Giant tsunami that shocked the world for 9 days revealed in new satellite images

Scientists finally solved the mystery behind two strange events that shocked the entire planet for nine consecutive days. Their discovery ends the book with years of efforts to trace earthquake signals back to their source.

In September 2023, a global seismometer discovered something strange. The earth trembled slightly every 90 seconds, and the shaking lasted for nine days. A month later, it happened again. Scientists are confused because natural construction processes cannot explain the exception.

After about a year of scientific investigation, two studies were published in 2024 independent Assumptions The shock was caused by two huge landslides, introducing two “Mega-Tsunamis” in Dickson Fjord in East Greenland. These huge standing waves (or seiches) walk back and forth within the fjord and trigger small movements within the earth's crust.

This is an interesting possibility, and both studies provide compelling evidence to support their claims. But, “there are some great uncertainties that make it difficult to fully confirm that this is actually the root cause,” Thomas Monahan, a science researcher at Oxford University, told Gizmodo.

So Monahan and his colleagues set out to confirm whether this assumption is correct. In a study published today in the Journal Natural CommunicationsThey reveal the first direct satellite observations of seiches and associate them with earthquake anomalies.

The researchers used data captured by NASA's surface water sea-shaped (SWOT) satellites. emission December 2022 to map 90% of the water height on the surface of the earth. This type of data collection, called a satellite altimeter, passes radar pulses from the satellite to the Earth's surface, and then measures the time it takes for the signal to bounce from the surface and return to the satellite.

Oxford University's Note statement. Monaghan said that due to the complexity of the terrain, they often have difficulty collecting data in the fjord area. But the SWOT is equipped with a cutting-edge altimeter instrument that triangulates the return signal using two antennas. This allows satellites to make very high-resolution measurements of surface water levels.

“What we were able to get is essentially an incredible high-resolution snapshot of what the sea surface does in these complex areas,” Monaghan said. These snapshots provide a more accurate description of how the sea surface height of the fjords changes during the 2023 earthquake event, allowing his team to calculate the slope of the large waves formed.

“We were actually able to unearth the fact that the fjord is exactly what we expected to do, and there was a major abnormality in the fjord,” Monaghan said.

However, it is not enough to prove that these strange SEI quakes were formed simultaneously in strange seismic signals, which is linked to both events. Researchers need direct evidence that these huge waves can produce global tremors.

To do this, they linked SWOT snapshots to small actions in the Earth's crust found at earthquake stations thousands of miles from the fjord. Combining this continuous seismic data with intermittent satellite observations allows them to reconstruct the wave's characteristics even during periods not observed by SWOT. The researchers also specified the possibility that seismicity originated from weather or tidal conditions and finally determined that these seiches were the source of tremor.

Monaghan said these waves formed when the warming glacier collapsed. “This created a very large landslide, and when they hit the fjord, it produced a huge giant tsunami at an altitude of 200 meters or 600 feet,” he explained.

“This is the first time that this is a giant tsunami of this nature has occurred in eastern Greenland.” He said it was “concerning” to see the phenomenon spread to other parts of the ice sheet, as it suggests that climate change is accelerating in the region.

“I think what this study really emphasizes is – well, it sounds stupid, but climate change is a global phenomenon,” Monaghan said.

“Some of the biggest and fastest changes are happening in the Arctic and remote areas, and we may not see it every day. But it is important to understand and quantify these changes because they ultimately affect where we live.” Indeed, the waves that shock the world remind people of the huge impact of global temperature rise.