Seismic waves suggest the presence of newly identified “Ultra-Low Velocity Zones”. This could be a sign of the “ghost planet” Theia.
Previously, scientists discovered two unusual structures resembling supercontinents emerging from the core-mantle boundary and extending high within the Earth’s mantle. They believe these may be remnants of a planet that was “devoured” by the early Earth.
These structures are known as “Ultra-Low Velocity Zones (ULVZ)”, identified due to the abnormal slowing of seismic waves as they pass through them.
Large remnants of a hypothetical planet may still be intact beneath your feet, no matter where you stand in the world – (AI Illustration: Anh Thư).
Now, a new study indicates that there are not just two ULVZs; they appear to be widespread throughout the mantle.
According to Live Science, the new research utilized data from 58 deep earthquakes with magnitudes greater than 5.8 (on the Moment Magnitude scale) that occurred from 2008 to 2022 near New Guinea.
The waves from these earthquakes traveled through the planet’s core and up to North America, where they were recorded by EarthScope, a project deploying mobile seismic monitoring equipment across the United States.
Some of these planetary seismic waves would pass through the ULVZ in the western Pacific, one of the two known ULVZs within the Earth.
However, results published in AGU Advances reported the detection of seismic wave variations even at monitoring stations that did not record waves passing through the western Pacific ULVZ.
The path of the studied waves certainly did not pass through the ULVZ beneath Africa.
The only explanation is that additional ULVZs exist, where seismic waves could lose up to 50% of their speed when traversing.
The researchers believe that if the examination is expanded to include other monitoring stations on Earth, “strange signals” will appear in seismic waves everywhere.
According to geophysicist Michael Thorne from the University of Utah, the lead researcher, these extreme ULVZs remain shrouded in mystery, and no one has definitively determined what they are.
Nonetheless, many scientists lean towards the hypothesis that the ULVZs are remnants of the “ghost planet” Theia.
This hypothetical planet, about the size of Mars, collided with the early Earth approximately 4.5 billion years ago, a collision that blasted debris into orbit and created the Moon.
The materials from the two planets mixed but did not fully homogenize, and some large fragments of Theia may be scattered somewhere within the Earth’s structure.
Because they originate from another planetary body, composed of somewhat different materials than those of Earth, seismic waves change as they pass through these planetary remnants, forming ULVZs.
Of course, this is still just a hypothesis. However, it seems to be gradually clarified through new findings related to ULVZs and research on the Moon.
