Gargantuan Waves in Earth’s Mantle May Cause Continental Uplift

New research suggests that enormous waves within Earth’s mantle, triggered by the breakup of continents, could be responsible for the formation of dramatic landforms such as high plateaus and steep cliffs. As continents split apart, massive cliff walls often rise near the boundaries where the crust is separating. This rifting generates waves in the mantle that propagate inward over tens of millions of years, driving the uplift of plateaus.

Published on August 7 in Nature, this study sheds light on a geological process linking these features through deep mantle waves. Thomas Gernon, a geoscientist at the University of Southampton and lead author of the study, highlights that these formations were previously thought to be the result of different processes. However, this new research suggests they share a common origin.

Gernon and his team focused on three notable escarpments formed during the breakup of Gondwana, Earth’s last supercontinent. These include the escarpment along India’s Western Ghats, one encircling Brazil’s Highland plateau, and the Great Escarpment in South Africa. Their analysis showed that these escarpments align with continental rifts, indicating that they were shaped by the same process. Computer simulations confirmed that rifting disturbances in the mantle create deep waves that move inward, impacting the rise of plateaus.

The study also examined mineral data, revealing that the uplift and erosion of these plateaus occurred in sync with the mantle waves. These waves advance very slowly—at about 9 to 12 miles every million years—peeling away the strong roots anchoring continents. This gradual process makes the continents more buoyant, leading to their elevation.

The research suggests that similar mantle wave processes might explain other escarpment and plateau regions globally. However, older formations might have been significantly altered by erosion, making them harder to study. This work underscores how ancient geological processes can have lasting impacts on Earth’s landscape.