How does the gravity anomaly of an infinite slab of a constant thickness depend on its depth?

Question

I imagine this has something to do with bouguer correction. It kinda looks like the definition of bouguer correction, the B.C. depends on depth, but I wouldn't say that I know how a gravity anomaly of an infinite slab of constant thickness depends on depth!! Any help with this would be appreciated!!! Thanks in advance.

Answer 1

The gravitational pull between two objects varies according to the inverse distance square law.

Assume you have a body at a depth of 200m and the gravity reading from the meter at the Earth's surface is 16 units.

If you bury the same body at 400m depth ( twice the depth ) then the gravitational effect is reduced by a factor of 4.
That is the the depth is doubled (2 ) raised to the power of 2. And 2^2 =4. Therefore the new reading will be 16/4 = 4 units.

If the body is buried at 3 times the original depth the gravitational effect will be reduced to 1/9 th of the original value. Because 3^2 =9.
New value is therefore 16/9 = 1.78

Answer 2

Here's a good site that talks about gravity surveying that may help. I've included a few excerpts.

Gravity surveys measure the acceleration due to gravity, g. Average value of g at Earth’s surface is 9.80 ms-2.

Gravitational attraction depends on density of underlying rocks, so value of g varies across surface of Earth.

Density, r, is physical parameter to which gravity surveys are sensitive.

If the Earth were a uniform sphere g would be constant. However, gravity varies because the density varies within the Earth and the Earth is not a perfect sphere.

Density is increased by depth of burial:

Answer 3

All forces are simply the transfer of energy from one form to another. A lot of the forces are caused by the passing of particles between each other object according to the standard model. Gravity is, of course, different; they have not yet found a particle particular to gravity. But still in any place an object is, high ground or low ground, energy was put into it to get it up there, that is what we call potential energy. The higher it is to an reference object(the ground, a wooden floor, etc.) the more potential energy it has. So no matter what energy you get from gravity pulling water closer to earth the energy was already in the water.

Answer 4

I had asked the same question three times, and haven't got a proper answer