Compared to a featureless earth, how would you expect the mariana trench, the deepest trench in the ocean, to affect the gravitational force in that location?

Mariana trench is the deepest trench in the world. Now there is a difference of gravitational force between that of the earth surface and the trench. The reason is that the trench depth is about 10.9 Km and the radius measured from the surface to the center of the Earth is about 6,371 km.

So the trench is more deeper then the surface of earth and the pull of gravity will be different due to that reason inside that region.

Explanation:

Now, we can just subtract the depth of the trench from the radius "r" given, we get:

6,371×10³-10.9×10³ m = 6360.1 km,

Now simplifying the numbers (gravitational constant times mass of earth divided by that radius (6360100 m) squared.

We will get 9.8473 m/s².

The value of gravitational force will be 9.8473 m/s² inside Mariana trench