Global earthquakes have puzzled scientists for years, but two new studies have finally solved the mystery behind nine days of strange seismic signals detected by seismometers worldwide. Researchers at the University of Oxford used satellite data to confirm that massive landslides in East Greenland triggered “mega-tsunamis” in Dickson Fjord, causing the earthquakes.
The 2023 and 2024 studies suggested that two huge landslides created standing waves, known as seiches, inside the fjord. However, scientists had uncertainties about this theory. To confirm or rule out their hypothesis, a team led by Thomas Monahan analyzed data from NASA’s Surface Water Ocean Topography (SWOT) satellite.
The SWOT satellite provided high-resolution measurements of surface water levels in the fjord, allowing researchers to calculate the slopes of massive waves that formed during the earthquakes. They linked these wave characteristics to small movements in the Earth’s crust detected at seismic stations thousands of miles away from the fjord.
Using this data, Monahan and his team found that the seiches were indeed the source of global tremors. The researchers discovered that warming glaciers collapsing on themselves created massive landslides that triggered 200-meter or 600-foot-tall mega-tsunamis in the fjord. This phenomenon has only been documented on Greenland’s west coast, but its occurrence in Eastern Greenland is a cause for concern.
Monahan emphasized that climate change is accelerating globally and that remote regions are experiencing significant changes. The study highlights the need to understand and quantify these changes as they will eventually impact us worldwide.
Source: https://gizmodo.com/mega-tsunamis-that-shook-the-world-for-9-days-revealed-in-new-satellite-images-2000610544