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Climate scientists have warned of the increasing risk of megatsunamis with waves over 100 metres high as the melting glaciers in Greenland trigger massive landslides.

Researchers analyzed one such case of a huge tsunami that caused destruction in remote parts of East Greenland last year.

Recent tsunamis in Greenland have had devastating consequences, such as the 2017 Karratfjord landslide, which triggered a tsunami, flooded the village of Nuugaatsiaq and killed four people.

According to scientists, megatsunamis off the east coast of Greenland with waves over 100 meters high have also reached Europe.

Such a megatsunami occurred in Dickson Fjord in East Greenland in September 2023. Seismologists first mentioned it in social media posts and in letters reporting waves hitting a military facility on the island of Ella, more than 50 kilometers away.

Fortunately, no one was hurt, as the affected region was an unmanned military base at the time of the tsunami.

The new study, published in the journal The seismic recordings, evaluated earthquake signals and satellite images to reconstruct the sequence of events so that similar events can be better monitored in the future.

On September 16, 2023, a rock mass the size of a rugby stadium and about 50–100 m high broke off from a slope about 300–400 m high.

Scientists found that the landslide carried glacial ice with it and developed into a mixed rock-ice avalanche before it reached the water.

They found that the resulting megatsunami had a peak height of “over 200 m” and was up to 60 m high along a 10 km long section of the fjord.

While the original cause of the landslide remains a mystery, the investigation has clarified the direction and magnitude of the force it exerted.

It was found that the landslide and the resulting tsunami caused long-lasting vibrations in the fjord, with waves lapping back and forth in the narrow bay of the uninhabited fjord for more than a week.

“Earthquake monitoring stations up to 5,000 kilometers away recorded the tremors caused by the landslide,” the researchers wrote.

There was also a “very long-lasting” signal that seismometers recorded more than a week after the incident.

“What was unusual about it was its long duration,” said study co-author Angela Carrillo Ponce.

The researchers are convinced that the new findings can contribute to a better understanding of similar events and their possible connection to climate change.

“It is obvious that the retreat of glaciers that once filled entire valleys and the thawing of permafrost are leading to an increase in landslides,” the scientists wrote.

“Climate change is accelerating glacier melting and could therefore increase the risk of megatsunamis,” they added.