Antarctica robot sub uncovers hidden melt features before vanishing

An autonomous submarine named Ran mapped the underside of West Antarctica's Dotson Ice Shelf, revealing terraces, channels and teardrop pits carved by basal melt, before losing contact and disappearing after traveling roughly ten miles beneath the ice for about 24 hours; the data improve understanding of how warm deep water melts ice from below and influence future sea-level predictions, but the cause of Ran's disappearance remains unknown.