Identifing the debris-covered terminus for the Middle-West Rongbuk Glacier at the Mt. Everest in the Central Himalayas

Debris-covered glaciers have been widely recognized in glacier runoff contributions and ice-rock disasters. It showed that debris-covered glaciers occupy about 27% glacierized region in the Central Himalayas. However, the delineation of debris-covered glaciers is still the bottleneck, which leads to high uncertainties in glacier change deteriorating our understanding of the hazard cascade from the collapse of rock and ice. Therefore, it is vital to provide the definitive margins of the debris-covered ice.

Here, we put forward a suitable method to locate the debris-covered glacier terminus of the Middle-West Rongbuk glacier based on multi-temporal surface elevation change data pairs from multi-source remote sensing data (such as DEM differencing, ICESat-2 laser altimetry, and InSAR technology). According to the DDh indicator (the difference in Dh), the debris-covered glacier terminus is determined. In addition, the glacial movement velocity generated from Sentinel-1 images was also used to verify the determined terminus outline of the debris-covered glacier. Our results showed that, from 1974 to 2025, the terminus of the debris-covered Rongbuk Glacier continuously migrated to higher elevations, rising from about 5240±20 m in the 1970s to 5290±20 m in the 2000s, then upward further to 5400±50 m after the 2010s. Over the past 48 years, the cumulative upward shift was approximately 160 m.