitive climate indicators that primarily respond to interannual changes in temperature and precipitation (e.g., Bertrand et al., 2012 Harrison, 2013). These results can be used for calibration and validation of glacier mass balance models, satellite gravimetry observations, and hydrologic models needed for present and future water resource management. We estimate that the range of excess glacier meltwater runoff due to negative glacier mass balance in each basin constitutes ~12–53% of the total basin-specific glacier meltwater runoff. ![]() Our results offer improved estimates for the HMA contribution to global sea level rise in recent decades with total cumulative sea-level rise contribution of ~0.7 mm from exorheic basins between 20. We document the spatial pattern of HMA glacier mass change with unprecedented detail, and present aggregated estimates for HMA glacierized sub-regions and hydrologic basins. We estimate total HMA glacier mass change of −19.0 ± 2.5 Gt yr −1 (−0.19 ± 0.03 m w.e. We combined these observations to generate robust elevation change trend maps and geodetic mass balance estimates for 99% of HMA glaciers between 20. We also reprocessed 28,278 ASTER DEMs over HMA from 2000 to 2018. To address these issues, we generated 5,797 high-resolution digital elevation models (DEMs) from available sub-meter commercial stereo imagery (DigitalGlobe WorldView-1/2/3 and GeoEye-1) acquired over HMA glaciers from 2007 to 2018 (primarily 2013–2017). Recent satellite data capture the spatial variability of this mass loss, but spatial resolution is coarse and some estimates for regional and HMA-wide mass loss disagree. Although available observations are limited, long-term records indicate sustained HMA glacier mass loss since ~1850, with accelerated loss in recent decades. ![]() High-mountain Asia (HMA) constitutes the largest glacierized region outside of the Earth's polar regions.
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