In September 2023, seismometers across the globe began picking up a signal no one recognised. It arrived every 90 seconds, like a slow mechanical pulse, and it continued for nine days. Then, roughly a month later, it happened again. The recordings looked nothing like an earthquake: no broadband rumble, no frequency-rich overtones, just a single, [...] The post In September 2023 a mega-tsunami in Greenland sent tremors around the entire planet for nine days and scientists have only just confirmed