Gravity Is Not The Same Across The Planet

Contrary to what you may instantly think, the gravitational field of the Earth does not even extend across the entire planet. The gravitational field of Earth has very rough terrain, just like the surface of the planet, which has a variety of terrain.

This is due to a number of factors but is principally determined by the separation between the Earth's surface and its center. As a result, the Earth's gravity will actually somewhat decrease at the peak of a mountain because it is a little farther from the planet's center.

Mountain ranges, on the other hand, will typically have a higher gravitational field over a larger region because of the increased mass.

Additionally, as we already learned, the Earth is not perfectly spherical. If it were, the gravitational field would be roughly uniform everywhere. Due to centrifugal forces generated by the planet's rotation, gravity is also weaker at the planet's equator.