The scientific community knows very little about the origins and composition of two massive rock formations located deep within the Earth’s mantle, on opposite sides of the planet.
At a depth of 2,896 kilometers below the Earth’s crust, halfway to the core of the planet, two gigantic rock masses are situated on opposite sides. One is located beneath Africa, while the other lies beneath the Pacific Ocean. These rock formations are scientifically referred to as Large Low Shear Velocity Provinces (LLSVPs), large continental-scale areas that differ from the surrounding mantle, according to IFL Science.
The two LLSVPs (in red) located in the Earth’s mantle. (Photo: IFL Science).
Imaging of the Earth’s internal structure shows the presence of these LLSVPs, but researchers know very little about them since scientists and probing equipment cannot reach the mantle. However, a particularly intriguing hypothesis about this mysterious phenomenon suggests that they are remnants from the Earth’s formation process 4.5 billion years ago. If this is true, they could provide immense insights into the Earth’s internal mechanisms as well as its complex history.
“The origin and composition of the LLSVPs remain unclear. We suspect they hold crucial clues about how the Earth formed and functions today,” stated Edward Garnero, a planetary interior expert at Arizona State University.
Garnero, along with other geologists at ASU, published research on the massive formations in the mantle in 2016, employing a combination of seismic, geochemical, and mineral physics data. While they did not explain the origins and composition of the LLSVPs, the paper revealed their role in the powerful geological forces observed on the surface, such as volcanic eruptions, tectonic plate movements, and earthquakes.
Many volcanoes are situated along the edges of tectonic plates, arising from great depths in the Earth when boundaries collide. Some are formed by mantle plumes, columns of hot rock rising from within the mantle. As they reach the Earth’s rigid outer crust, the magma cools and breaks through the surface, creating volcanoes.
Scientists speculate that the massive formation in the mantle beneath Africa and the Indian Ocean may penetrate the crust and create supervolcanoes capable of erupting for millions of years.
