In September 2023, scientists monitoring seismic activities worldwide detected an unusual signal. This signal, distinct from the typical earthquake rumble, resonated as a continuous hum, maintaining a singular frequency. For nine consecutive days, this hum echoed across the globe, spanning from the Arctic to Antarctica, leaving researchers baffled. Initially classified as a “USO” — an unidentified seismic object — the source of the signal was eventually identified. A colossal landslide in Greenland‘s Dickson Fjord was responsible for the mysterious hum. The event involved a massive amount of rock and ice, enough to fill approximately 10,000 Olympic-sized swimming pools, plummeting into the fjord. This caused a mega-tsunami, with waves towering up to 200 metres, double the height of London’s iconic Big Ben.

The Landslide’s Source

The landslide was directly linked to the ongoing effects of climate change. Due to the thinning of a nearby glacier, the fjord’s stability had been compromised. The glacier had lost tens of metres in thickness over decades, leading to a weakened structure. When the mountain finally gave way, the sheer force of the collapse generated seismic waves that reverberated around the planet.

Implications of the Event

In their study published in Science, the research team noted that the signal was created by standing waves within the fjord caused by the rockslide. These findings underscore the cascading and hazardous feedback loops between the Earth’s ice, water, and land systems as the climate continues to warm.

As global temperatures rise, landslides, tsunamis, and similar events in polar regions could become more frequent.