Holes the size of city blocks are forming in the Arctic seafloor
Excerpt: Marine scientists have discovered deep sinkholes -- 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. Mapping of Canada's Beaufort Sea, using a remotely operated underwater vehicle and ship-mounted sonar, revealed the dramatic changes, which the researchers said are taking place as a result of thawing permafrost submerged underneath the seabed. ...On land, thawing permafrost has led to radical shifts in the Arctic landscape, including ground collapses, the formation and disappearance of lakes, the emergence of mounds called pingos, and craters formed by blowouts of methane gas contained in the permafrost. These extreme features have affected infrastructure such as roads and pipelines. ...Many of the landscape changes seen on terrestrial permafrost have been attributed to warmer temperatures as a result of the climate crisis -- the Arctic is warming two times faster than the global average. However, the authors said the changes they'd identified could not be explained by human-caused climate change. ...Instead, the holes were likely caused by much older, slower climatic shifts that are related, he said, to our emergence from the last ice age and appear to have been happening for thousands of years.…