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, where volcanism and earthquakes are often concentrated.

The continents we now recognize were once united as single, great “supercontinents.” One such example was Gondwana, which existed hundreds of millions of years ago and started to break up during the age of the dinosaurs. We believe that when these supercontinents break apart, it triggers a kind of stirring process under the continents, which we now call a “mantle wave.” This motion deep in the Earth ripples slowly across the partially molten underbelly of the landmass, disturbing its deep roots.