Area, volume and ELA changes of West Greenland local glaciers and ice caps over the last 35 years

The behaviour of mountain glaciers on decadal time scales is a useful indicator for assessing climate change. Although less monitored and studied than the ice sheet, local glaciers and ice caps (GICs) along the coast of Greenland are significant contributors to meltwater runoff and sea level rise. This study analyses the cumulative area, ice mass and ELA changes occurred in 4100 GICs in West Greenland from 1985 to 2020, using remotely sensed data and including smaller glaciers in the calculations. GICs involved in the study decreased in area by almost 15%, which is equal to -1774 ± 201 km². Their surface elevation decreased on average by 20.6 ± 2.9 m, corresponding to a rate of -0.5 m w.e. yr^-1. The Equilibrium Line Altitude (ELA) shows a median regional rise of 150 m since the 1980’s with marked local variability and higher median rise in the northern areas of this study. Strong regional gradients in ELA of individual GICs are found, both towards the ice sheet and in areas where local orography affects precipitation. The observed high spatial variability of changes suggests that more monitoring on sub-regional level is needed to reduce uncertainty regarding the future of GICs. This study on West Greenland Local Glaciers and Ice Caps underscores their diverse nature in terms of glacier type, size, aspect, and hypsometry. Measurements show high variability in the net changes from 1985, including area and volume shrinkage, alongside an elevation rise of ELAs. We observe a nearly 15% reduction in overall glaciated area, accompanied by a mass balance rate of -0.5 m w.e. yr-1 (- 5.6 ± 0.7 Gt yr-1), aligning with observed rates in the Arctic.