Greenland Landslide Creates 650-Foot Tsunami That Shook Earth for Nine Days
Finn's Take· TL;DR- 25 million cubic yards of rock collapsed into Greenland's Dickson Fjord, creating a 650-foot tsunami that generated unprecedented 9-day seismic signals worldwide.
- Climate change weakened mountain structures in polar regions, increasing landslide risks near populated areas and cruise routes, demanding urgent monitoring systems.
- Satellite technology SWOT confirmed the event with exceptional detail, enabling scientists to reconstruct waves and develop early warning capabilities for Arctic regions.
A Mountain Collapses Into the Sea
On September 16, 2023, more than 25 million cubic yards of rock and ice – enough to fill 10,000 Olympic-size pools – broke loose and plunged into Dickson Fjord in eastern Greenland. The impact hurled up a mega-tsunami wave, reaching about 650 feet high , creating one of the most extraordinary geological events ever recorded.
Scientists eventually tracked the source to Dickson Fjord, a narrow channel in eastern Greenland walled in by cliffs that tower roughly 3,000 feet above the water . Fresh satellite images showed a new scar where a section of mountain had vanished . The massive landslide occurred in a region where climate change has been steadily weakening the ice and rock structures that hold steep mountain faces together.
The surge barreled down the two-mile corridor, bounced off the headland, and tore back again, wrecking roughly $200,000 in equipment at an empty research post on Ella Island . Fortunately, no people were present when the disaster struck, though Dickson Fjord sits near a popular cruise route .
Nine Days of Global Shaking
Water did not calm after the first pass. Instead, it began rocking from wall to wall, a motion known as a seiche . This rhythmic sloshing created something unprecedented in seismic records. The trace formed smooth peaks spaced a minute and a half apart and barely weakened over the better part of two weeks .
In September 2023, we detected the start of a 9-day-long, global 10.88-millihertz (92-second) monochromatic very-long-period (VLP) seismic signal, originating from East Greenland . No seiche had ever produced such a persistent global signature . The mysterious signal puzzled scientists worldwide until they traced it back to the Greenland fjord.
The mystery drew seventy-plus researchers from forty-one institutions. "When we set out on this scientific adventure, everybody was puzzled and no one had the faintest idea what caused this signal," said Kristian Svennevig of the Geological Survey of Denmark and Greenland .
Climate Change Connection
This event represents more than just a geological curiosity. The study's findings demonstrate the complex, cascading hazards posed by climate change in polar regions. While no people were in the area when the landslide and mega-tsunami occurred, the fjord is close to a route commonly used by cruise ships, highlighting the need to monitor polar regions as climate change accelerates .
The Dickson Fjord tsunami isn't an isolated incident. A landslide in western Greenland's Karrat Fjord in 2017 triggered a tsunami that flooded the village of Nuugaatsiaq, destroying 11 houses and killing four people . "As climate change continues to melt the Earth's polar regions, the number of large-scale landslides involving earth, rock, and ice that generate destructive events will multiply," says seismologist Alice Gabriel from the Scripps Institution of Oceanography .
Revolutionary Satellite Technology
The confirmation of this event marks a breakthrough in how scientists monitor remote disasters. The Surface Water and Ocean Topography (SWOT) mission launched in December 2022 maps a 30-mile-wide swath with 8-foot resolution , far superior to conventional satellites that can only see thin lines beneath spacecraft.
SWOT data taken above the fjord during the two mega-tsunamis revealed two cross-channel slopes moving in opposite directions between it, confirming their presence. Seismic observations made thousands of miles away, alongside weather and tidal readings, further enabled the researchers to reconstruct the waves and conclusively link them to the mysterious seismic signals .
This technological advancement opens new possibilities for understanding extreme oceanic events. Better forecasts could one day provide critical minutes of advance warning for ships and settlements in high-latitude waters . As Arctic regions become increasingly accessible and climate change accelerates geological instability, such early warning systems may prove essential for protecting lives and property in these remote but increasingly visited areas.