Lago Viedma is a proglacial lake into which the Viedma Glacier flows from the Southern Patagonian Ice Field. This glacier has rapidly lost mass in recent times, and its deglacial history is reflected in the lake's subsurface. New high‐resolution multi‐channel seismic profiles acquired in the northwestern sector of the lake have allowed us to reconstruct the bathymetry of the area and identify several small sub‐basins, which ha...