In September 2023, a devastating and unprecedented natural event unfolded in the Arctic—an event that shook not only the icy landscape of Greenland but also reverberated through the entire planet. A massive glacier, melting due to the relentless advance of climate change, triggered a colossal landslide, which in turn set off a mega-tsunami with waves towering 650 feet high in a remote fjord of eastern Greenland. What followed was something no one had ever experienced or anticipated—a continuous seismic hum that lasted for nine days, perplexing scientists around the globe.
The phenomenon not only captured the attention of geologists and climate scientists but also became a chilling symbol of the dire consequences of a rapidly warming planet. The 2023 Greenland landslide and mega-tsunami are not merely local events—they represent a new frontier in the understanding of how climate change is destabilizing previously stable regions of the Earth, potentially unleashing catastrophic consequences.
In this blog, we will explore the causes, aftermath, and broader implications of the 2023 Greenland mega-tsunami, focusing on its connection to climate change, the scientific collaboration that unraveled the mystery, and the warnings it sends about the future of the Arctic and other vulnerable regions of the world.
The Initial Trigger: A Melting Glacier in Greenland
For years, the glaciers of Greenland have been thinning due to rising global temperatures. The Arctic is warming at a rate four times faster than the rest of the world, leading to increasingly unstable conditions in both the ice and the underlying land. This rapid warming has caused a steady retreat of the ice sheets and glaciers, exposing mountainsides and other geological formations that have remained stable for millennia.
The specific event that led to the 2023 disaster began with the gradual melting of a glacier located at the base of a massive mountain in eastern Greenland, towering nearly 4,000 feet above Dickson Fjord. As the glacier melted and thinned, it could no longer provide the support needed to stabilize the mountainside. On September 16, 2023, the weakened mountain collapsed, sending a staggering volume of rock and debris crashing into the fjord below.
In just moments, enough material to fill 10,000 Olympic-sized swimming pools was displaced, generating a wave 200 meters (about 650 feet) high, one of the tallest tsunamis in recent history. The wave raced through the fjord, which, due to its narrow and winding structure, acted as a trap, amplifying the wave’s power and causing it to slosh back and forth for more than a week.
The Cascading Hazard: Landslide, Mega-Tsunami, and Seiche
The term “cascading hazard” is used to describe events where one disaster sets off a chain reaction of other hazards, compounding the overall impact. In this case, the landslide caused by climate-induced glacier melting initiated a mega-tsunami, which then led to the formation of a seiche—a less-known phenomenon that involves the rhythmic sloshing of water in an enclosed or semi-enclosed space, such as a fjord, lake, or bay.
The seiche in Dickson Fjord was particularly powerful and long-lasting. Waves oscillated back and forth in the fjord every 90 seconds, driven by the immense energy of the landslide. This continued for nine days, generating seismic vibrations that traveled through the Earth’s crust. Seismologists around the world picked up these signals, which were unlike anything they had seen before. The event baffled experts initially, as it didn’t resemble the seismic patterns of earthquakes, which typically last for minutes, not days.
The seiche generated enough seismic energy to be detected by instruments across the globe. The ground vibration spread from Greenland to Antarctica in just an hour, marking the global reach of this Arctic disaster. Scientists dubbed the mysterious signal a “USO”—Unidentified Seismic Object—because of its unprecedented characteristics.
The Global Collaboration to Solve the Mystery
Understanding the cause of this nine-day seismic hum was no small feat. It required a nearly year-long collaborative effort between 68 scientists from 40 institutions in 15 countries. These experts analyzed data from seismic instruments, satellite images, field observations, and computer simulations to piece together the story of the Greenland mega-tsunami.
Dr. Stephen Hicks, a seismologist at University College London and one of the lead researchers on the study, recalled how he and his colleagues initially thought their instruments were malfunctioning. The seismic signal they observed was monotonous and lacked the high-pitched tremors typically associated with earthquakes. This led to widespread confusion among the scientific community.
The breakthrough came when seismologists traced the signal back to eastern Greenland. Around the same time, Danish researchers had received reports of a massive landslide in the remote Dickson Fjord. The two teams connected the dots, and with the help of satellite data and computer models of tsunami wave behavior, the full picture of the cascading hazard emerged.
The discovery of the nine-day seiche and its seismic signature represents a breakthrough in geophysical research. It was the first time scientists had directly observed the prolonged seismic effects of a natural event triggered by climate change. The unusual duration and scale of the seismic signal left experts grappling with the implications for future natural disasters in the Arctic and other regions undergoing rapid environmental change.
A Warning from the Arctic: The Impact of Climate Change
The 2023 Greenland mega-tsunami is a stark reminder of how climate change is pushing natural systems into “uncharted waters,” as one of the study’s co-authors, Dr. Kristian Svennevig from the Geological Survey of Denmark and Greenland, aptly put it. The Arctic, once considered a stable and frozen wilderness, is now transforming at an alarming rate, and this transformation is revealing new and dangerous phenomena.
For centuries, the glaciers and mountains of Greenland have been relatively stable. However, as global temperatures rise, the melting ice is weakening the structural integrity of mountains, increasing the risk of landslides. These landslides, in turn, can generate devastating tsunamis in the fjords that crisscross the region.
The landslide and tsunami in Dickson Fjord were the first of their kind ever recorded in eastern Greenland. Previously, similar events had only been documented in western Greenland, Alaska, and parts of Canada and Norway. This new event highlights how previously unaffected areas are now becoming vulnerable to the destabilizing effects of climate change.
The potential for future landslide-triggered tsunamis is a growing concern, not just for Greenland but for other regions with similar geography, such as Alaska, Norway, and parts of Canada. As the Arctic continues to warm, scientists expect to see more frequent and more severe events like the one in Dickson Fjord.
A Devastating but “Lucky” Outcome
While the 2023 Greenland mega-tsunami caused significant damage to the landscape and destroyed cultural heritage sites, including centuries-old Inuit settlements and an empty military base, no human lives were lost. This, as Svennevig noted, was a matter of pure luck.
The fjord where the landslide occurred is a popular route for cruise ships. Just two days before the tsunami struck, a cruise ship carrying 200 people became stranded in a nearby fjord, only to be freed shortly before the disaster. Had the ship still been in the area when the waves hit, the consequences could have been catastrophic.
The disaster also destroyed a historic research station on Ella Island, about 70 kilometers (45 miles) from the site of the landslide. The station, which had been used by scientists and Danish military personnel, was uninhabited at the time, sparing any casualties. However, the destruction of these heritage sites is a stark reminder of the cultural loss that accompanies climate-induced disasters.
The Future of the Arctic: Uncharted Waters
The 2023 Greenland landslide and mega-tsunami are just one example of the many ways in which the Arctic is changing. The region has become a bellwether for the planet’s response to global warming, with temperatures rising faster there than anywhere else on Earth. As the ice continues to melt and the permafrost thaws, scientists expect to see more frequent and more severe natural disasters, including landslides, tsunamis, and even earthquakes in regions previously considered geologically stable.
The implications of these changes go beyond the Arctic itself. As Dr. Hicks pointed out, this seismic event was felt around the world, demonstrating how interconnected the planet’s natural systems are. The vibrations from the Greenland seiche traveled from pole to pole, reminding us that the consequences of climate change are not confined to any one region.
In addition to the direct impacts of natural disasters, the melting of Arctic ice has global repercussions for sea level rise. Greenland’s ice sheet alone holds enough frozen water to raise global sea levels by more than 20 feet if it were to melt entirely. While such a scenario is still far off, the rapid melting of Arctic ice is already contributing to rising sea levels, which pose a threat to coastal communities around the world.
Conclusion: A Call to Action
The Greenland mega-tsunami of 2023 is a wake-up call for humanity. It is a vivid demonstration of how climate change is reshaping the planet in ways that are both unpredictable and dangerous. As the Arctic continues to warm, we can expect to see more events like this one—events that not only devastate local ecosystems and communities but also send shockwaves around the world.
The scientific collaboration that unraveled the mystery of the nine-day seismic hum is a testament to the power of global cooperation in the face of shared challenges. But while understanding these phenomena is crucial, it is not enough. The Greenland disaster is a reminder that the time for action is now. We must reduce greenhouse gas emissions, transition to sustainable energy sources, and take immediate steps to mitigate the effects of climate change.
If we fail to act, the Greenland mega-tsunami may be just the beginning of a new era of climate-induced disasters—an era in which the very ground beneath our feet becomes unstable, and the natural world behaves in ways we can scarcely imagine.
The Arctic is entering uncharted waters, and so are we. Let this disaster serve as a warning and a call to action for all of us to confront the climate crisis with the urgency it demands.
