Mega-Tsunami in Greenland's Dickson Fjord Reveals Hidden Climate Change Dangers

In September 2023, seismometers worldwide detected an unusual, persistent signal occurring every 90 seconds over a nine-day period. This enigmatic seismic activity, initially classified as an "unidentified seismic object," puzzled scientists until investigations traced its origin to a remote fjord in East Greenland. There, a massive landslide had triggered a mega-tsunami, setting off a series of events that underscored the profound impact of climate change on Earth's geological processes.

On September 16, 2023, a 1,200-meter-high mountain peak in Dickson Fjord collapsed, releasing approximately 25 million cubic meters of rock and ice—equivalent to 10,000 Olympic-sized swimming pools—into the fjord below. This colossal landslide generated an initial wave towering up to 200 meters, one of the highest tsunamis recorded in recent history. The force of the wave was so immense that it caused significant damage to the Ella Ø research base, located 70 kilometers away, where waves reached heights of four meters.

The fjord's unique topography trapped the tsunami energy, leading to the formation of standing waves, known as seiches, which oscillated within the fjord. These seiches produced the persistent seismic signals detected globally. A study published on June 3, 2025, in Nature Communications by researchers from the University of Oxford provided the first direct observations of these seiches. Utilizing data from the Surface Water and Ocean Topography (SWOT) satellite, the team mapped water surface elevations in the fjord, confirming the presence of oscillating waves with height differences up to two meters. This research validates the seiche theory and highlights the potential of advanced satellite altimetry in studying extreme climate-induced events.

This event underscores the complex interplay between climate change and geological phenomena. The thinning of glaciers due to rising global temperatures can destabilize mountainous regions, increasing the likelihood of landslides and subsequent tsunamis. The Dickson Fjord incident serves as a stark reminder of the cascading effects climate change can have on Earth's systems. The persistent seismic signals generated by the seiches highlight the need for comprehensive monitoring of remote regions to better understand and predict such events. The successful use of advanced satellite altimetry in this study demonstrates the potential of new technologies in observing and analyzing extreme climate-induced events.

While landslide-induced tsunamis are not unprecedented, the Dickson Fjord event is notable for its magnitude and the prolonged global seismic signal it generated. Similar events have occurred in Greenland, but none have produced such a persistent and detectable seismic signature. This incident provides valuable data for understanding the dynamics of seiches and their potential to generate long-lasting seismic signals.

The Dickson Fjord landslide and subsequent seiches provide a compelling example of the far-reaching impacts of climate change on Earth's geological processes. This event highlights the importance of integrating advanced technologies and international collaboration in monitoring and understanding such phenomena.