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Physics, Astronomy & Cosmology / Re: Distribution of Earth's mass?
« on: 25/02/2023 06:25:20 »
The NASA GRACE gravity map of the Earth (link from Kryptid above) shows deviations from an ideal Earth ellipsoid.
- They expect the equator to be farther from the axis of rotation (and it is, as surmised in the OP)
- They have subtracted that out, leaving only the deviations from a perfect ellipsoid.
However, because water flows downwards, the gravitational acceleration felt at mean sea level is fairly uniform around the world.
- Although there is more mass between the Sri Lanka and the center of the Earth than beneath Oslo...
- Sri Lanka gets a lift from Centrifugal force
- And Sri Lanka is farther from Earth's dense iron center
If there was some place in the ocean with higher surface gravity, the water would flow from there to a place with lower surface gravity (if you ignore things like ocean density differences and the effect of ocean gyres)...
- They expect the equator to be farther from the axis of rotation (and it is, as surmised in the OP)
- They have subtracted that out, leaving only the deviations from a perfect ellipsoid.
However, because water flows downwards, the gravitational acceleration felt at mean sea level is fairly uniform around the world.
- Although there is more mass between the Sri Lanka and the center of the Earth than beneath Oslo...
- Sri Lanka gets a lift from Centrifugal force
- And Sri Lanka is farther from Earth's dense iron center
If there was some place in the ocean with higher surface gravity, the water would flow from there to a place with lower surface gravity (if you ignore things like ocean density differences and the effect of ocean gyres)...
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