Seismic waves resolve continental debate

Analyses of seismic waves that travel deep within Earth may resolve a decades-old debate about the thickness of the planet’s continents.

Some studies have suggested that the major landmasses in Earth’s rigid outer shell–including the planet’s crust and the upper layers of its mantle–are between 200 and 250 kilometers thick. To arrive at those estimates, researchers considered phenomena such as heat flow from within the planet.