Thwaites Glacier

Thwaites carries ice from the interior of West Antarctica toward the Amundsen Sea. Much of its bed lies below sea level, allowing ocean water to reach beneath the ice.

The critical boundary is hidden: the grounding line where ice leaves the bedrock and begins to float. Channels, ridges and sediment on the seafloor influence how retreat unfolds.

Thwaites is closely watched because it helps restrain inland ice. Its future is a long-term sea-level question, not a prediction of sudden overnight collapse.