Greenland’s Mega-Tsunami: The Nine-Day Earthquake Phenomenon
In an awe-inspiring event in 2023, a mountaintop collapse in Greenland triggered a colossal mega-tsunami towering roughly 200 meters (650 feet). This giant wave wreaked havoc within the narrow confines of the Dickson Fjord, creating seismic waves that reverberated through the Earth’s crust for an astonishing nine days.
Unveiling the mystery
When scientists first detected an unusual seismic signal in 2023, it defied their expectations. Unlike the typical frequency-rich rumble of earthquakes, this event emitted a monotonous hum with a single vibration frequency.
Determined to unravel the mystery, an international team of scientists traced the seismic signal back to the tsunami waves in Greenland. Their groundbreaking study has been published in the journal Science.
“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,” stated Kristian Svennevig, a geologist at the Geological Survey of Denmark and Greenland (GEUS) and the study’s lead author.
The scale of destruction
The scale of the event was mind-boggling. Rock and ice equivalent to filling 10,000 Olympic-sized swimming pools cascaded into the fjord, triggering the 200-meter-high mega-tsunami and a phenomenon known as a seiche, where waves continue to slosh back and forth within a confined area. This seiche rocked the fjord approximately 10,000 times over nine days, marking it as the tallest wave recorded on Earth since 1980.
The wave dwarfed previous tsunamis, including those caused by undersea earthquakes in Indonesia in 2004 and Japan in 2011, as noted by the study’s authors.
Stephen Hicks, Research Fellow in Computational Seismology at UCL, and Kristian Svennevig, Senior Researcher at the Geological Survey of Denmark and Greenland, revealed that 66 scientists from 40 institutions across 15 countries collaborated to pinpoint the source of the mysterious signal.
The role of climate change
The study’s authors pointed to climate change as the driving factor behind the catastrophic collapse. Global heating had “thinned the glacier by several tens of meters, meaning that the mountain towering above it could no longer be held up.”
“The landslide traveled down a very steep glacier in a narrow gully before plunging into a narrow, confined fjord,” they wrote.
Future implications
Scientists warn that this event is unlikely to be an isolated occurrence. “As permafrost on steep slopes continues to warm and glaciers continue to thin, we can expect these events to happen more often and on an even bigger scale across the world’s polar and mountainous regions,” they cautioned.
This dramatic event serves as a stark reminder of the far-reaching impacts of climate change and the urgent need for global action to mitigate its effects.