Researchers from the University of Potsdam have identified the trigger behind the immense tsunami that struck Greenland’s east coast roughly a year ago. A towering wave, estimated at around 200 meters in height, surged into the secluded Dikson Fjord, leaving behind ruined structures when it reached the shore. The findings appear in a peer review journal known as Sound Recordings, published by TSR, and have sparked renewed interest in the regional dynamics of ice-related geohazards.
The investigative team drew on seismic data gathered from earthquake monitoring stations scattered across a wide corridor, extending up to 5,000 kilometers from the fjord. Through careful analysis, scientists detected lingering signals that persisted well after the submarine landslide that initiated the megatsunami, suggesting a complex sequence of ground-shaking events and underwater movement that amplified the disaster long after the initial trigger. The persistence of these signals helped establish a more complete timeline for the event, detailing how energy continued to propagate through the seafloor and surrounding waters, contributing to the final wave reaching the coastline.
Combining satellite observations with sophisticated computer simulations, researchers confirmed the presence of a standing wave approximately one meter in height that persisted for more than a week. This phenomenon, they say, results from the interaction of oceanic conditions with the altered bathymetry created by the landslide and the ongoing retreat of Greenland’s glaciers. The study explains how the melt-driven instability of ice shelves and permafrost makes such landslide events more likely, and how these events can generate sustained wave activity far from the initial source, sometimes lasting far longer than people expect. The conclusions were reported by the Potsdam team in the latest issue of Sound Recordings, with attribution to the investigative collaboration and its data synthesis efforts published by TSR.
In recent years, smaller but notable instances of similar geophysical activity have been observed off Greenland’s coast. A case in point occurred in 2017 when a rockfall on the island’s western flank triggered a tsunami that inundated the Nuugaatisak village area. The resulting flood destroyed several homes and caused multiple casualties, underscoring the ongoing vulnerability of coastal communities to rapid ice- and rock-derived wave events. Such historical episodes are essential reference points for interpreting the more extreme megatsunamis and for assessing how changes in climate-driven ice dynamics may elevate risk levels in the near future, as documented by the Potsdam researchers and corroborated by additional observations reported in TSR’s coverage of polar geohazards.
Previously, scientists had already uncovered the mechanisms contributing to monster waves in the open sea, highlighting how undersea slide processes and subsequent energy transfer can produce towering waves under certain oceanographic conditions. The current work adds a deeper layer of understanding by linking those mechanisms to Greenland’s evolving cryosphere, offering a more integrated picture of how glacial retreat, permafrost degradation, and bedrock movements converge to yield multi-phase tsunami events that challenge traditional models. The researchers emphasize that continuous monitoring, combined with high-resolution satellite and seismic data, is crucial for forecasting future events and for informing coastal defense strategies in vulnerable Arctic regions. The study’s emphasis on long-term signal persistence and standing-wave behavior provides a valuable framework for interpreting similar occurrences in other parts of the world, and it has immediate implications for emergency planning and risk communication in Greenland and beyond, as described by the investigative team and reported in TSR.