Wikipedia
Dead-ice
Dead-ice occurs when a glacier or ice sheet ceases to move and melts in situ. After the ice has melted it leaves behind a hummocky terrain produced by the deposition of glacio-fluvial sediments and ablation till as the ice melted. Such features include kettle holes. Landscape forming Veiki moraines in northern Sweden and Canada have been ascribed as the result of ablation of extensive bodies of till-covered dead-ice.