Giant sinkholes in Arctic seafloor observed for the first time – CNN

Marine scientists have discovered deep sinkholes — including one larger than a city block of six-story buildings — and ice-filled hills that have formed “extraordinarily” rapidly on a remote part of the Arctic seafloor.
— Read on www.cnn.com/2022/03/14/world/arctic-seafloor-holes-permafrost-scn/index.html