Unusual, previously unseen movements in the East Africa Rift Valley seem to be caused by superheated rock that is located deep within the Earth.
Unusual, previously unseen movements in the East Africa Rift Valley seem to be caused by superheated rock that is located deep within the Earth.
According to a recent study, the mysterious distortions connected to a massive tear in the planet’s surface that appears to be dividing Africa in two may be explained by a giant plume of super-heated rock rising up from close to the core of the planet.
Massive rifts in the Earth’s surface, known as continental rifts, are tearing up landmasses all over the world. The East Africa Rift, a network of valleys that stretches from the Red Sea to Mozambique and is approximately 2,175 miles (3,500 kilometres) long, is the largest active continental rift.
The deformation of the lithosphere, the planet’s outermost rigid layer, is what causes continental rifting. The shallowest portions of the lithosphere can change as it becomes thinner in a variety of ways, from pulling apart like dough to shattering.
D. Sarah Stamps, a geophysicist at Virginia Tech, compares Earth’s lithosphere’s responses to Silly Putty, comparing it to a hammer that can crack and break but stretch when pulled apart. Earth’s surface deforms at continental rifts at right angles to the rift’s length, causing land to stretch or break.
After examining the East African Rift for over 12 years, researchers found perpendicular deformation moving east and west, but also parallel to the rift, moving north. These unusual surface motions are unusual and have not been observed elsewhere.
According to a study, the irregularities on the surface of the Earth could be explained by a superplume of hot, buoyant rock rising from the mantle. This suggests plumes, particularly in continental rifts with thinned lithosphere, may actively contribute to deforming the Earth’s surface. As tectonic plates moved over Iceland, Hawaii, and the Galapagos, mantle plumes have been observed to form.
The African Superplume, which rises beneath southwest Africa and moves northeast across the continent, was the subject of the researchers’ attention. As it moves further north, it gets shallower.
The researchers used GPS technology to precisely measure surface motions at the East African Rift. Additionally, they examined the directions in which mantle rock slowly flowed over a large area using seismic instruments.
Finally, Tahiry Rajaonarison, the study’s lead author and a geophysicist at New Mexico Tech in Socorro, used 3D computer simulations to analyse the GPS and seismic data and determine the activity beneath the East African Rift.
The unusual deformations parallel to the rift may be caused by a northward mantle flow connected to the African Superplume, according to the 3D models.
According to Rajaonarison of Live Science, “imagine a stronger Silly Putty on top of a weaker Silly Putty, which represents the highly viscous lithosphere and the less viscous plume material, respectively.”
The stronger Silly Putty will eventually follow the weaker Silly Putty’s movement in the same direction if you move the weaker Silly Putty in the same direction.
Overall, Rajaonarison concluded that “the most significant implication of these findings is the improvement of our understanding of how continents break up.”