Researchers Discover the Source of Puzzling Seismic Activities
In September 2023, a global seismic event occurred, causing the Earth to shake non-stop for nine days. Seismic stations worldwide recorded an unusual signal, unlike regular earthquakes. Scientists from various institutes, including the Karlsruhe Institute of Technology (KIT), collaborated to uncover the cause of this continuous trembling.
Thomas Forbriger, a KIT scientist, reported that the signal was an oscillation with a dominant frequency, similar to a monotonous hum gradually fading away. Over 60 researchers from 15 different countries joined forces to investigate.
The intriguing mystery of the continuous shaking has now been solved: It was due to a massive landslide on September 16, 2023, in Greenland's Dickson Fjord. An entire mountain peak, initially 1200 meters high, collapsed, causing a cascade of over 25 million cubic meters of material. An astronaut from the Geological Survey of Denmark and Greenland confirmed this, stating that the volume was enough to fill 10,000 Olympic swimming pools.
Gargantuan 200-Meter Tsunami
The landslide displaced a significant amount of water in the fjord, generating a 200-meter-high water fountain and a wave reaching up to 110 meters, spanning over 10 kilometers of the fjord. However, researchers calculated that the tsunami diminished to just seven meters within minutes. Surprisingly, the water continued to slosh back and forth for days, mimicking a bathtub, with a period of about 90 seconds in the narrow fjord, matching the observed seismic wave oscillation period. Their findings were published in the journal "Science".
Rudolf Widmer-Schnidrig of the University of Stuttgart, who also participated in the study, suggested that the Dickson Fjord has a unique capacity for such oscillations. He also mentioned that there are few reports of such frequent, prolonged water oscillations in the scientific literature.
Research Base Ravaged by Tsunami
The seismic waves from the oscillating water traveled around the Earth, making it observable even in Antarctica, almost 20,000 kilometers away. According to the study, this gigantic tsunami was one of the highest recorded in recent history. It reached a height of four meters outside the fjord, causing damage to a research base on the Ella island, 70 kilometers away.
Climate change is believed to be the reason behind the massive landslide that ultimately led to the mega-tsunami. Satellite images revealed that the glacier at the mountain's base had significantly receded in recent decades. This was the first-ever observed landslide and tsunami event in northeast Greenland. A study published by researchers from the German Research Centre for Geosciences (GFZ) in August had already hinted at the formation of the tsunami.
The location of the landslide that triggered the mega-tsunami was identified as Greenland's Dickson Fjord. Due to climate change, satellite images indicated that the glacier at the mountain's base had receded significantly in recent decades.
