The scientific community knows almost nothing about the origin and structure of two continent-wide rocks located on opposite sides of the Earth’s inner mantle.
The two LLSVP blocks (red) are located in the Earth’s mantle. Image: IFL Science
At a depth of 2,896 km below the Earth’s crust, half the distance to the center of the planet, two giant rocks lie on opposite sides. One block lies beneath Africa while the other lies beneath the Pacific Ocean. These rock masses have the scientific name thermochemical masses or large low-slip mass provinces (LLSVP), continent-sized areas that are distinct from the surrounding Earth’s mantle, according to IFL Science.
Scans of the Earth’s internal structure show that the LLSVP mass is located there, but researchers know almost nothing about them, because it is impossible to send scientists or probes to the Earth’s mantle. However, a particularly interesting theory about this mysterious phenomenon is that they are traces from the formation of the Earth 4.5 billion years ago. If so, they could provide a wealth of information about the internal mechanisms of the Earth as well as its complex history.
“The origin and composition of the LLSVP blocks are unknown. We suspect they hold important clues about how the Earth formed and functions today,” said Edward Garnero, an expert on the internal structure planet at the University of Arizona, said.
Garnero, along with other geologists at ASU, published a study of the mantle giant in 2016, using a combination of seismic data, geochemistry and mineral physics. Although they do not explain the origin and composition of LLSVP, the paper reveals their role in the powerful geological forces we see on the ground such as volcanic eruptions, tectonic plate shifts and earthquakes .
Many volcanoes lie along the edges of the tectonic plate, rising from great depths in the earth as the boundaries collide. Some are formed by mantle plumes, columns of hot rock rising from within the mantle. As they reach the Earth’s hard outer shell, the magma cools and penetrates the surface, creating volcanoes.
Scientists speculate that the giant block in the mantle beneath Africa and the Indian Ocean will penetrate the crust and create a super volcano with the ability to erupt over millions of years.