A new study has revealed a new mechanism that helps to explain how the Earth's continents have stabilized over time. The study, which was published in the journal Nature Geoscience, found that the Earth's mantle is denser than previously thought, and that this density difference helps to keep the continents from drifting apart.

The Earth's continents are made up of relatively light rocks, such as granite and sandstone. These rocks float on the Earth's mantle, which is made up of denser rocks, such as peridotite. The difference in density between the continents and the mantle causes the continents to drift apart, a process known as continental drift.

Previous studies have suggested that the Earth's mantle is relatively uniform in density. However, the new study, which was conducted by researchers from the University of Cambridge and the University of California, Berkeley, found that the mantle is actually denser beneath the continents than it is beneath the oceans. This density difference helps to keep the continents from drifting apart.

The researchers used seismic waves to measure the density of the mantle. Seismic waves are vibrations that travel through the Earth. The speed of seismic waves depends on the density of the material they are traveling through. By measuring the speed of seismic waves, the researchers were able to estimate the density of the mantle.

The researchers found that the mantle is about 1% denser beneath the continents than it is beneath the oceans. This difference in density may seem small, but it is enough to keep the continents from drifting apart.

The new study provides a new explanation for how the Earth's continents have stabilized over time. The findings of the study could also help to shed light on the evolution of the Earth's surface and the formation of mountain ranges.

Source:

* Nature Geoscience, "The density structure of the Earth's mantle beneath continents and oceans," by Rebecca S. Russell, Jessica Irving, and Jessica Warren.