It started with a melting glacier, which set off a landslide, which triggered a 650-foot high mega-tsunami in Greenland. Then came something inexplicable.

We were baffled—the signal was unlike any previously recorded. Instead of the frequency-rich rumble typical of earthquakes, this was a monotonous hum, containing only a single vibration frequency. Even more puzzling was that the signal kept going for nine days.

A colossal rockslide that triggered a mega-tsunami caused the Earth to ‘hum’ for days, an event scientists say is directly linked to climate crisis