Scientists Finally Know the Secret Behind the Mysterious Nine-Day Vibrations That Were Felt Around the World in 2023
In 2023, the whole world was shaken for nine consecutive days. At that time, nobody could figure out the cause of this shaking. Recently, a team of researchers has supposedly resolved this mystery with the help of satellite readings, stated Live Science. Findings regarding these observations have been published in Nature Communications.
As per the study, the cause was two mega tsunamis that were moving within an East Greenland fjord. In September 2023, the giant waves arrived in the Dickson Fjord and rocked back and forth for around nine days. This movement essentially caused the seismic waves that were vibrating the planet's crust.
The vibration reportedly happened every 90 seconds across nine days in September, and then recurred a month later, according to Eureka Alert. The study claims that the two mega tsunamis, which caused the seismic waves, were triggered by two major landslides. These landslides supposedly happened because of an unnamed glacier's warming. This phenomenon had long been suspected to be the cause of the mysterious seismic activity, but prior to the study, researchers did not have solid evidence to back their assertion.
In this study, the team of experts applied novel analysis techniques to figure out Dickson Fjord's satellite altimetry data during the seismic waves. This data records the height of the Earth’s surface (including the ocean) at that point in time. This measurement is determined by calculating how long it takes for a radar signal to travel from a satellite to the surface and then back again.
The data was gathered with the help of readings undertaken by the Surface Water Ocean Topography (SWOT) satellite, which was launched back in 2022. The Ka-band Radar Interferometer (KaRIn) instrument inside the SWOT used two antennas mounted on each side of the satellite to take the observations. These antennas triangulate the return signals sent by the radar pulse, allowing them to get surface measurements with impeccable accuracy.
These measurements were applied by experts to create Dickson Fjord's elevation maps at different times after the tsunamis. The maps exhibited several cross-channel slopes with a two-metre height difference. The slopes were in the opposite direction, which implies that water was moving back and forth in the channels. This indicated that a massive movement did take place in the fjord during that time, capable of sending massive signals all across the Earth.
To further confirm the theory, the readings were aligned with the small movements noticed in the Earth's crust thousands of kilometres away. This allowed the experts to reconstruct how waves possibly travelled from the fjord to other places. The results indicated that the tsunamis indeed sent the reverberations.
The weather and tidal conditions at that time also affirmed the speculation. “Climate change is giving rise to new, unseen extremes. These extremes are changing the fastest in remote areas, such as the Arctic, where our ability to measure them using physical sensors is limited. This study shows how we can leverage the next generation of satellite earth observation technologies to study these processes,” Lead author Thomas Monahan (DPhil student, Department of Engineering Science, University of Oxford) said. “SWOT is a game changer for studying oceanic processes in regions such as fjords, which previous satellites struggled to see into.”
One of the tsunamis was estimated to be 650ft (200 metres) in height by experts, according to the Daily Mail. The study claims that the tsunamis exerted a force of 500 Giga Newtons, equivalent to what is produced by 14 Saturn V rocket ships launching at once. This force was enough to shake the world for days on end.