Climate crisis in action: A tsunami that shook the world for days

A study recently published in the journal Science, involving more than 60 researchers around the world, has finally revealed the mystery of “a global signal that resonated for 9 days”.

The seismic signal in September 2023 was “picked up by sensors all over the world”, BBC reported, but it was unclear where it was originating from.

Cue in researchers who collaborated on pinpointing the exact trigger of the signal, and wrote in the journal that “a large rockslide occurred in Greenland on 16 September 2023 that generated a local tsunami” which was “energetic enough” for it to be picked up around the world, and kept on shaking the world for over a week.

Science editor Brent Grocholski wrote that the authors of the collaborative study “found that the signal was generated by standing waves in the Dickson fjord due to the rockslide”.

The authors, in the abstract they penned for Science, noted that “Climate change is increasingly predisposing polar regions to large landslides.”

This particular landslide was an event, the authors wrote, that “started with a glacial thinning–induced rock-ice avalanche of 25 × 106 cubic meters plunging into Dickson Fjord, triggering a 200-meter-high tsunami”.

The researchers link the tsunami that eventually “stabilised into a 7-metre-high long-duration seiche” that paralleled the seismic signal (The US National Ocean Service defines a seiche as “a standing wave oscillating in a body of water”.)

Phys.org interviewed Kristian Svennevig, the study’s lead author and a geologist at the Geological Survey of Denmark and Greenland (GEUS), who said "When we set out on this scientific adventure, everybody was puzzled and no one had the faintest idea what caused this signal."

"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," he added.

The researchers were, after combing through vast swathes of data, able to find the culprit.

Phys.org notes that “Climate change set the stage for the landslide by melting the glacier at the base of the mountain, destabilizing the more than 25 million cubic meters of rock and ice—enough to fill 10,000 Olympic-sized swimming pools—that ultimately crashed into the sea.”

"Climate change is shifting what is typical on Earth, and it can set unusual events into motion," said seismologist Alice Gabriel of UC San Diego's Scripps Institution of Oceanography, one of the co-authors of the study.