A landslide in Greenland resulted in a tsunami that shook the Earth for nine days in September 2023, scientists found.

A mountain peak – which stood at 1.2km – collapsed into the Dickson Fjord in east Greenland on Sept 16, 2023, which triggered a 200m-tall wave. The peak contained about 25 million cubic m of rock, the volume of 25 Empire State Buildings, British media outlet BBC reported.

The wave caused water in the fjord to splash back and forth, causing vibrations in the Earth’s crust for nine days.

Though the wave fell to a height of 7m within a few minutes, and few centimetres in the days after the event, the movement of the water still sent seismic waves across the world.

An international team of scientists and the Danish Navy were involved in this study, which was published in the Science journal.

Tsunamis are typically caused by underground earthquakes, and their energy dissipates within hours in the open ocean. But this wave was trapped, according to the BBC.

“This landslide happened about 200km inland from the open ocean,” said Dr Stephen Hicks from University College London, one of the scientists involved. “And these fjord systems are really complex, so the wave couldn’t dissipate its energy.”

The seismic signal was picked up by sensors around the world, and researchers initially were not able to explain its cause, reported media outlets such as BBC, The Guardian and Sky News.

The researchers used seismic data to track the signal’s source to Dickson Fjord, after comparing its before and after photos.

“It definitely shows east Greenland is coming online when it comes to landslides,” said the study’s lead, Dr Kristian Svennevig from the Geological Survey of Denmark and Greenland.

“The waves destroyed an uninhabited Inuit suite at sea level that was at least 200 years old, indicating nothing like this had happened for at least two centuries.”

While the area is visited by some Arctic cruise ships, none were in the area when the landslide happened, BBC and The Guardian reported.

Rising temperatures in Greenland resulted in the landslide, as the glacier at the base of mountain had melted.

Dr Hicks said the glacier had been supporting the mountain, but it got “so thin” that it was no longer able to hold the mountain up.

He added: “It shows how climate change is now impacting these areas.”

Such events will become more common as temperatures around the world continue to rise, said Prof Anne Mangeney, a landslide modeller at the Institut de Physique du Globe de Paris, reported The Guardian.

This event, caused by climate change, led to a vibration felt everywhere across the world, she added.

“Those vibrations travelled from Greenland to Antartica in less than an hour,” said Prof Mangeney.

“So we’ve seen an impact from climate change impacting the entire world within just an hour.”