In September 2023, a massive landslide in Greenland led to a series of extraordinary events, including a 200-meter-high tsunami and a mysterious nine-day seismic signal that intrigued scientists worldwide. A recent study published in Science reveals that the landslide resulted from the collapse of a glacier in Dickson Fjord, a remote area in eastern Greenland. This collapse triggered a mega-tsunami and produced an unusual seismic signal that echoed around the globe.

 

The seismic event, initially baffling, sparked widespread intrigue. “We were amazed that this signal kept coming in. It was completely different from an earthquake,” said Stephen Hicks, a seismologist at University College London, in an interview with CNN.

The signal, which persisted for nine days, was unprecedented. “It kept reappearing every 90 seconds for nine days,” Hicks noted. This extended vibration, termed an unidentified seismic object (USO), puzzled experts as it did not match the typical short duration of an earthquake.

Seismologists were able to trace the unusual vibrations to eastern Greenland but struggled to identify the exact cause. Researchers from Denmark eventually identified a landslide-induced tsunami in Dickson Fjord as the source. This discovery led to a nearly year-long collaboration among 68 scientists from 15 countries to resolve the mystery behind the nine-day seismic anomaly.

 

5 Shocking Facts About Greenland’s Landslide The mystery behind the seismic signal was traced to a cascading hazard—an interconnected series of events driven by climate change. The glacier, which had been thinning for years due to accelerating Arctic temperatures, reached a critical point on September 16, 2023, leading to the collapse of a large section of the mountain above it.

This collapse unleashed a massive volume of debris, equivalent to 10,000 Olympic-sized swimming pools, into the fjord below, generating a 200-meter-high tsunami. The wave became trapped in the narrow and winding Dickson Fjord, causing a “seiche” effect, where the wave bounced back and forth for nine days.

This rhythmic motion, similar to water sloshing in a bathtub, created the seismic energy detected by global sensors. Dr. Kristian Svennevig from the Geological Survey of Denmark and Greenland, lead author of the study, remarked that if he had predicted a seiche lasting nine days a year ago, people would have thought it impossible, likening the discovery to “suddenly finding a new color in a rainbow.”

 

The seismic signal from the event was so intense that it was detected worldwide, with sensors in Antarctica picking up the vibrations within hours. Although no lives were lost, the tsunami destroyed centuries-old cultural heritage sites and damaged an abandoned military base in the area. Scientists highlighted that if a cruise ship had been in the region, a commonly traveled route, “the consequences would have been catastrophic,” according to the study’s authors.

 

5 Shocking Facts About Greenland’s Landslide Experts warn that this event highlights the profound impact of climate change on the Arctic landscape. In recent decades, the Arctic has warmed four times faster than the global average, causing glaciers to melt at unprecedented rates. As these glaciers thin, the stability of the mountain slopes they support diminishes, increasing the risk of future landslide-triggered tsunamis.

“This is the first massive landslide and tsunami we’ve recorded in east Greenland,” noted Svennevig. “It clearly indicates that east Greenland is becoming a hotspot for landslides.” He also pointed out that with rising temperatures, similar events are likely to become more frequent, not only in Greenland but also in other regions with comparable geographical features, such as Alaska, parts of Canada, and Norway.

The 2017 tsunami in northwest Greenland, which resulted in four deaths and destroyed several homes, underscores the potential dangers of such events. Scientists caution that these disasters will likely become more common as glaciers continue to melt.

“We are thawing ground that has been frozen for thousands of years,” said Paula Snook, a landslide geologist at the Western Norway University of Applied Sciences. She described recent rock avalanches in both the Arctic and Alpine regions as an “alarming signal” of climate change’s destabilizing effects.

 

5 Shocking Facts About Greenland’s Landslide Although much remains to be investigated, researchers are now concentrating on assessing the broader implications of climate-induced geological hazards. “It’s reasonable to expect more frequent rock collapses on permafrost slopes as Arctic temperatures rise,” said Lena Rubensdotter, a geologist at the Geological Survey of Norway.

The findings from the Greenland event highlight the critical need for expanded research and surveillance of climate change’s influence on geomorphic processes. “This signals that climate change is driving these systems into uncharted territory,” noted Svennevig, emphasizing the unpredictable nature of cascading hazards and the potential risks for geologically vulnerable areas worldwide.

 

The extraordinary landslide and seismic event in Greenland underscore the severe impact of human-induced climate change on the rapidly shifting Arctic conditions. This study’s findings emphasize the growing likelihood of more frequent and severe natural disasters in the region, calling for global awareness of the escalating risks associated with climate change.