"Morenga" writes:

Does the gravity force only work unidirectional (towards the center of
the earth)

No. The gravitational acceleration at any point in space is (in some vague)
sense the "sum" of the gravitational accelrations produced by every object
in the visible universe, and there is no reason why it should always point
"inward." (In fact, for bodies inside their Roche's limit, there are points
where the net gravitational acceleration is "outward," which is why such bodies
may fall apart if the tidal forces exceed that body's tensile strength.)


or can outside forces (like the moon or the redistribution of ice/water
masses) also alter the distribution of mass inside the earth ?

Yes. We have a name for the re-distribution of matter caused by this "force:"
it is called "the lunar-induced tide."


Are there any known effects of the variations of earth distance from the sun
on the distribution of mass inside the earth?

Yes. It is called "the solar-induced tide."


We all know about the "bulge" ocean water suffers from these forces, I've
also read that moon vulcanism is caused by these grav tides.

There is _no_ reliable evidence that volcanism has occurred on the Moon
in aeons. There is evidence for occasional lava upwellings after asteroid
impacts, but that is not the same as volcanism.


Any known effects like this on earth?

The tidal deformation of the body of the Earth is called an "earth tide,"
just as the tidal deformation of the ocean is called an "ocean tide."


-- Gordon D. Pusch

perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;'