THE EARTH AIN'T ROUND

Gravity is constantly shaping the Earth’s surface

By Joshua Hawkins
October 17th, 2022

A new study has revealed that gravity’s effect on Earth is constantly shaping the surface of our planet. When our planet formed, it did so by pulling dust and rock toward its gravitational field. As the sphere swelled, the gravitational pull continued to gather more material. Now, gravity’s effect on the Earth continues to mold our planet from deep within.

This idea was posed in a recent study where the researchers looked at the subtle effects that gravity has been having on deep-lying structures within our planet. The study highlights the effects gravity has on Earth and how it can even cause the rise and fall of the crust above it.

To truly understand this conundrum, we have to look at how gravity works as a whole. For the longest time, scientists worked based on the equation that g = 9.8 ms–2. However, new studies have shown that gravity is not constant for the entire planet. Instead, this force can vary depending on where you are. For example, gravity’s effects on Earth at the equator are different, as the pull is weaker there.

Gravity is changing parts of our planet deep within the crust, shaping how the surface looks. Image source: rost9 / Adobe

As the ESA notes in an explainer on its website, gravity can vary from a minimum of 9.78 ms–2 at the equator to a maximum of 9.83 ms–2 at the poles. And now, with this new study, we may finally understand what causes these small but significant changes to how effects gravity has on Earth.

The researchers published their study in Nature Communications. In it, they argue that the role gravity has on changes we see in Earth’s crust is based on the effects gravity has on structures deep within the Earth. After all, the surface and inner levels of the Earth are not uniform throughout. Instead, different areas – like an ocean inside the Earth – can change how strong that structure is.

As a result, gravity can have an effect on the Earth’s crust by changing these structures deep beneath the surface. And with a better understanding of how gravity affects Earth as a whole, we may be able to find new ways to understand how gravity affects other planetary bodies out there, and perhaps even create artificial gravity on the Moon and other places we visit.