Africa's Hidden Force: A Massive Plume Pulling the Continent Apart

Topic: Earth Science

Scientists have discovered a massive plume of hot mantle material deep beneath Africa that is causing unusual motion in the continent. This finding helps explain why parts of East Africa are deforming differently than expected. The research team used computer models and GPS measurements to understand this phenomenon.

The African Superplume, an enormous zone of rising mantle material, begins deep beneath southwest Africa and extends northeastward across the continent. This vast upwelling of hot material is causing deformation in parts of East Africa that doesn't fit the usual pattern expected from a continent being stretched apart.

Geophysicist D. Sarah Stamps compared this phenomenon to Silly Putty, which can crack and break if hit with a hammer but stretches if pulled slowly. She used GPS stations that received signals from over 30 satellites orbiting Earth to track surface motion at the millimeter scale. Her observations showed that parts of East Africa were deforming in a direction parallel to the rift itself.

The team used 3D thermomechanical models to investigate what could be producing this unusual deformation. The simulations indicate that the rift parallel motion is linked to northward mantle flow associated with the African Superplume. This deep mantle flow can account for deformation that doesn't fit the simpler pattern expected from a continent being stretched apart.

The findings add new evidence to a long-running debate over what is driving the East African Rift System. Scientists have generally focused on two main possibilities: lithospheric buoyancy forces, mantle traction forces, or some combination of the two.

Why It Matters

This discovery can help us better understand how continents are formed and change over time. It also has implications for our understanding of earthquakes and volcanic activity in Africa.

Key Facts

• The African Superplume is an enormous zone of rising mantle material that begins deep beneath southwest Africa and extends northeastward across the continent.
• Geophysicist D. Sarah Stamps used GPS stations to track surface motion at the millimeter scale, showing that parts of East Africa were deforming in a direction parallel to the rift itself.
• The team's simulations indicate that the rift parallel motion is linked to northward mantle flow associated with the African Superplume.
• This discovery adds new evidence to a long-running debate over what is driving the East African Rift System.
• The research was published in the Journal of Geophysical Research and used computer models and GPS measurements to understand this phenomenon.

Key Terms

African Superplume

An enormous zone of rising mantle material deep beneath Africa.

Lithospheric buoyancy forces

Forces that act relatively close to the surface, influenced by differences in elevation and density within the lithosphere.

Mantle traction forces

Forces that originate deeper inside Earth, resulting from the movement of mantle material beneath the lithosphere.

Implications

This discovery can help us better understand how continents are formed and change over time. It also has implications for our understanding of earthquakes and volcanic activity in Africa.