Unveiling Mystery: What Triggered Greenland's 2023 Landslide-Generated Tsunami?

Nuuk: In September 2023, a massive landslide in Greenland unleashed a chain of extraordinary events, including a towering 200-meter-high tsunami and a baffling nine-day seismic signal that left scientists around the world puzzled.

A recent study published in the journal Science reveals that the landslide resulted from the collapse of a glacier in Dickson Fjord, a remote area of eastern Greenland. This dramatic event triggered a mega-tsunami and produced a rare seismic signal that echoed across the globe, captivating the scientific community.

Glacier Collapse Led To Landslide 

"We were like, ‘Oh wow, this signal is still coming in. This is completely different to an earthquake,’" said Stephen Hicks, a seismologist at University College London, in an interview to US TV network. 

The signal, which persisted for nine days, was unprecedented and unlike anything previously observed.

"It kept appearing – every 90 seconds for nine days," Hicks added. 

This extended vibration, labeled as an unidentified seismic object (USO), puzzled experts because it didn't match the typical characteristics of an earthquake, which usually lasts just a few minutes.

Seismic Signal Mystery 

The mystery of the seismic signal was linked to a cascading hazard—a series of interconnected events fueled by climate change. The glacier, which had been melting for years due to the rapidly rising Arctic temperatures, ultimately thinned to a critical point. 

On September 16, 2023, a massive portion of the mountain above it collapsed, sending an enormous amount of debris—equivalent to filling 10,000 Olympic-sized swimming pools—crashing into the fjord below. This triggered a 200-meter-high tsunami. The wave became trapped in the narrow, winding Dickson Fjord, resulting in a back-and-forth motion known as a "seiche," which persisted for nine days. 

This rhythmic movement, similar to water sloshing in a bathtub, generated the seismic energy detected by global sensors. 

"If I had suggested a year ago that a seiche could last for nine days, people would have dismissed it as impossible," said Dr. Kristian Svennevig from the Geological Survey of Denmark and Greenland, the study's lead author.

 He likened the discovery to "suddenly finding a new color in a rainbow.