These two Sentinel-2
images show changes over 4.5 years at a portion of Quelccaya's
western margin. The view includes Lonnie Thompson's Base Camp
(lower left) for fieldwork since the 1970s, and the marginal lake
we refer to as Morojanicocha.
Some visible differences are seasonal, such as the higher water levels in May and lower-albedo ice in the ablation zone during November (also with less snowcover).
Most notable is ongoing retreat of the ice margin, particularly towards the bottom of the image where the ice is thinner. Ice is no longer calving into the lake, and our colleague Gustavo Valdivia reports that it is now possible to walk entirely around it on rock.