We discovered a new way mountains are formed – from ‘mantle waves’ inside the Earth

In 2005, I was navigating winding roads through the Drakensberg Mountains, in Lesotho, Southern Africa. Towering cliff-like features known as escarpments interrupt the landscape, rising up by a kilometer or more. Taken aback by the dramatic scenery, I was struck by a question: how on Earth did it form?

The outer shell of our planet is fractured into seven or eight major sections, or tectonic plates, on which the continents sit. We expect to see the continents rise up at the active boundaries of these plates...