Greenland Landslide Triggered Global ‘Crustal Heartbeat’ – Mega-Tsunami Explained

For years, the remote eastern coast of Greenland remained a region of geological quiet. Then, in mid-September 2023, seismic sensors worldwide began registering an unusual, persistent signal – a slow, rhythmic pulse that continued for nine consecutive days. This wasn’t the sharp, chaotic signature of a typical earthquake. Instead, the signal presented as a steady beat, occurring every 92 seconds, powerful enough to vibrate bedrock across vast distances, from Alaska to Australia, yet imperceptible to humans on the surface.

The source of this prolonged seismic event was eventually pinpointed to Dickson Fjord, a narrow, steep-walled channel in eastern Greenland. Satellite imagery revealed a significant change: a section of the mountainside had collapsed, leaving a visible scar. This landslide triggered a colossal event, setting the fjord into motion and sending out waves of energy that reverberated around the globe.

Mountain Falls, Dickson Fjord Rises

On September 16, 2023, approximately 25 million cubic yards of rock and ice – a volume equivalent to 10,000 Olympic-size swimming pools – broke away from the mountains surrounding Dickson Fjord and plunged into the water. The impact generated a mega-tsunami, reaching a height of roughly 650 feet. This surge of water traveled down the two-mile-long fjord, bounced off the headland at the end and then surged back, causing approximately $200,000 in damage to equipment at an unoccupied research station on Ella Island.

However, the initial wave wasn’t the end of the story. The water continued to oscillate back and forth within the fjord, creating a phenomenon known as a seiche – a standing wave. Computer models indicated the water level rising and falling as much as 30 feet in a consistent rhythm, exerting pressure on the seafloor like a massive piston. This sustained oscillation is what generated the unusual, long-lasting seismic signal.

Crustal Heartbeat at Dickson Fjord

Seismic stations typically record jagged, complex waveforms during earthquakes. In this case, the trace displayed smooth, evenly spaced peaks, occurring approximately every 92 seconds, and maintaining their strength for nearly two weeks. No previously observed seiche had produced such a persistent and widespread seismic signature. Initial modeling estimated the seiche’s amplitude at around 8½ feet, while another group calculated it to be between 23 and 30 feet. The discrepancy stemmed from differing assumptions about the precise shape of Dickson Fjord, but both simulations agreed on the landslide-driven wave as the origin.

“It was a big challenge to do an accurate computer simulation of such a long-lasting, sloshing tsunami,” explained Alice Gabriel of UC San Diego’s Scripps Institution of Oceanography. The unusual duration and global reach of the signal demanded sophisticated modeling techniques to understand the underlying physics.

Investigators Follow the Clues

The mystery attracted a collaborative effort involving over seventy researchers from forty-one institutions worldwide. “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. “All we knew was that it was somehow associated with the landslide. We only managed to solve this enigma through a huge interdisciplinary and international effort.”

Field teams identified fresh gouges high on the cliffs surrounding the fjord, providing evidence of the landslide’s scale and path. Simultaneously, supercomputers were used to recreate the avalanche’s trajectory and the fjord’s response. Robert Anthony of the U.S. Geological Survey emphasized the collaborative nature of the investigation: “It was exciting to be working on such a puzzling problem with an interdisciplinary and international team of scientists. It took a plethora of geophysical observations and numerical modeling from researchers across many countries to put the puzzle together and secure a complete picture of what had occurred.”

Warming Climate, Melting Glaciers

The stability of the slope that failed was compromised by the effects of a warming climate. Glacier ice, which once provided support, has been eroded by rising air and water temperatures. This loss of buttressing contributed to the landslide. As Greenland’s ice sheet continues to melt, similar instabilities are likely to occur in other fjord systems. “Climate change is shifting what is typical on Earth, and it can set unusual events into motion,” Gabriel noted. A similar event in Karrat Fjord in 2017 resulted in a deadly tsunami that destroyed homes and claimed lives, underscoring the potential hazards.

Dickson Fjord is located along a growing Arctic cruise route. While no vessels were present during the 2023 landslide, the incident highlights the increasing risks associated with Arctic travel. Authorities are now evaluating early-warning systems that integrate satellite data with real-time seismic monitoring to improve preparedness.

Satellites Sharpen the Picture

Traditional radar altimeters provide limited data, capturing only a narrow line beneath each spacecraft. However, the Surface Water and Ocean Topography (SWOT) mission, launched in December 2022, maps a 30-mile-wide swath with 8-foot resolution, offering a much more detailed view. “Climate change is driving the emergence of unprecedented extremes, particularly in remote regions like the Arctic, where our ability to monitor conditions using traditional physical sensors is limited,” explained Thomas Monahan of the University of Oxford.

Monahan continued, “SWOT represents a breakthrough in our ability to study oceanic processes in areas such as fjords – places that have long posed challenges for earlier satellite technologies.” This study demonstrates the transformative potential of next-generation Earth observation satellites in enhancing our understanding of dynamic environments. Professor Thomas Adcock, also from Oxford, remarked, “This study demonstrates how advanced satellite data can finally illuminate phenomena that have eluded us for years. We’re now gaining new insights into oceanic extremes like tsunamis, storm surges, and rogue waves. To fully harness the potential of these new datasets, we’ll need to push the boundaries of both machine learning and our understanding of ocean physics.”

Looking Ahead: Refining Disaster Forecasting

Researchers are now analyzing historical seismic data to identify similar slow-pulse signals, which could reveal previously undetected natural disasters. “This shows there is stuff out there that we still don’t understand and haven’t seen before,” said Carl Ebeling of Scripps. “The essence of science is trying to answer a question we don’t realize the answer to – that’s why this was so exciting to perform on.”

Ongoing research will focus on refining models that predict slope failure, fjord geometry, and water depth interactions. Improved forecasting capabilities could provide crucial warning time for ships and settlements in high-latitude waters. Even the most remote corners of the planet warrant careful monitoring, and this event underscores the importance of continued investment in Earth observation technologies and international scientific collaboration. The full study was published in the journals Science and Nature Communications.