How Earth’s mantle shapes its surface

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The rocky landscape of our planet is a masterpiece crafted by the intricate dance of tectonic plates.

We know how these plates colliding or moving apart shape mountains and ocean depths.

But did you know that beneath these plates lies another player in this geological symphony?

It’s the mantle, Earth’s hidden layer, influencing the surface in surprising ways.

In a recent study published in the Journal of Geophysical Research: Solid Earth, Stephenson and their team delved into this hidden world.

They gathered data from across the globe, compiling the most extensive database yet on crust thickness and seismic velocity.

With this information, they untangled how the mantle’s temperature and chemistry sculpt Earth’s surface, creating what scientists call residual topography.

Imagine gentle swells and deep basins stretching across continents, not just at plate edges but within the heart of plates.

These features, rising or falling by up to 2 kilometers and spanning hundreds to thousands of kilometers, are the mantle’s fingerprints on our landscapes.

Some of the highest swells, reaching about 2 kilometers tall, are found in regions like Afar–Yemen–Red Sea, western North America, and Iceland.

These spots indicate where the mantle is exceptionally hot.

On the other hand, the deepest basins, plunging deeper than 1.5 kilometers, lie near the Black, Caspian, and Aral seas, as well as in the East European Plain, where the mantle is cooler.

These mantle-driven features play a crucial role in Earth’s geological processes. They guide erosion and sedimentary deposition, influencing how our landscapes evolve over millions of years.

Moreover, they offer insights into phenomena like magmatism far from plate boundaries and the mysterious flow of the mantle through time.

Understanding the mantle’s influence on our surface helps us grasp the dynamic forces shaping our world. It’s a reminder that even beneath our feet, unseen processes are at work, shaping the very ground we walk on.

Source: American Geophysical Union.