A tsunami stemming from a landslide in a Greenland fjord, caused by melting ice, was behind a surprising seismic event last year that shook the earth for nine days, a researcher told AFP on Friday.

According to a report recently published in the scientific journal Science, tremors that were registered in September 2023 originated from the massive wave rocking back and forth in the Dickson fjord in Greenland’s remote east.

“The completely unique thing about this event is how long the seismic signal lasted and how constant the frequency was,” one of the authors of the report, Kristian Svennevig, from the Geological Survey of Denmark and Greenland, told AFP.

“Other landslides and tsunamis have produced seismic signals but only for a couple of hours and very locally. This one was observed globally all the way to the Antarctic,” he said.