Abrupt drainage of Lago Greve, a large proglacial lake in Chilean Patagonia, observed by satellite in 2020

Abstract Glacial lakes are increasing in number and extent under a warming climate. Despite demand for lake monitoring understanding outburst mechanisms, studies of large events sparse. Here we report an Lago Greve, proglacial Chilean Patagonia. During the event April–July 2020, level dropped by 18.3 ± 1.2 m area decreased 14.5 0.02 km 2 . The total water discharge was 3.7 0.2 3 , which is one largest glacial outbursts ever reported satellite era. Satellite data indicated collapse bump near outlet triggered event, initiating erosion bank bed stream. gravimetry captured signal although magnitude corresponding mass change inconsistent with drained mass. Our study demonstrated potential observing using imagery, altimetry, photogrammetry, gravimetry.