While Alfred Wegener is famously known for the theory of continental drift, he struggled to explain the driving force behind it. Holmes, in the 1930s, proposed that convection currents within the Earth's mantle were the mechanism driving the movement of continents.

He suggested that heat from the Earth's core created these currents, which would then drag the lithospheric plates (including the continents) along with them. This concept became a crucial element in the development of the modern theory of plate tectonics.