American scientists have found evidence that the remnants of another planet within the Earth have driven the process of plate tectonics.
A recent study published in Geophysical Research Letters reveals that the hidden planet within the Earth is Theia, with a portion that has not completely melted forming the “color spots” identified by geophysical data in the area above the outer core, just beneath the mantle.
Theia is a hypothetical planet the size of Mars that collided with the early Earth approximately 4.5 billion years ago.
Graphic depicting the collision between Earth and Theia in the past, with the left half showing the collision and the right half depicting the present-day Earth with remnants of Theia near the core and the Moon formed from the collision – (Graphic: CALTECH).
The collision caused both young planets to shatter, with most of Theia’s material mixing into the Earth, while a small portion was ejected into orbit, merging with debris from Earth to gradually form the Moon.
The “color spots” from Theia—known as LLVPs—are areas where the speed of seismic waves becomes unusually low when passing through.
In this new study, a research team from the California Institute of Technology (Caltech) utilized computer models to demonstrate the type of impact that LLVPs could have on the Earth’s crust over millions of years.
According to a summary of the research published in the scientific journal PHYS, the models indicate that about 200 million years after Theia collided with Earth, the pressure from the LLVPs led to the formation of hot flows extending from near the core to the surface.
This caused certain surface areas to sink, resulting in subduction phenomena. The eventual subduction led to fractures on the surface, which today serve as boundaries for tectonic plates.
Tectonic plates can be understood as the Earth’s crust. It is estimated that there are around 20 major and minor plates that continuously move. Some plates continue to dive beneath others due to subduction, while others slide over the top.
Tectonic plates “carry” continents and oceans on their backs, thus the process of plate tectonics has repeatedly formed supercontinents located amidst vast superoceans, only to later separate as we see today.
Plate tectonics is also the main cause of many geological phenomena such as earthquakes, volcanoes, mountain building, and the formation of new ocean floors…
Researchers believe their model may explain why some of the oldest minerals on Earth show evidence of subduction.
